Metrics

You can use ArangoDB server metrics to monitor the healthiness and performance of the system

arangod exports metrics in the Prometheus format . The thresholds for alerts are described for relevant metrics.

The list of exposed metrics is subject to change in every minor version. While they should stay backwards compatible for the most part, some metrics are coupled to specific internals that may be replaced by other mechanisms in the future.

Whether the /_admin/metrics* endpoints are available depends on the setting of the --server.export-metrics-api startup option. For additional document read and write metrics, the --server.export-read-write-metrics startup option needs to be enabled.

Metrics API v2

Get the metrics

GET /_db/{database-name}/_admin/metrics/v2

Returns the instance’s current metrics in Prometheus format. The returned document collects all instance metrics, which are measured at any given time and exposes them for collection by Prometheus.

The document contains different metrics and metrics groups dependent on the role of the queried instance. All exported metrics are published with the prefix arangodb_ or rocksdb_ to distinguish them from other collected data.

The API then needs to be added to the Prometheus configuration file for collection.

Path Parameters

  • The name of a database. Which database you use doesn’t matter as long as the user account you authenticate with has at least read access to this database. If the --server.harden startup option is enabled, administrate access to the _system database is required.

Query Parameters

  • Returns metrics of the specified server. If no serverId is given, the asked server will reply. This parameter is only meaningful on Coordinators.

HTTP Headers
    Responses

    • Metrics were returned successfully.

    • The metrics API may be disabled using --server.export-metrics-api false setting in the server. In this case, the result of the call indicates the API to be not found.

    Examples

    curl --header 'accept: application/json' --dump - 'http://localhost:8529/_admin/metrics/v2'
    Show output

    AQL

    Total number of AQL queries finished

    arangodb_aql_all_query_total

    Total number of AQL queries finished. This metric was named arangodb_aql_all_query in previous versions of ArangoDB.

    Introduced in: v3.8.0

    Renamed from: arangodb_aql_all_query

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Current number of AQL queries executing

    arangodb_aql_current_query

    Current number of AQL queries executing.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    gaugenumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Current number of active AQL query cursors

    arangodb_aql_cursors_active

    Current number of active AQL query cursors. AQL query cursors are created for queries that produce more results than specified in the batchSize query option (default value: 1000). Such results can be fetched incrementally by client operations in chunks. As it is unclear if and when a client will fetch any remaining data from a cursor, every cursor has a server-side timeout value (TTL) after which it is garbage-collected.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    gaugenumbersimpleCoordinators, Agents and Single Servers

    Troubleshoot: This number can grow temporary in case a lot of concurrent AQL queries are executed. It should go down again however when the query results are consumed. If this number does not decrease a lot, it means that cursors are kept on the server and wait for their expiry. As active cursors can use resources (memory for query results and potentially some collection locks), it is advisable to check the client application code for ttl values and also check if the client application code fully consumes query results or only fetches them partially.

    Total memory usage of active AQL query result cursors

    arangodb_aql_cursors_memory_usage

    Total memory usage of active AQL query result cursors. This metric contains the memory usage of query result cursors that are created when a non-stream AQL query has finished and stores its result on the server for the client application to consume in batches.

    When an AQL query has finished building up its result, the initial batch of the result will be sent back to the client application. If the entire query result fits into a single batch, no cursor will be created and the query result will be returned to the client. If the query result is larger than a single batch, a server-side cursor is created, from which the client application can incrementally fetch more data. While that server-side cursor is present, its memory usage is counted in this metric.

    While an AQL query is executing and is building up its result, the memory usage of the query is included in the running query’s memoryUsage attribute and in the metric arangodb_aql_global_memory_usage.

    The memory usage of stream AQL queries is not included in this metric, because a stream AQL query does not build up its entire result first and then creates a cursor, but it will start executing and create a cursor already after building the first batch of results. The query will remain active until the entire result is consumed or the query gets aborted. While the query is active, its memory usage is included in its memoryUsage attribute and in the metric arangodb_aql_global_memory_usage.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    gaugebytessimpleCoordinators, Agents and Single Servers

    Total memory limit for all AQL queries combined

    arangodb_aql_global_memory_limit

    Total memory limit for all AQL queries combined, in bytes. If this value is reported as 0, it means there is no total memory limit in place for AQL queries. The value can be adjusted by the setting the --query.global-memory-limit startup option.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    gaugebytessimpleCoordinators, DB-Servers, Agents and Single Servers

    Total memory usage of all AQL queries executing; granularity: 32768 bytes steps

    arangodb_aql_global_memory_usage

    Total memory usage of all AQL queries currently executing. The granularity of this metric is steps of 32768 bytes. The current memory usage of all AQL queries is compared against the configured limit in the --query.global-memory-limit startup option. If the startup option has a value of 0, then no global memory limit are enforced. If the startup option has a non-zero value, queries are aborted once the total query memory usage goes above the configured limit.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    gaugebytessimpleCoordinators, DB-Servers, Agents and Single Servers

    Number of times the global query memory limit threshold was reached

    arangodb_aql_global_query_memory_limit_reached_total

    Total number of times the global query memory limit threshold was reached. This can happen if all running AQL queries in total try to use more memory than configured via the --query.global-memory-limit startup option. Every time this counter increases, an AQL query aborted with a “resource limit exceeded” error.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Number of times a local query memory limit threshold was reached

    arangodb_aql_local_query_memory_limit_reached_total

    Total number of times a local query memory limit threshold was reached, i.e. a single query tried to allocate more memory than configured in the query’s memoryLimit attribute or the value configured via the startup option --query.memory-limit. Every time this counter increases, an AQL query aborted with a “resource limit exceeded” error.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Execution time histogram for all AQL queries

    arangodb_aql_query_time (basename)
    arangodb_aql_query_time_bucket
    arangodb_aql_query_time_sum
    arangodb_aql_query_time_count

    Execution time histogram for all AQL queries, in seconds. The histogram includes all slow queries.

    Introduced in: v3.6.10

    TypeUnitComplexityExposed by
    histogramssimpleCoordinators, DB-Servers, Agents and Single Servers

    Execution time histogram for slow AQL queries

    arangodb_aql_slow_query_time (basename)
    arangodb_aql_slow_query_time_bucket
    arangodb_aql_slow_query_time_sum
    arangodb_aql_slow_query_time_count

    Execution time histogram for slow AQL queries, in seconds. Queries are considered “slow” if their execution time is above the threshold configured in the startup options --query.slow-threshold or --query.slow-streaming-threshold, respectively.

    Introduced in: v3.6.10

    TypeUnitComplexityExposed by
    histogramssimpleCoordinators, DB-Servers, Agents and Single Servers

    Total execution time of all AQL queries

    arangodb_aql_total_query_time_msec_total

    Total execution time of all AQL queries, in milliseconds, including all slow queries.

    Introduced in: v3.8.0

    Renamed from: arangodb_aql_total_query_time_msec

    TypeUnitComplexityExposed by
    countermssimpleCoordinators, DB-Servers, Agents and Single Servers

    Number of AQL queries which have been executed with dirty reads

    arangodb_dirty_read_queries_total

    This counter exposes the number of AQL queries which have been executed with “dirty reads”. A dirty read is one which may also use follower shards and not only leader shards. Note that it is the transaction in the context of which the AQL runs which determines, if dirty reads are allowed.

    Introduced in: v3.10.0

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators

    Agency

    Agency RAFT follower append time histogram

    arangodb_agency_append_hist (basename)
    arangodb_agency_append_hist_bucket
    arangodb_agency_append_hist_sum
    arangodb_agency_append_hist_count

    This measures the time an Agency follower needs for individual append operations resulting from AppendEntriesRPC requests. Every event contributes a measurement to the histogram, which also exposes the number of events and the total sum of all measurements.

    Introduced in: v3.7.1

    TypeUnitComplexityExposed by
    histogrammsmediumAgents

    Threshold: Normally these times should be clearly sub-second.

    Troubleshoot: If you see delays here, the Agents might not have enough IO bandwidth or might be overloaded. Try to provision more IOPS or more CPU capacity, potentially moving Agents to separate machines.

    Current number of entries in Agency cache callbacks table

    arangodb_agency_cache_callback_number

    This reflects the current number of callbacks the local AgencyCache has registered. This metric was named arangodb_agency_cache_callback_count in previous versions of ArangoDB.

    Introduced in: v3.8.0

    Renamed from: arangodb_agency_cache_callback_count

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers and Coordinators

    Threshold: This number is usually very low, something between 10 and 20.

    Troubleshoot: If this number is considerably higher, this should be investigated. Please contact support.

    Current number of Agency callbacks registered

    arangodb_agency_callback_number

    This metric reflects the current number of Agency callbacks being registered, including Agency cache callbacks. This metric was named arangodb_agency_callback_count in previous versions of ArangoDB.

    Introduced in: v3.8.0

    Renamed from: arangodb_agency_callback_count

    TypeUnitComplexityExposed by
    gaugenumberadvancedCoordinators and DB-Servers

    Threshold: This number is usually low, between 10 or 20. It can temporarily increase while there are ongoing DDL operations in the cluster. The number should go down again once the DDL operations have finished.

    Troubleshoot: If this number is considerably higher, this should be investigated. Please contact support.

    Total number of Agency callbacks ever registered

    arangodb_agency_callback_registered_total

    This metric was named arangodb_agency_callback_registered in previous versions of ArangoDB.

    Introduced in: v3.8.0

    Renamed from: arangodb_agency_callback_registered

    TypeUnitComplexityExposed by
    counternumberadvancedCoordinators and DB-Servers

    Current number of entries in Agency client id lookup table

    arangodb_agency_client_lookup_table_size

    Current number of entries in Agency client id lookup table. The lookup table is used internally for Agency inquire operations and should be compacted at the same time when the Agency’s in-memory log is compacted.

    Introduced in: v3.6.11

    TypeUnitComplexityExposed by
    gaugenumberadvancedAgents

    Agency RAFT commit histogram

    arangodb_agency_commit_hist (basename)
    arangodb_agency_commit_hist_bucket
    arangodb_agency_commit_hist_sum
    arangodb_agency_commit_hist_count

    Agency RAFT commit time histogram. Provides a distribution of commit times for all Agency write operations.

    Introduced in: v3.7.1

    TypeUnitComplexityExposed by
    histogrammsmediumAgents

    Agency compaction time histogram

    arangodb_agency_compaction_hist (basename)
    arangodb_agency_compaction_hist_bucket
    arangodb_agency_compaction_hist_sum
    arangodb_agency_compaction_hist_count

    Agency compaction time histogram. Provides a distribution of Agency compaction run times. Compactions are triggered after --agency.compaction-keep-size entries have accumulated in the RAFT log.

    Introduced in: v3.7.1

    TypeUnitComplexityExposed by
    histogrammsmediumAgents

    Troubleshoot: If compaction takes too long, it may be useful to reduce the number of log entries to keep in --agency.compaction-keep-size.

    This Agent’s commit index

    arangodb_agency_local_commit_index

    This Agent’s commit index (i.e. the index until it has advanced in the Agency’s RAFT protocol).

    Introduced in: v3.7.1

    TypeUnitComplexityExposed by
    gaugenumbersimpleAgents

    Agency replicated log size

    arangodb_agency_log_size_bytes

    Size of the Agency’s in-memory part of replicated log in bytes. The replicated log grows in memory until a certain number of log entries have been accumulated. Then the in-memory log is compacted. The number of in-memory log entries to keep before log compaction kicks in can be controlled via the startup option --agency.compaction-keep-size.

    Introduced in: v3.6.9

    TypeUnitComplexityExposed by
    gaugebytessimpleAgents

    Memory used by Agency store/cache

    arangodb_agency_node_memory_usage

    Amount of memory used to represent the Agency data structure. This measures memory usage on Agents, and also on Coordinators and DB-Servers because these have a cached version of the Agency’s Plan and Current sections.

    On Agency followers, this metric normally remains at a low value because the Agency key/value store is only built on Agency leaders.

    This metric can be non-zero even on single servers because there is a small initial memory allocation made at ArangoDB instance start.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    gaugebytehighCoordinators, DB-Servers and Agents

    Agency read operations with no leader or on followers

    arangodb_agency_read_no_leader_total

    Total number of Agency read operations with no leader or on followers.

    Introduced in: v3.8.0

    Renamed from: arangodb_agency_read_no_leader

    TypeUnitComplexityExposed by
    counternumbersimpleAgents

    Threshold: This should normally not happen. If it happens regularly, the Agency is reelecting its leader often.

    Troubleshoot: The latency of the network between the Agents might be too high or the Agents may be overloaded. It might help to move Agent instances to separate machines.

    Number of successful Agency read operations

    arangodb_agency_read_ok_total

    Number of Agency read operations which were successful (i.e. completed without any error). Successful reads can only be executed on the leader, so this metric is supposed to increase only on Agency leaders, but not on followers. Read requests that are executed on followers are rejected and can be tracked via the metric arangodb_agency_read_no_leader_total. This metric was named arangodb_agency_read_ok in previous versions of ArangoDB.

    Introduced in: v3.8.0

    Renamed from: arangodb_agency_read_ok

    TypeUnitComplexityExposed by
    counternumbersimpleAgents

    Counter for FailedServer jobs

    arangodb_agency_supervision_failed_server_total

    Counter for FailedServer jobs. This counter is increased whenever a supervision run encounters a failed server and starts a FailedServer job. This metric was named arangodb_agency_supervision_failed_server_count in previous versions of ArangoDB.

    Introduced in: v3.8.0

    Renamed from: arangodb_agency_supervision_failed_server_count

    TypeUnitComplexityExposed by
    counternumbermediumAgents

    Threshold: Many FailedServer jobs indicate frequent failures of DB-Servers. This is generally not good.

    Troubleshoot: Find the root cause of server failures. Overload and bad network latency can lead to misdetected server failures.

    Agency supervision runtime histogram

    arangodb_agency_supervision_runtime_msec (basename)
    arangodb_agency_supervision_runtime_msec_bucket
    arangodb_agency_supervision_runtime_msec_sum
    arangodb_agency_supervision_runtime_msec_count

    Agency supervision runtime histogram. A new value is recorded for each run of the supervision.

    Introduced in: v3.7.1

    TypeUnitComplexityExposed by
    histogrammssimpleAgents

    Threshold: The supervision runtime goes up linearly with the number of collections and shards.

    Agency supervision wait for replication time

    arangodb_agency_supervision_runtime_wait_for_replication_msec (basename)
    arangodb_agency_supervision_runtime_wait_for_replication_msec_bucket
    arangodb_agency_supervision_runtime_wait_for_replication_msec_sum
    arangodb_agency_supervision_runtime_wait_for_replication_msec_count

    Agency supervision replication time histogram. Whenever the Agency supervision carries out changes, it writes them to the leader’s log and replicates the changes to followers. This metric provides a histogram of the time it took to replicate the supervision changes to followers.

    Introduced in: v3.7.1

    TypeUnitComplexityExposed by
    histogrammsmediumAgents

    Agency’s term

    arangodb_agency_term

    The Agency’s current term.

    Introduced in: v3.7.1

    TypeUnitComplexityExposed by
    gaugenumbermediumAgents

    Threshold: This number should usually not grow. If it does, the Agency is doing repeated reelections, which suggests overload or bad network latency between Agents.

    Troubleshoot: It might help to reduce network latency between Agents or move Agent instances to separate machines.

    Agency write time histogram

    arangodb_agency_write_hist (basename)
    arangodb_agency_write_hist_bucket
    arangodb_agency_write_hist_sum
    arangodb_agency_write_hist_count

    Agency write time histogram. This histogram provides the distribution of the times spent in Agency write operations, in milliseconds. This only includes the time required to write the data into the leader’s log, but does not include the time required to replicate the writes to the followers.

    Introduced in: v3.7.1

    TypeUnitComplexityExposed by
    histogrammsmediumAgents

    Agency write operations with no leader or on followers

    arangodb_agency_write_no_leader_total

    Total number of Agency write operations with no leader or on followers.

    Introduced in: v3.8.0

    Renamed from: arangodb_agency_write_no_leader

    TypeUnitComplexityExposed by
    counternumbermediumAgents

    Threshold: This should normally not happen. If it happens regularly, the Agency is reelecting its leader often.

    Troubleshoot: The latency of the network between the Agents might be too high or the Agents may be overloaded. It might help to move Agent instances to separate machines.

    Number of successful Agency write operations

    arangodb_agency_write_ok_total

    Number of Agency write operations which were successful (i.e. completed without any error). Successful writes can only be executed on the leader, so this metric is supposed to increase only on Agency leaders, but not on followers. Write requests that are executed on followers are rejected and can be tracked via the metric arangodb_agency_write_no_leader_total. This metric was named arangodb_agency_write_ok in previous versions of ArangoDB.

    Introduced in: v3.8.0

    Renamed from: arangodb_agency_write_ok

    TypeUnitComplexityExposed by
    counternumbersimpleAgents

    ArangoSearch

    Average time of few last cleanups

    arangodb_search_cleanup_time

    Average time of few last cleanups.

    Introduced in: v3.10.0

    TypeUnitComplexityExposed by
    gaugemsadvancedDB-Servers and Single Servers

    ArangoSearch columns cache usage

    arangodb_search_columns_cache_size

    Size of all ArangoSearch columns currently loaded into the cache.

    Introduced in: v3.9.5

    TypeUnitComplexityExposed by
    gaugebytesadvancedDB-Servers and Single Servers

    Troubleshoot: If this metric contains a value close to configured --arangosearch.columns-cache-limit, there might be columns that are marked to be cached but do not fit into the cache. That may result in query performance degradation. Check the log for pattern “Failed to allocate memory for buffered column”

    Average time of few last commits

    arangodb_search_commit_time

    Average time of few last commits.

    Introduced in: v3.10.0

    TypeUnitComplexityExposed by
    gaugemsadvancedDB-Servers and Single Servers

    Average time of few last consolidations

    arangodb_search_consolidation_time

    Average time of few last consolidations.

    Introduced in: v3.10.0

    TypeUnitComplexityExposed by
    gaugemsadvancedDB-Servers and Single Servers

    Amount of memory in bytes that is used for consolidating this ArangoSearch index

    arangodb_search_consolidations_memory_usage

    Amount of memory in bytes that is used for consolidating an inverted index of a collection or an index of a View (arangosearch View link).

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    gaugebytesadvancedDB-Servers and Single Servers

    Number of ArangoSearch parallel execution threads requested by queries

    arangodb_search_execution_threads_demand

    This metric tracks the desired parallelism for SEARCH operations against Views. If the value is below the configured thread limit (--arangosearch.execution-threads-limit startup option), it coincides with the number of currently active threads.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers and Single Servers

    Troubleshoot: If this metric contains a value lower than the configured --arangosearch.execution-threads-limit (number of cores * 2 by default) then there are enough threads for running queries with parallel execution.

    If the value is greater than the limit, some queries can not get enough threads to achieve the requested parallelism currently. In this state, queries are less parallel up to single-threaded execution. Query performance might degrade.

    Current count of opened file descriptors for this ArangoSearch index

    arangodb_search_file_descriptors

    The number of active file descriptors used for an inverted index of a collection or an index of a View (arangosearch View link).

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers and Single Servers

    Size of the index in bytes for current snapshot

    arangodb_search_index_size

    Size of the index in bytes for current snapshot.

    Introduced in: v3.10.0

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers and Single Servers

    Amount of memory in bytes that is mapped for this ArangoSearch index

    arangodb_search_mapped_memory

    Amount of memory in bytes that is mapped for an inverted index of a collection or an index of a View (arangosearch View link) using memory-mapped files. The metric value is very approximate and can be outdated quickly.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    gaugebytesadvancedDB-Servers and Single Servers

    Number of documents for current snapshot

    arangodb_search_num_docs

    Number of documents for current snapshot.

    Introduced in: v3.10.0

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers and Single Servers

    Number of failed cleanups

    arangodb_search_num_failed_cleanups

    Number of failed cleanups.

    Introduced in: v3.10.0

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers and Single Servers

    Number of failed commits

    arangodb_search_num_failed_commits

    Number of failed commits.

    Introduced in: v3.10.0

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers and Single Servers

    Number of failed consolidations

    arangodb_search_num_failed_consolidations

    Number of failed consolidations.

    Introduced in: v3.10.0

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers and Single Servers

    Number of files for current snapshot

    arangodb_search_num_files

    Number of files for current snapshot.

    Introduced in: v3.10.0

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers and Single Servers

    Number of live documents for current snapshot

    arangodb_search_num_live_docs

    Number of live documents for current snapshot.

    Introduced in: v3.10.0

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers and Single Servers

    Number of out-of-sync arangosearch links/inverted indexes

    arangodb_search_num_out_of_sync_links

    Number of arangosearch View links and inverted indexes that are currently out of sync. A link or inverted index is out of sync if the recovery for it is intentionally skipped or a commit operation on the link/index has failed.

    Introduced in: v3.9.4

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers and Single Servers

    Troubleshoot: If this metric contains a value greater than zero, the log files should be checked to find out which links/indexes are affected. The out-of-sync links/indexes should then be dropped and recreated.

    Number of primary documents for current snapshot

    arangodb_search_num_primary_docs

    Number of primary documents for current snapshot.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers and Single Servers

    Number of segments for current snapshot

    arangodb_search_num_segments

    Number of segments for current snapshot.

    Introduced in: v3.10.0

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers and Single Servers

    Amount of memory in bytes that is used for reading from this ArangoSearch index

    arangodb_search_readers_memory_usage

    Amount of memory in bytes that is used for reading from an inverted index of a collection or an index of a View (arangosearch View link).

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    gaugebytesadvancedDB-Servers and Single Servers

    Amount of memory in bytes that is used for writing to this ArangoSearch index

    arangodb_search_writers_memory_usage

    Amount of memory in bytes that is used for writing to an inverted index of a collection or index of a View (arangosearch View link).

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    gaugebytesadvancedDB-Servers and Single Servers

    Connectivity

    Total number of connections created for connection pool

    arangodb_connection_pool_connections_created_total

    Total number of connections created for connection pool. There are two pools, one for the Agency communication with label AgencyComm and one for the other cluster internal communication with label ClusterComm.

    Introduced in: v3.8.0

    Renamed from: arangodb_connection_pool_connections_created

    TypeUnitComplexityExposed by
    counternumbermediumCoordinators and DB-Servers

    Threshold: Because of idle timeouts, the total number of connections ever created grows. However, under high load, most connections should usually be reused and a fast growth of this number can indicate underlying connectivity issues.

    Current number of connections in pool

    arangodb_connection_pool_connections_current

    Current number of connections in pool. There are two pools, one for the Agency communication with label AgencyComm and one for the other cluster internal communication with label ClusterComm.

    Introduced in: v3.8.0

    Renamed from: arangodb_connection_connections_current

    TypeUnitComplexityExposed by
    gaugenumbermediumCoordinators and DB-Servers

    Threshold: Normally, one should not see an excessive amount of open connections here, unless a very high amount of operations happens concurrently.

    Time to lease a connection from the connection pool

    arangodb_connection_pool_lease_time_hist (basename)
    arangodb_connection_pool_lease_time_hist_bucket
    arangodb_connection_pool_lease_time_hist_sum
    arangodb_connection_pool_lease_time_hist_count

    Time to lease a connection from the connection pool. There are two pools, one for the Agency communication with label AgencyComm and one for the other cluster internal communication with label ClusterComm.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    histogrammssimpleCoordinators and DB-Servers

    Threshold: Leasing connections from the pool should be fast, unless a new connection has to be formed, which can easily take (in particular with TLS) several milliseconds. If times are a lot higher, then some underlying network problem might be there.

    Total number of failed connection leases

    arangodb_connection_pool_leases_failed_total

    Total number of failed connection leases. There are two pools, one for the Agency communication with label AgencyComm and one for the other cluster internal communication with label ClusterComm.

    Introduced in: v3.8.0

    Renamed from: arangodb_connection_pool_leases_failed

    TypeUnitComplexityExposed by
    counternumbermediumCoordinators and DB-Servers

    Threshold: A failed lease can happen if a connection has been terminated by some idle timeout or if it is already in use by some other request. Since this can happen under concurrent load, failed leases are not actually very worrying.

    Total number of successful connection leases from connection pool

    arangodb_connection_pool_leases_successful_total

    Total number of successful connection leases from connection pool. There are two pools, one for the Agency communication with label AgencyComm and one for the other cluster internal communication with label ClusterComm.

    Introduced in: v3.8.0

    Renamed from: arangodb_connection_leases_successful

    TypeUnitComplexityExposed by
    counternumbermediumCoordinators and DB-Servers

    Threshold: It is normal that this number is growing rapidly when there is any kind of activity in the cluster.

    Total number of HTTP/1.1 connections accepted

    arangodb_http1_connections_total

    Total number of connections accepted for HTTP/1.1. Note that this can include connections that are negotiated to be upgraded to HTTP/2.

    Introduced in: v3.10.2

    TypeUnitComplexityExposed by
    counternumbermediumCoordinators, DB-Servers, Agents and Single Servers

    Total number of HTTP/2 connections accepted

    arangodb_http2_connections_total

    Total number of connections accepted for HTTP/2, this can be upgraded connections from HTTP/1.1 or connections negotiated to be HTTP/2 during the TLS handshake.

    Introduced in: v3.7.15

    TypeUnitComplexityExposed by
    counternumbermediumCoordinators, DB-Servers, Agents and Single Servers

    Errors

    Total number of errors logged

    arangodb_logger_errors_total

    Total number of errors (ERR messages) logged by the logger.

    If a problem is encountered which is fatal to some operation, but not for the service or the application as a whole, then an _error is logged.

    Reasons for log entries of this severity are for example include missing data, inability to open required files, incorrect connection strings, missing services.

    If an error is logged then it should be taken seriously as it may require user intervention to solve.

    Introduced in: v3.9.0

    TypeUnitComplexityExposed by
    counternumbersimpleAgents, Coordinators, DB-Servers and Single Servers

    Total number of warnings logged

    arangodb_logger_warnings_total

    Total number of warnings (WARN messages) logged by the logger, including startup warnings.

    Warnings might indicate problems, or might not. For example, expected transient environmental conditions such as short loss of network or database connectivity are logged as warnings, not errors.

    Introduced in: v3.9.0

    TypeUnitComplexityExposed by
    counternumbersimpleAgents, Coordinators, DB-Servers and Single Servers

    Health

    Number of drop-follower events

    arangodb_dropped_followers_total

    Total number of drop-follower events. This metric is increased on leaders whenever a write operation cannot be replicated to a follower during synchronous replication, and it would be unsafe in terms of data consistency to keep that follower. This metric was named arangodb_dropped_followers_count in previous versions of ArangoDB.

    Introduced in: v3.8.0

    Renamed from: arangodb_dropped_followers_count

    TypeUnitComplexityExposed by
    counternumbersimpleDB-Servers

    Threshold: Usually, drop-follower events should only happen if servers are restarted or if there are real problems on followers.

    Total number of failed heartbeat transmissions

    arangodb_heartbeat_failures_total

    Total number of failed heartbeat transmissions. Servers in a cluster periodically send their heartbeats to the Agency to report their own liveliness. This counter gets increased whenever sending such a heartbeat fails.

    Introduced in: v3.8.0

    Renamed from: arangodb_heartbeat_failures

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators and DB-Servers

    Threshold: It is a bad sign for health if heartbeat transmissions fail. This can lead to failover actions which are ultimately bad for the service.

    Troubleshoot: This can be a sign of overload or of bad network connectivity. Potentially move the Agent instances to separate machines.

    Time required to send a heartbeat

    arangodb_heartbeat_send_time_msec (basename)
    arangodb_heartbeat_send_time_msec_bucket
    arangodb_heartbeat_send_time_msec_sum
    arangodb_heartbeat_send_time_msec_count

    Histogram of times required to send heartbeats. For every heartbeat sent the time is measured and an event is put into the histogram.

    Introduced in: v3.7.1

    TypeUnitComplexityExposed by
    histogrammsmediumCoordinators and DB-Servers

    Threshold: It is a bad sign for health if heartbeat transmissions are not fast. If there are heartbeats which frequently take longer than a few hundred milliseconds, or even seconds, this can eventually lead to failover actions which are ultimately bad for the service.

    Troubleshoot: High heartbeat send times can be a sign of overload or of bad network connectivity. Potentially move the Agent instances to separate machines.

    Number of delays in the io heartbeat test

    arangodb_ioheartbeat_delays_total

    This counter is increased whenever the io heartbeat encounters a delay of at least 1s when writing a small file to the database directory, reading it and then removing it again. This test is done periodically to ensure that the underlying volume is usable and performs reasonably well. The test can be switched off explicitly with the flag --database.io-heartbeat=false, but the default is true. Furthermore, every such failure leads to a line in the log at INFO level for the ENGINES topic.

    Introduced in: v3.8.7

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers, Agents and Single Servers

    Histogram of execution times of a single IO heartbeat check

    arangodb_ioheartbeat_duration (basename)
    arangodb_ioheartbeat_duration_bucket
    arangodb_ioheartbeat_duration_sum
    arangodb_ioheartbeat_duration_count

    This histogram is updated whenever the io heartbeat runs its test in the database directory. It writes a small file, syncs it to durable storage, reads it, and then unlinks the file again. This test is done periodically to ensure that the underlying volume is usable and performs reasonably well. The test can be switched off explicitly with the flag --database.io-heartbeat=false, but the default is true.

    Introduced in: v3.8.7

    TypeUnitComplexityExposed by
    histogramusmediumDB-Servers, Agents and Single Servers

    Number of failures in the io heartbeat test

    arangodb_ioheartbeat_failures_total

    This counter is increased whenever the io heartbeat encounters a problem when writing a small file to the database directory, reading it and then removing it again. This test is done periodically to ensure that the underlying volume is usable. The test can be switched off explicitly with the flag --database.io-heartbeat=false, but the default is true. Furthermore, every such failure leads to a line in the log at INFO level for the ENGINES topic.

    Introduced in: v3.8.7

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers, Agents and Single Servers

    License

    This instance’s license expiry in days

    arangodb_license_expires

    This instance’s remaining license validity time.

    Introduced in: v3.9.1

    TypeUnitComplexityExposed by
    gaugenumbersimpleCoordinators and DB-Servers

    Maintenance

    Current loading runtimes

    arangodb_load_current_runtime (basename)
    arangodb_load_current_runtime_bucket
    arangodb_load_current_runtime_sum
    arangodb_load_current_runtime_count

    Histogram of Current loading runtimes, i.e. the runtimes of the ClusterInfo::loadCurrent internal method. Provides a distribution of all loading times for the Current section of the Agency data. The Current section gets loaded on server startup, and then gets reloaded on servers only for any databases in which there have been recent structural changes (i.e. DDL changes).

    Introduced in: v3.7.1

    TypeUnitComplexityExposed by
    histogrammsmediumCoordinators and DB-Servers

    Troubleshoot: In case this histogram contains very high loading times, this may be due to using many collections or many shards inside a database for which there are often structural changes. It then may make sense to reduce the number of collections or number of shards. Note that this can have other effects, so it requires an informed decision.

    Plan loading runtimes

    arangodb_load_plan_runtime (basename)
    arangodb_load_plan_runtime_bucket
    arangodb_load_plan_runtime_sum
    arangodb_load_plan_runtime_count

    Histogram of Plan loading runtimes, i.e. the runtimes of the ClusterInfo::loadPlan internal method. Provides a distribution of all loading times for the Plan section of the Agency data. The Plan section normally gets loaded on server startup, and then gets reloaded on servers only for any databases in which there have been recent structural changes (i.e. DDL changes).

    Introduced in: v3.7.1

    TypeUnitComplexityExposed by
    histogrammsmediumCoordinators and DB-Servers

    Troubleshoot: In case this histogram contains very high loading times, this may be due to using many collections or many shards inside a database for which there are often structural changes. It then may make sense to reduce the number of collections or number of shards. Note that this can have other effects, so it requires an informed decision.

    Counter of actions that are done and have been removed from the registry

    arangodb_maintenance_action_done_total

    DB-Servers execute reconciliation actions to let the cluster converge to the desired state. Actions are created, registered, queued and executed. Once they are done, they are eventually removed.

    This metric counts the number of actions that are done and have been removed.

    Introduced in: v3.8.0

    Renamed from: arangodb_maintenance_action_done_counter

    TypeUnitComplexityExposed by
    counternumbersimpleDB-Servers

    Counter of actions that have been discarded because of a duplicate

    arangodb_maintenance_action_duplicate_total

    DB-Servers execute reconciliation actions to let the cluster converge to the desired state. Actions are created, registered, queued and executed. Once they are done, they are eventually removed.

    This metric counts the number of actions that have been created but found to be a duplicate of a already queued action.

    Introduced in: v3.8.0

    Renamed from: arangodb_maintenance_action_duplicate_counter

    TypeUnitComplexityExposed by
    counternumberadvancedDB-Servers

    Failure counter for the maintenance actions

    arangodb_maintenance_action_failure_total

    DB-Servers execute reconciliation actions to let the cluster converge to the desired state. Actions are created, registered, queued and executed. Once they are done, they are eventually removed.

    Those action can fail for different reasons. This metric counts the failed actions and can thus provide hints to investigate a malfunction.

    Introduced in: v3.8.0

    Renamed from: arangodb_maintenance_action_failure_counter

    TypeUnitComplexityExposed by
    counternumbersimpleDB-Servers

    Time spent in the queue before execution for maintenance actions

    arangodb_maintenance_action_queue_time_msec (basename)
    arangodb_maintenance_action_queue_time_msec_bucket
    arangodb_maintenance_action_queue_time_msec_sum
    arangodb_maintenance_action_queue_time_msec_count

    DB-Servers execute reconciliation actions to let the cluster converge to the desired state. Actions are created, registered, queued and executed. Once they are done, they are eventually removed.

    This metric tracks the time actions spend waiting in the queue in a histogram.

    Introduced in: v3.7.1

    TypeUnitComplexityExposed by
    histogrammsadvancedDB-Servers

    Counter of actions that have been registered in the action registry

    arangodb_maintenance_action_registered_total

    DB-Servers execute reconciliation actions to let the cluster converge to the desired state. Actions are created, registered, queued and executed. Once they are done, they are eventually removed.

    This metric counts the number of actions that are queued or active.

    Introduced in: v3.8.0

    Renamed from: arangodb_maintenance_action_registered_counter

    TypeUnitComplexityExposed by
    counternumbersimpleDB-Servers

    Time spent executing a maintenance action

    arangodb_maintenance_action_runtime_msec (basename)
    arangodb_maintenance_action_runtime_msec_bucket
    arangodb_maintenance_action_runtime_msec_sum
    arangodb_maintenance_action_runtime_msec_count

    DB-Servers execute reconciliation actions to let the cluster converge to the desired state. Actions are created, registered, queued and executed. Once they are done, they are eventually removed.

    This metric tracks the time actions spend executing in a histogram.

    Introduced in: v3.7.1

    TypeUnitComplexityExposed by
    histogrammsadvancedDB-Servers

    Total time spent on Agency sync

    arangodb_maintenance_agency_sync_runtime_msec (basename)
    arangodb_maintenance_agency_sync_runtime_msec_bucket
    arangodb_maintenance_agency_sync_runtime_msec_sum
    arangodb_maintenance_agency_sync_runtime_msec_count

    DB-Servers execute reconciliation actions to let the cluster converge to the desired state. To identify the target state differences in the meta data store provided by the Agency are investigated and local changes are reported. This process is called Agency sync and is executed in regular intervals.

    This metric tracks the runtime of individual Agency syncs in a histogram. During DDL operations the runtime can increase but should generally be below 1s.

    Introduced in: v3.7.1

    TypeUnitComplexityExposed by
    histogrammssimpleDB-Servers

    Maintenance Phase 1 runtime histogram

    arangodb_maintenance_phase1_runtime_msec (basename)
    arangodb_maintenance_phase1_runtime_msec_bucket
    arangodb_maintenance_phase1_runtime_msec_sum
    arangodb_maintenance_phase1_runtime_msec_count

    DB-Servers execute reconciliation actions to let the cluster converge to the desired state. To identify the target state differences in the meta data store provided by the Agency are investigated and local changes are reported. This process is called Agency sync and is executed in regular intervals.

    This metric tracks the runtime of phase1 of an Agency sync. Phase1 calculates the difference between the local and the target state.

    Introduced in: v3.7.1

    TypeUnitComplexityExposed by
    histogrammsadvancedDB-Servers

    Maintenance Phase 2 runtime histogram

    arangodb_maintenance_phase2_runtime_msec (basename)
    arangodb_maintenance_phase2_runtime_msec_bucket
    arangodb_maintenance_phase2_runtime_msec_sum
    arangodb_maintenance_phase2_runtime_msec_count

    DB-Servers execute reconciliation actions to let the cluster converge to the desired state. To identify the target state differences in the meta data store provided by the Agency are investigated and local changes are reported. This process is called Agency sync and is executed in regular intervals.

    This metric tracks the runtime of phase2 of an Agency sync. Phase2 calculates what actions to execute given the difference of the local and target state.

    Introduced in: v3.7.1

    TypeUnitComplexityExposed by
    histogrammsadvancedDB-Servers

    Network

    Request time for Agency requests

    arangodb_agencycomm_request_time_msec (basename)
    arangodb_agencycomm_request_time_msec_bucket
    arangodb_agencycomm_request_time_msec_sum
    arangodb_agencycomm_request_time_msec_count

    This histogram shows how long requests to the Agency took.

    Introduced in: v3.7.1

    TypeUnitComplexityExposed by
    histogrammsmediumCoordinators and DB-Servers

    Threshold: Usually, such requests should be relatively quick, mostly clearly sub-second.

    Troubleshoot: If the network or the Agents are overloaded, it can help to move Agent instances to separate machines.

    Number of failed connectivity check requests sent to Coordinators

    arangodb_network_connectivity_failures_coordinators_total

    Number of failed connectivity check requests sent by this instance to Coordinators. The metric will be increased if a cluster-internal connection to a Coordinator cannot be established within 10 seconds. In this case the instance will also log a warning. Connectivity checks run with a configurable frequency, adjustable via the --cluster.connectivity-check-interval startup option.

    Introduced in: v3.11.4

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators and DB-Servers

    Troubleshoot: If this metric keeps increasing permanently or for longer periods, there are likely network connectivity issues or misconfigurations, which can prevent the instance from connecting to every Coordinator in the cluster (potentially connecting to itself). In this case it is advised to check the connectivity manually, and ensure that the instance can make connections to all Coordinators, potentially including itself.

    If there are temporary network glitches or instance restarts, this metric can also increase. But increases should stop once the network has stabilized and/or instances have restarted successfully.

    Number of failed connectivity check requests sent to DB-Servers

    arangodb_network_connectivity_failures_dbservers_total

    Number of failed connectivity check requests sent by this instance to DB-Server. The metric will be increased if a cluster-internal connection to a DB-Server cannot be established within 10 seconds. In this case the instance will also log a warning. Connectivity checks run with a configurable frequency, adjustable via the --cluster.connectivity-check-interval startup option.

    Introduced in: v3.11.4

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators and DB-Servers

    Troubleshoot: If this metric keeps increasing permanently or for longer periods, there are likely network connectivity issues or misconfigurations, which can prevent the instance from connecting to every DB-Server in the cluster (potentially connecting to itself). In this case it is advised to check the connectivity manually, and ensure that the instance can make connections to all DB-Servers, potentially including itself.

    If there are temporary network glitches or instance restarts, this metric can also increase. But increases should stop once the network has stabilized and/or instances have restarted successfully.

    Internal request duration for the dequeue in seconds

    arangodb_network_dequeue_duration (basename)
    arangodb_network_dequeue_duration_bucket
    arangodb_network_dequeue_duration_sum
    arangodb_network_dequeue_duration_count

    Histogram providing the time from submitting an internal requests until the IO thread in the fuerte driver starts working on it. Times are in seconds.

    Introduced in: v3.10.6

    TypeUnitComplexityExposed by
    histogramsecondsadvancedCoordinators, DB-Servers and Agents

    Troubleshoot: Counts in the high brackets indicate that the IO threads cannot keep up with the work.

    Number of requests forwarded to another Coordinator

    arangodb_network_forwarded_requests_total

    Number of requests forwarded to another Coordinator. Request forwarding can happen in load-balanced setups, when one Coordinator receives and forwards requests that can only be handled by a different Coordinator. This includes requests for streaming transactions, AQL, query cursors, Pregel jobs and some others.

    Introduced in: v3.8.0

    Renamed from: arangodb_network_forwarded_requests

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators

    Internal request round-trip time as a percentage of timeout

    arangodb_network_request_duration_as_percentage_of_timeout

    Histogram providing the round-trip time of internal requests as a percentage of the respective request timeout. This metric provides values between 0 and 100.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    gaugepercentageadvancedCoordinators, DB-Servers and Agents

    Troubleshoot: High values indicate problems with requests that have timed out or have not been far away from running into timeouts. If many requests timeout, this is normally a symptom of overload. This can normally be mitigated by reducing the workload or adjusting the type of operations that are causing the high response times. If the timeouts happen as a result of not enough processing power, it may be useful to scale up the cluster.

    Number of internal requests that have timed out

    arangodb_network_request_timeouts_total

    Number of internal requests that have timed out. This metric is increased whenever any cluster-internal request executed in the underlying connection pool runs into a timeout.

    Introduced in: v3.8.0

    Renamed from: arangodb_network_request_timeouts

    TypeUnitComplexityExposed by
    counternumbermediumCoordinators, DB-Servers and Agents

    Troubleshoot: Request timeouts can be caused by the destination servers being overloaded and thus slow to respond, or by network errors. If this counter increases, it is advised to check network connectivity and server loads.

    Number of outgoing internal requests in flight

    arangodb_network_requests_in_flight

    Number of outgoing internal requests in flight. This metric is increased whenever any cluster-internal request is about to be sent via the underlying connection pool, and is decreased whenever a response for such a request is received or the request runs into a timeout. This metric provides an estimate of the fan-out of operations. For example, a user operation on a collection with a single shard normally leads to a single internal request (plus replication), whereas an operation on a collection with 10 shards may lead to a fan-out of 10 (plus replication).

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    gaugenumbermediumCoordinators, DB-Servers and Agents

    Internal request duration from fully sent till response received in seconds

    arangodb_network_response_duration (basename)
    arangodb_network_response_duration_bucket
    arangodb_network_response_duration_sum
    arangodb_network_response_duration_count

    Histogram providing the time from when the request was fully sent off until the response has been received of internal requests in seconds.

    Introduced in: v3.10.6

    TypeUnitComplexityExposed by
    histogramsecondsadvancedCoordinators, DB-Servers and Agents

    Troubleshoot: Counts in the high brackets indicate problems with the network infrastructure.

    Internal request send duration in seconds

    arangodb_network_send_duration (basename)
    arangodb_network_send_duration_bucket
    arangodb_network_send_duration_sum
    arangodb_network_send_duration_count

    Histogram providing the sending time of internal requests in seconds.

    Introduced in: v3.10.6

    TypeUnitComplexityExposed by
    histogramsecondsadvancedCoordinators, DB-Servers and Agents

    Troubleshoot: Counts in the high brackets indicate problems with the network infrastructure.

    Number of internal requests for which sending has not finished

    arangodb_network_unfinished_sends_total

    Number of internal requests for which sending has not finished. This is usually due to some connection problem or to a timeout in case the receiving side did not receive the data fast enough.

    Introduced in: v3.10.6

    TypeUnitComplexityExposed by
    counternumberadvancedCoordinators, DB-Servers and Agents

    Troubleshoot: If this counter moves, it is a sign that either there are delays in the networking infrastructure or on the receiving side.

    Replication

    Total number of collection truncate operations by synchronous replication

    arangodb_collection_truncates_replication_total

    Total number of collection truncate operations by synchronous replication on followers. Note that this metric is only present when the command line option --server.export-read-write-metrics is set to true.

    Introduced in: v3.8.0

    Renamed from: arangodb_collection_truncates_replication

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers

    Total number of document write operations by synchronous replication

    arangodb_document_writes_replication_total

    Total number of document write operations by synchronous replication. This metric is only present if the option --server.export-read-write-metrics is set to true. Total number of document write operations (insert, update, replace, remove) executed by the synchronous replication on followers. This metric is only present if the option --server.export-read-write-metrics is set to true.

    Introduced in: v3.8.0

    Renamed from: arangodb_document_writes_replication

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers

    Current memory usage of all ongoing arangodump operations on the

    server

    arangodb_dump_memory_usage

    This metric shows the current memory usage of all ongoing parallel arangodump operations that are ongoing on the server. It will be increased whenever the server-side part of arangodump requests a large block of memory for storing dump results. It will only be increased on servers that host at least one of the collections/shards that is part of the dump. The value will be decreased whenever a dump result was successfully transfered to arangodump and arangodump has acknowledged its reception. The value will also go down when the server-side part of an abandoned arangodump operation time out and all its data is removed from memory.

    This metric will have a value of 0 on Coordinators. The metric will not be increased for any arangodump invocations that did not use the --parallel-dump option.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    gaugebytessimpleCoordinators, DB-Servers, Single Servers and Agents

    Troubleshoot: If the peak values reported by this metric are close to the memory limit configured via the startup option --dump.max-memory-usage, this indicates that dumps could operate faster when given more memory resources. In this case either increase the value of the startup option, which allows the server-side part of arangodump to buffer more results in memory, or reduce the number of batches to prefetch when invoking arangodump.

    Note also that values reported by this metric may temporarily be slightly above the configured memory usage limit to guarantee progress of dump operations.

    Number of currently ongoing arangodump operations on the

    server

    arangodb_dump_ongoing

    This metric shows the number of currently ongoing parallel arangodump operations that are ongoing on the server. It will be increased whenever arangodump is invoked with the --parallel-dump option and the server hosts at least one collection/shard that is part of the dump. The value will be decreased whenever a parallel arangodump operation finishes, or if it is abandoned, after the timeout value used for the server-side part of the dump operation.

    This metric will have a value of 0 on Coordinators. The metric will not be increased for any arangodump invocations that did not use the --parallel-dump option.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    gaugenumbersimpleCoordinators, DB-Servers, Single Servers and Agents

    Number of times a server-side dump thread was blocked

    because it honored the server-side memory limit for dumps

    arangodb_dump_threads_blocked_total

    This metric will be increased whenever a server-side dump thread tries to prefetch more data from the database and makes it ready to use for fetching, but doing so would violate the configured per-server memory limit for all ongoing arangodump invocations.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    counternumberadvancedCoordinators, DB-Servers, Single Servers and Agents

    Troubleshoot: If this metric keeps increasing drastically, it is an indication that the server could buffer and provide dump responses faster than it is allowed to. The two ways of fixing this problem are to increase the amount of memory that dumps can use, by increasing the value of the --dump.max-memory-usage startup option, to reduce the number of parallel threads used in an arangodump invocation, or to start less concurrent arangodumps.

    This metric will have a value of 0 on Coordinators. It will also not be increased for arangodump invocations that did not use --parallel-dump option.

    Number of refusal answers from a follower during synchronous replication

    arangodb_refused_followers_total

    Number of refusal answers from a follower during synchronous replication. A refusal answer is only sent by a follower if the follower is under the impression that the replication request was not sent by the current shard leader. This can happen if replication requests to the follower are delayed or the follower is slow to process incoming requests and there was a leader change for the shard. If such a refusal answer is received by the shard leader, it drops the follower from the list of followers. This metrics was named arangodb_refused_followers_count in previous versions of ArangoDB.

    Introduced in: v3.8.0

    Renamed from: arangodb_refused_followers_count

    TypeUnitComplexityExposed by
    counternumberadvancedDB-Servers

    Threshold: Usually, refusal answers only occur if request processing on followers is delayed and there was a recent leadership change. This should not be a common case and normally indicates a problem with the setup or with the load.

    Number of bytes of replicated log data stored in memory

    arangodb_replication2_leader_in_memory_bytes

    Number of bytes of replicated log data stored in memory.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    gaugebytesmediumDB-Servers

    Number of log entries stored in memory

    arangodb_replication2_leader_in_memory_entries

    Number of log entries stored in memory.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    gaugenumbermediumDB-Servers

    Histogram of the number of entries in an append-entries message

    arangodb_replication2_replicated_log_append_entries_num_entries (basename)
    arangodb_replication2_replicated_log_append_entries_num_entries_bucket
    arangodb_replication2_replicated_log_append_entries_num_entries_sum
    arangodb_replication2_replicated_log_append_entries_num_entries_count

    The leader of a replicated log replicates the log entries by sending append-entries requests to its followers. This is a histogram keeping track of the number of log entries in those requests.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    histogramnumbermediumDB-Servers

    Histogram of the RTT of appendEntries requests in microseconds

    arangodb_replication2_replicated_log_append_entries_rtt (basename)
    arangodb_replication2_replicated_log_append_entries_rtt_bucket
    arangodb_replication2_replicated_log_append_entries_rtt_sum
    arangodb_replication2_replicated_log_append_entries_rtt_count

    The leader of a replicated log replicates the log entries by sending appendEntries requests to its followers. This is a histogram keeping track of the number of such requests this server sends (for any log it is a leader of), as well as their respective round-trip times in microseconds.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    histogramusmediumDB-Servers and Single Servers

    Histogram of the size of append-entries message

    arangodb_replication2_replicated_log_append_entries_size (basename)
    arangodb_replication2_replicated_log_append_entries_size_bucket
    arangodb_replication2_replicated_log_append_entries_size_sum
    arangodb_replication2_replicated_log_append_entries_size_count

    The leader of a replicated log replicates the log entries by sending append-entries requests to its followers. This is a histogram keeping track of the size of those messages.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    histogrambytesmediumDB-Servers

    Number of replicated log instances created on this server since its start

    arangodb_replication2_replicated_log_creation_total

    Number of replicated log instances created on this server since its start.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    counternumbersimpleDB-Servers and Single Servers

    Number of replicated log instances deleted on this server since its start

    arangodb_replication2_replicated_log_deletion_total

    Number of replicated log instances deleted on this server since its start.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    counternumbersimpleDB-Servers and Single Servers

    Histogram of the duration of appendEntries calls in microseconds

    arangodb_replication2_replicated_log_follower_append_entries_rt (basename)
    arangodb_replication2_replicated_log_follower_append_entries_rt_bucket
    arangodb_replication2_replicated_log_follower_append_entries_rt_sum
    arangodb_replication2_replicated_log_follower_append_entries_rt_count

    Followers of a replicated log, including the local followers for persistence each leader has, receive appendEntries requests. These contain log entries to be replicated. Serving these requests means writing them to persistence.

    This histogram counts the number of such requests server by this server, plus their respective runtime in microseconds.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    histogramusadvancedDB-Servers and Single Servers

    Counter of how many entries have been dropped by a follower during an

    append-entries request

    arangodb_replication2_replicated_log_follower_entry_drop_total

    The leader of a replicated log replicates the log entries by sending append-entries requests to its followers. Sometimes followers have to drop existing log entries before appending the new log entries. This usually happens after a failover or leader change.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers

    Current number of followers of replicated logs

    arangodb_replication2_replicated_log_follower_number

    Current number of replicated logs this server is a follower of.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    gaugenumbersimpleDB-Servers and Single Servers

    Current number of inactive replicated logs

    arangodb_replication2_replicated_log_inactive_number

    Current number of replicated logs this server is a participant of, but is not yet configured to be either a leader or a follower. This number should usually be zero, except during server startup until the configuration from the Agency is fetched and applied, and for a short time when a log is newly created.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    gaugenumbersimpleDB-Servers and Single Servers

    Number of bytes inserted into replicated logs

    arangodb_replication2_replicated_log_inserts_bytes (basename)
    arangodb_replication2_replicated_log_inserts_bytes_bucket
    arangodb_replication2_replicated_log_inserts_bytes_sum
    arangodb_replication2_replicated_log_inserts_bytes_count

    For all replicated logs this server is a leader of, this counts the number of bytes of raw payload inserted into it.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    histogrambytesmediumDB-Servers and Single Servers

    Round-trip time of inserts into replicated logs in microseconds

    arangodb_replication2_replicated_log_inserts_rtt (basename)
    arangodb_replication2_replicated_log_inserts_rtt_bucket
    arangodb_replication2_replicated_log_inserts_rtt_sum
    arangodb_replication2_replicated_log_inserts_rtt_count

    Inserts into replicated logs this server is a leader of are counted by this histogram, plus their respective round-trip time. This includes the time for replication, at least until the writeConcern is satisfied.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    histogramusmediumDB-Servers and Single Servers

    Counter of failed append-entries messages

    arangodb_replication2_replicated_log_leader_append_entries_error_total

    The leader of a replicated log replicates the log entries by sending append-entries requests to its followers. This metric counts the amount of true failures, i.e. does not account for expected protocol errors that are handled gracefully.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers

    Current number of replicated log leaders

    arangodb_replication2_replicated_log_leader_number

    Number of replicated logs this server is currently a leader of.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    gaugenumbersimpleDB-Servers and Single Servers

    Number of leader takeovers

    arangodb_replication2_replicated_log_leader_took_over_total

    Number of times this server took over the leadership of a replicated log since server start.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers and Single Servers

    Number of replicated logs

    arangodb_replication2_replicated_log_number

    Number of replicated logs this server is a participant of.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    counternumbersimpleDB-Servers and Single Servers

    Number of accepted (not yet committed) log entries

    arangodb_replication2_replicated_log_number_accepted_entries_total

    The entries have been inserted into the log and are being replicated but a quorum has not yet been reached.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    counternumbersimpleDB-Servers

    Number of committed log entries

    arangodb_replication2_replicated_log_number_committed_entries_total

    Number of committed log entries.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    counternumbersimpleDB-Servers

    Number of compacted log entries

    arangodb_replication2_replicated_log_number_compacted_entries_total

    Number of compacted log entries. If log entries have been replicated to every participant and applied durably, they can be compacted, i.e. deleted.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    counternumbersimpleDB-Servers

    Number of meta log entries

    arangodb_replication2_replicated_log_number_meta_entries_total

    Number of meta log entries. A meta log entry is used to create artificial write barriers, for example during a configuration change or move shard operation.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    counternumbersimpleDB-Servers

    Number of times started following a replicated log

    arangodb_replication2_replicated_log_started_following_total

    Number of times this server started following a replicated log since server start.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers and Single Servers

    Number of errors during an acquire snapshot operation

    arangodb_replication2_replicated_state_acquire_snapshot_errors_total

    Number of errors during an acquire snapshot operation.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    counternumberadvancedDB-Servers

    Number of log entries applied to the internal state

    arangodb_replication2_replicated_state_applied_entries_total

    Number of log entries applied to the internal state.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    counternumberadvancedDB-Servers

    Number of errors during an apply entries operation

    arangodb_replication2_replicated_state_apply_entries_errors_total

    Number of errors during an apply entries operation.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    counternumberadvancedDB-Servers

    Histogram of the duration of acquireSnapshot calls in microseconds

    arangodb_replication2_replicated_state_follower_acquire_snapshot_rt (basename)
    arangodb_replication2_replicated_state_follower_acquire_snapshot_rt_bucket
    arangodb_replication2_replicated_state_follower_acquire_snapshot_rt_sum
    arangodb_replication2_replicated_state_follower_acquire_snapshot_rt_count

    Histogram of the duration of acquireSnapshot calls in microseconds. This measures the time a new follower takes to acquire a snapshot from the leader.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    histogramusadvancedDB-Servers

    Number of log entries not yet applied by the follower

    arangodb_replication2_replicated_state_follower_apply_debt

    Number of log entries not yet applied by the follower. If this number grows, the follower can’t keep up with the leader. This can explain slowdowns during writes.

    Introduced in: v3.10.0

    TypeUnitComplexityExposed by
    gaugenumbersimpleDB-Servers

    Histogram of the duration of applyEntries calls in microseconds

    arangodb_replication2_replicated_state_follower_apply_entries_rt (basename)
    arangodb_replication2_replicated_state_follower_apply_entries_rt_bucket
    arangodb_replication2_replicated_state_follower_apply_entries_rt_sum
    arangodb_replication2_replicated_state_follower_apply_entries_rt_count

    Histogram of the duration of applyEntries calls in microseconds. This measures the time a follower takes to apply log entries to its local state after they have been committed.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    histogramusadvancedDB-Servers

    Number of follower replicated states

    arangodb_replication2_replicated_state_follower_number

    Number of replicated states this server is a follower of.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    counternumbersimpleDB-Servers

    Number of followers waiting for the leader to acknowledge the current term

    arangodb_replication2_replicated_state_follower_waiting_for_leader_number

    Number of followers waiting for the leader to acknowledge the current term.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers

    Number of followers waiting for a snapshot transfer to complete

    arangodb_replication2_replicated_state_follower_waiting_for_snapshot_number

    Number of followers waiting for a snapshot transfer to complete.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers

    Number of leader replicated states

    arangodb_replication2_replicated_state_leader_number

    Number of replicated states this server is a leader of.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    counternumbersimpleDB-Servers

    Histogram of the duration of recoverEntries calls in microseconds

    arangodb_replication2_replicated_state_leader_recover_entries_rt (basename)
    arangodb_replication2_replicated_state_leader_recover_entries_rt_bucket
    arangodb_replication2_replicated_state_leader_recover_entries_rt_sum
    arangodb_replication2_replicated_state_leader_recover_entries_rt_count

    Histogram of the duration of recoverEntries calls in microseconds. This measures the time a new leader takes to recover from existing log entries after it was elected.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    histogramusadvancedDB-Servers

    Number of leaders waiting for recovery to be complete

    arangodb_replication2_replicated_state_leader_waiting_for_recovery_number

    Number of leaders waiting for recovery to be complete.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers

    Number of replicated states

    arangodb_replication2_replicated_state_number

    Number of replicated states this server is a participant of.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    counternumbersimpleDB-Servers

    Number of log entries processed by the follower

    arangodb_replication2_replicated_state_processed_entries_total

    Number of log entries processed by the follower.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    counternumberadvancedDB-Servers

    Number of worker threads persisting replicated logs

    arangodb_replication2_rocksdb_num_persistor_worker

    Number of worker threads persisting replicated logs.

    Introduced in: v3.10.0

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers

    Length of the queue of persistence requests issued by replicated logs towards RocksDB

    arangodb_replication2_rocksdb_queue_length

    Length of the queue of persistence requests issued by replicated logs towards RocksDB. If this list grows, RocksDB can’t keep up with the replicated logs.

    Introduced in: v3.10.0

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers

    Histogram containing the sync times in microseconds

    arangodb_replication2_rocksdb_sync_time (basename)
    arangodb_replication2_rocksdb_sync_time_bucket
    arangodb_replication2_rocksdb_sync_time_sum
    arangodb_replication2_rocksdb_sync_time_count

    Histogram containing the sync times in microseconds. This is the time a worker thread waited on the Sync call on RocksDB. This is only applicable if written with wait-for-sync.

    Introduced in: v3.10.0

    TypeUnitComplexityExposed by
    histogramusmediumDB-Servers

    Histogram containing the sizes of write batches issued

    arangodb_replication2_rocksdb_write_batch_size (basename)
    arangodb_replication2_rocksdb_write_batch_size_bucket
    arangodb_replication2_rocksdb_write_batch_size_sum
    arangodb_replication2_rocksdb_write_batch_size_count

    Histogram containing the sizes of write batches issued. Workers collect input from multiple replicated logs into a single write batch. This measures the size of the write batch. This allows to estimate the write rate.

    Introduced in: v3.10.0

    TypeUnitComplexityExposed by
    histogrambytemediumDB-Servers

    Histogram containing the write times in microseconds

    arangodb_replication2_rocksdb_write_time (basename)
    arangodb_replication2_rocksdb_write_time_bucket
    arangodb_replication2_rocksdb_write_time_sum
    arangodb_replication2_rocksdb_write_time_count

    Histogram containing the write times in microseconds. This is the time a worker thread waited on the Write call on RocksDB.

    Introduced in: v3.10.0

    TypeUnitComplexityExposed by
    histogramusmediumDB-Servers

    Histogram containing the latency of storage operations

    arangodb_replication2_storage_operation_latency (basename)
    arangodb_replication2_storage_operation_latency_bucket
    arangodb_replication2_storage_operation_latency_sum
    arangodb_replication2_storage_operation_latency_count

    Histogram containing the latency of storage operations.

    Introduced in: v3.10.0

    TypeUnitComplexityExposed by
    histogramusadvancedDB-Servers

    Number of currently connected/active replication clients

    arangodb_replication_clients

    This metric contains the number of currently active/connected replication clients that have started or are currently receiving data from this server for replication purposes.

    Introduced in: v3.10.5

    TypeUnitComplexityExposed by
    gaugenumbermediumSingle Servers and DB-Servers

    (DC-2-DC only) Number of times the database and collection overviews have been requested

    arangodb_replication_cluster_inventory_requests_total

    When using a DC-2-DC configuration of ArangoDB this metric is active on both data-centers. It indicates that the follower data-center periodically matches the available databases and collections in order to mirror them. If no DC-2-DC is set up this value is expected to be 0.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_cluster_inventory_requests

    TypeUnitComplexityExposed by
    counternumberadvancedCoordinators

    Troubleshoot: If you have a DC-2-DC installation, and this metric stays constant over a longer period of time in any of the two data centers this indicates that the follower data center is not properly connected anymore. The issue most likely is within the sync process on either of the two data-centers as they do not compare their inventory anymore. This gives no information about the healthiness of the ArangoDB cluster itself, please check other metrics for this.

    Accumulated time needed to apply asynchronously replicated data on initial synchronization of shards

    arangodb_replication_dump_apply_time_total

    Measures the time required to clone the existing leader copy of the data onto a new replica shard. It is only measured on the follower server. This time is expected to increase whenever new followers are created, e.g. increasing replication factor, shard redistribution.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_dump_apply_time

    TypeUnitComplexityExposed by
    countermsmediumDB-Servers

    Troubleshoot: This metric measures as typical operation to keep the cluster resilient, so no reaction is required. In a stable cluster situation (no outages, no collection modification) this metric should also be stable.

    Total number of bytes replicated in initial asynchronous phase

    arangodb_replication_dump_bytes_received_total

    During initial replication the existing data from the leader is copied asynchronously over to new shards. The amount of requests required to transport data to this server, as a replica for a shard, is counted here.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_dump_bytes_received

    TypeUnitComplexityExposed by
    counterbytesmediumDB-Servers

    Total number of documents replicated in initial asynchronous phase

    arangodb_replication_dump_documents_total

    During initial replication the existing data from the leader is copied asynchronously over to new shards. The amount of documents transported to this server, as a replica for a shard, is counted here.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_dump_documents

    TypeUnitComplexityExposed by
    counternumbersimpleDB-Servers

    Accumulated wait time for replication requests in initial asynchronous phase

    arangodb_replication_dump_request_time_total

    During initial replication the existing data from the leader is copied asynchronously over to new shards. The accumulated time the follower waited for the leader to send the data is counted here.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_dump_request_time

    TypeUnitComplexityExposed by
    countermsmediumDB-Servers

    Number of requests used in initial asynchronous replication phase

    arangodb_replication_dump_requests_total

    During initial replication the existing data from the leader is copied asynchronously over to new shards. The amount of data transported to this server, as a replica for a shard, is counted here.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_dump_requests

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers

    Number of failed connection attempts and response errors during initial

    asynchronous replication

    arangodb_replication_failed_connects_total

    During initial replication the existing data from the leader is copied asynchronously over to new shards. Whenever there is a communication issue between the follower and the leader of the shard, it is counted here for the follower. This communication issues cover failed connections or http errors, but they also cover invalid or unexpected data formats received on the follower.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_failed_connects

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers

    Threshold: In ideal situation this counter should be 0. It is expected to increase if there is server or network outage. However it is not guaranteed that this metric increases in such a situation.

    Troubleshoot: If this counter increases this typically indicates an issue with the communication between servers. If it is just occasionally an increase of one, it can be a simple network hiccup, if you see constant increases here that indicates serious issues. This also indicates that there is a shard trying to get into sync with the existing data, which cannot make progress. So you have only replicationFactor - 1 copies of the data right now. If more servers suffer outage you may lose data in this case.

    • First thing to check: Network connectivity, make sure all servers are online and the machines can communicate to one-another.
    • Second: Check ArangoDB logs of this server for more details, most likely you see WARN or ERROR messages in the replication log topic. If you contact ArangoDB support for this issue, it helps to include these servers logs as well.
    • Third: (Unlikely) If the logs contain unexpected format or value entries please check if you are running all ArangoDB DB-Servers within the same version of ArangoDB. Only upgrades of one minor version at a time are supported in general, so if you are running one server with a much newer / older version please upgrade all servers to the newest version.
    • Forth: If none of the above applies, please contact ArangoDB Support.

    Accumulated wait time for replication key chunks determination requests

    arangodb_replication_initial_chunks_requests_time_total

    This counter exhibits the accumulated wait time for replication key chunks determination requests, in milliseconds. This is part of the older (pre 3.8) initial replication protocol, which might still be used in 3.8 for collections which have been created by older versions.

    In this older protocol, the follower first fetches an overview over a shard from the leader. This does a full collection scan and divides the primary keys in the collection into equal sized chunks. Then, a checksum for each chunk is returned. The same is then done on the follower and the checksums are compared, chunk by chunk. For each chunk, for which the checksums do not match, the list of keys and revisions is fetched from the leader. This then enables the follower to fetch the actually needed documents and remove superfluous ones locally.

    This metric accumulates the time used for the initial step of getting the checksums for the key chunks.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_initial_chunks_requests_time

    TypeUnitComplexityExposed by
    countermsmediumDB-Servers

    Accumulated time needed to request replication docs data

    arangodb_replication_initial_docs_requests_time_total

    This counter exhibits the accumulated wait time for requesting actual documents for the initial replication, in milliseconds. This is part of the older (pre 3.8) initial replication protocol, which might still be used in 3.8 for collections which have been created by older versions.

    In this older protocol, the follower first fetches an overview over a shard from the leader. This does a full collection scan and divides the primary keys in the collection into equal sized chunks. Then, a checksum for each chunk is returned. The same is then done on the follower and the checksums are compared, chunk by chunk. For each chunk, for which the checksums do not match, the list of keys and revisions is fetched from the leader. This then enables the follower to fetch the actually needed documents and remove superfluous ones locally.

    This metric accumulates the time used for the final step of actually getting the needed documents.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_initial_docs_requests_time

    TypeUnitComplexityExposed by
    countermsmediumDB-Servers

    Accumulated time needed to apply replication initial sync insertions

    arangodb_replication_initial_insert_apply_time_total

    Accumulated time needed to apply replication initial sync insertions. This counter exhibits the accumulated wait time for actually inserting documents for the initial synchronization, in milliseconds. This is part of the older (pre 3.8) initial replication protocol, which might still be used in 3.8 for collections which have been created by older versions.

    In this older protocol, the follower first fetches an overview over a shard from the leader. This does a full collection scan and divides the primary keys in the collection into equal sized chunks. Then, a checksum for each chunk is returned. The same is then done on the follower and the checksums are compared, chunk by chunk. For each chunk, for which the checksums do not match, the list of keys and revisions is fetched from the leader. This then enables the follower to fetch the actually needed documents and remove superfluous ones locally.

    This metric accumulates the time used for the actual insertion of replicated documents on the follower.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_initial_insert_apply_time

    TypeUnitComplexityExposed by
    countermsmediumDB-Servers

    Accumulated wait time for replication keys requests

    arangodb_replication_initial_keys_requests_time_total

    This counter exhibits the accumulated wait time for fetching key lists for a chunk, in milliseconds. This is part of the older (pre 3.8) initial replication protocol, which might still be used in 3.8 for collections which have been created by older versions.

    In this older protocol, the follower first fetches an overview over a shard from the leader. This does a full collection scan and divides the primary keys in the collection into equal sized chunks. Then, a checksum for each chunk is returned. The same is then done on the follower and the checksums are compared, chunk by chunk. For each chunk, for which the checksums do not match, the list of keys and revisions is fetched from the leader. This then enables the follower to fetch the actually needed documents and remove superfluous ones locally.

    This metric accumulates the time used for the second step of getting lists of key/revision pairs for each chunk.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_initial_keys_requests_time

    TypeUnitComplexityExposed by
    countermsmediumDB-Servers

    Accumulated time needed to apply replication initial sync removals

    arangodb_replication_initial_remove_apply_time_total

    This counter exhibits the accumulated wait time for removing local documents during initial synchronization of a shard on the follower, in milliseconds. This is part of the older (pre 3.8) initial replication protocol, which might still be used in 3.8 for collections which have been created by older versions.

    In this older protocol, the follower first fetches an overview over a shard from the leader. This does a full collection scan and divides the primary keys in the collection into equal sized chunks. Then, a checksum for each chunk is returned. The same is then done on the follower and the checksums are compared, chunk by chunk. For each chunk, for which the checksums do not match, the list of keys and revisions is fetched from the leader. This then enables the follower to fetch the actually needed documents and remove superfluous ones locally.

    This metric accumulates the time used for the intermediate step of removing unneeded documents on the follower.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_initial_remove_apply_time

    TypeUnitComplexityExposed by
    countermsmediumDB-Servers

    Accumulated amount of bytes received in initial sync

    arangodb_replication_initial_sync_bytes_received_total

    This counter exhibits the accumulated number of bytes received for initial synchronization of shards. This is part of the older (pre 3.8) initial replication protocol, which might still be used in 3.8 for collections which have been created by older versions.

    In this older protocol, the follower first fetches an overview over a shard from the leader. This does a full collection scan and divides the primary keys in the collection into equal sized chunks. Then, a checksum for each chunk is returned. The same is then done on the follower and the checksums are compared, chunk by chunk. For each chunk, for which the checksums do not match, the list of keys and revisions is fetched from the leader. This then enables the follower to fetch the actually needed documents and remove superfluous ones locally.

    This metric accumulates number of bytes received for all three steps.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_initial_sync_bytes_received

    TypeUnitComplexityExposed by
    counterbytesmediumDB-Servers

    Number of documents inserted by replication initial sync

    arangodb_replication_initial_sync_docs_inserted_total

    This counter exhibits the total number of documents inserted on the follower during initial synchronization of shards. This is part of the older (pre 3.8) initial replication protocol, which might still be used in 3.8 for collections which have been created by older versions.

    In this older protocol, the follower first fetches an overview over a shard from the leader. This does a full collection scan and divides the primary keys in the collection into equal sized chunks. Then, a checksum for each chunk is returned. The same is then done on the follower and the checksums are compared, chunk by chunk. For each chunk, for which the checksums do not match, the list of keys and revisions is fetched from the leader. This then enables the follower to fetch the actually needed documents and remove superfluous ones locally.

    This metric accumulates the total number of documents inserted in the third step.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_initial_sync_docs_inserted

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers

    Number of documents removed by replication initial sync

    arangodb_replication_initial_sync_docs_removed_total

    This counter exhibits the total number of documents removed on the follower during initial synchronization of shards. This is part of the older (pre 3.8) initial replication protocol, which might still be used in 3.8 for collections which have been created by older versions.

    In this older protocol, the follower first fetches an overview over a shard from the leader. This does a full collection scan and divides the primary keys in the collection into equal sized chunks. Then, a checksum for each chunk is returned. The same is then done on the follower and the checksums are compared, chunk by chunk. For each chunk, for which the checksums do not match, the list of keys and revisions is fetched from the leader. This then enables the follower to fetch the actually needed documents and remove superfluous ones locally.

    This metric accumulates the total number of documents removed in the third step.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_initial_sync_docs_removed

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers

    Number of documents requested by replication initial sync

    arangodb_replication_initial_sync_docs_requested_total

    This counter exhibits the total number of documents fetched on the follower from the leader during initial synchronization of shards. This is part of the older (pre 3.8) initial replication protocol, which might still be used in 3.8 for collections which have been created by older versions.

    In this older protocol, the follower first fetches an overview over a shard from the leader. This does a full collection scan and divides the primary keys in the collection into equal sized chunks. Then, a checksum for each chunk is returned. The same is then done on the follower and the checksums are compared, chunk by chunk. For each chunk, for which the checksums do not match, the list of keys and revisions is fetched from the leader. This then enables the follower to fetch the actually needed documents and remove superfluous ones locally.

    This metric accumulates the total number of documents fetched from the leader in the third step.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_initial_sync_docs_requested

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers

    Number of replication initial sync docs requests

    arangodb_replication_initial_sync_docs_requests_total

    This counter exhibits the total number of times documents have been fetched on the follower from the leader during initial synchronization of shards. This is part of the older (pre 3.8) initial replication protocol, which might still be used in 3.8 for collections which have been created by older versions.

    In this older protocol, the follower first fetches an overview over a shard from the leader. This does a full collection scan and divides the primary keys in the collection into equal sized chunks. Then, a checksum for each chunk is returned. The same is then done on the follower and the checksums are compared, chunk by chunk. For each chunk, for which the checksums do not match, the list of keys and revisions is fetched from the leader. This then enables the follower to fetch the actually needed documents and remove superfluous ones locally.

    This metric accumulates the total number of times documents have been fetched from the leader in the third step.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_initial_sync_docs_requests

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers

    Number of replication initial sync keys requests

    arangodb_replication_initial_sync_keys_requests_total

    This counter exhibits the accumulated number of keys requests for initial synchronization of shards. This is part of the older (pre 3.8) initial replication protocol, which might still be used in 3.8 for collections which have been created by older versions.

    In this older protocol, the follower first fetches an overview over a shard from the leader. This does a full collection scan and divides the primary keys in the collection into equal sized chunks. Then, a checksum for each chunk is returned. The same is then done on the follower and the checksums are compared, chunk by chunk. For each chunk, for which the checksums do not match, the list of keys and revisions is fetched from the leader. This then enables the follower to fetch the actually needed documents and remove superfluous ones locally.

    This metric counts the number of times the follower fetches a list of keys for some chunk.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_initial_sync_keys_requests

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers

    Total number of synchronous replication requests

    arangodb_replication_synchronous_requests_total_number_total

    The total amount of all synchronous replication operation requests between DB-Servers being done.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_synchronous_requests_total_number

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers

    Total time needed for all synchronous replication requests

    arangodb_replication_synchronous_requests_total_time_total

    The total time needed for all synchronous replication requests between DB-Servers being done.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_synchronous_requests_total_time

    TypeUnitComplexityExposed by
    countermsmediumDB-Servers

    Accumulated time needed to apply replication tailing data

    arangodb_replication_tailing_apply_time_total

    The accumulated time needed to locally process the continuous replication log on a follower received from a replication leader.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_tailing_apply_time

    TypeUnitComplexityExposed by
    countermsmediumDB-Servers

    Troubleshoot: If you see unusual spikes here, the follower might not have enough IO bandwidth or might be overloaded. Try to provision more IOPS or more CPU capacity. Additionally, it could make sense to compare the value with all other available follower DB-Servers to detect potential differences.

    Accumulated number of bytes received for replication tailing requests

    arangodb_replication_tailing_bytes_received_total

    The accumulated number of bytes received from a leader for replication tailing requests. The higher the amount of bytes is, the more data is being processed afterwards on the follower DB-Server.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_tailing_bytes_received

    TypeUnitComplexityExposed by
    counterbytesmediumDB-Servers

    Troubleshoot: Compare this metric with all other related participating follower DB-Servers. If the given value on a DB-Server is considerable higher, you might want to think about rebalancing your data as the overall work might not be evenly distributed.

    Accumulated number of replication tailing document inserts/replaces processed

    arangodb_replication_tailing_documents_total

    The accumulated number of replication tailing document inserts/replaces processed on a follower.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_tailing_documents

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers

    Troubleshoot: Compare this metric with all other related participating follower DB-Servers. If the given value on a DB-Server is considerable higher, you might want to think about rebalancing your data as the overall work might not be evenly distributed. It is important to understand that this metric only enumerates the amount of documents and does not compare document sizes. Even if values compared to other DB-Servers may vary, work load could be fine. Therefore also check the metric arangodb_replication_tailing_bytes_received_total to have an overall and more precise picture.

    Number of replication tailing failures due to missing tick on leader

    arangodb_replication_tailing_follow_tick_failures_total

    The number of replication tailing failures due to missing tick on leader.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_tailing_follow_tick_failures

    TypeUnitComplexityExposed by
    counternumberadvancedDB-Servers

    Troubleshoot: If this is non-zero, action is required. A required follower tick is not present (potentially removed) on a leader DB-Server. Please check the related leader DB-Server log-files to identify the origin of the cause. It may be required to do a full re-sync and/or increase the number of historic logfiles on the leader(s).

    Number of replication tailing markers processed

    arangodb_replication_tailing_markers_total

    The number of replication tailing markers processed on a follower DB-Server. Markers are specific operations which are part of the write-ahead log (WAL). Example actions which are being used in markers: Create or drop a database. Create, drop, rename, change or truncate a collection. Create or drop an index. Create, drop, change a view. Start, commit or abort a transaction.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_tailing_markers

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers

    Number of replication tailing document removals processed

    arangodb_replication_tailing_removals_total

    The amount of document removal based marker operations on a follower DB-Server.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_tailing_removals

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers

    Aggregated wait time for replication tailing requests

    arangodb_replication_tailing_request_time_total

    Aggregated wait time for replication tailing requests.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_tailing_request_time

    TypeUnitComplexityExposed by
    countermsadvancedDB-Servers

    Troubleshoot: If you see unusual spikes here, please inspect potential network issues. It may help to increase network bandwidth and/or reduce network latency. In case there are no network issues, also check the load of the serving leader DB-Server, as well as the follower DB-Server, as they could potentially be overloaded and reaching hardware-based limits.

    Number of replication tailing requests

    arangodb_replication_tailing_requests_total

    The total amount of network replication tailing requests.

    Introduced in: v3.8.0

    Renamed from: arangodb_replication_tailing_requests

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers

    Total memory usage of buffered updates for all revision trees

    arangodb_revision_tree_buffered_memory_usage

    Total memory usage of buffered updates for all revision trees of collections/shards. When data in a collection/shard is modified, the changes to the revision trees are first buffered in memory and applied later after the operation commits. Buffered changes are applied to the revision trees in large chunks. Whenever the buffered changes are applied, memory is freed again and this metric should go down.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    gaugebytesadvancedDB-Servers, Agents and Single Servers

    Troubleshoot: If this metric keeps increasing, it is a sign that the instance cannot catch up with the write load.

    Number of revision tree hibernations

    arangodb_revision_tree_hibernations_total

    The revision trees of collections/shards are normally present in RAM in an uncompressed state. However, to reduce the memory usage of keeping all revision trees in RAM at the same time, revision trees can be put into “hibernation” mode. Any inactive revision tree is automatically hibernated by ArangoDB after a while. For the hibernation step, a revision tree is compressed in RAM, and only the compressed version is then kept. Later accesses of a compressed revision tree require uncompressing the tree again. This metric is increased whenever a revision tree is hibernated. This can happened many times during the lifetime of a revision tree.

    Introduced in: v3.8.5

    TypeUnitComplexityExposed by
    counternumberadvancedDB-Servers, Agents and Single Servers

    Total memory usage of all revision trees (both hibernated and uncompressed)

    arangodb_revision_tree_memory_usage

    Total memory usage of all revision trees for collections/shards. The revision trees of collections/shards are normally present in RAM in an uncompressed state. However, to reduce the memory usage of keeping all revision trees in RAM at the same time, revision trees can be put into “hibernation” mode. Any inactive revision tree is automatically hibernated by ArangoDB after a while. For the hibernation step, a revision tree is compressed in RAM, and only the compressed version is then kept. Later accesses of a compressed revision tree require uncompressing the tree again. This metrics reports the total memory usage of all revision trees, including both the hibernated and uncompressed forms).

    Introduced in: v3.8.5

    TypeUnitComplexityExposed by
    gaugebytessimpleDB-Servers, Agents and Single Servers

    Number of failed revision tree rebuilds

    arangodb_revision_tree_rebuilds_failure_total

    Number of failed background revision tree rebuilds. Ideally this value stays at 0, because if a revision tree rebuild fails, the system may stall and not be able to make progress in terms of WAL file collection. When the counter increases, an error message is also logged to the server logfile.

    Introduced in: v3.8.2

    TypeUnitComplexityExposed by
    counternumberadvancedDB-Servers, Agents and Single Servers

    Number of successful revision tree rebuilds

    arangodb_revision_tree_rebuilds_success_total

    Number of successful background revision tree rebuilds. Ideally this value stays at 0, because a revision tree rebuild indicates a problem with a collection/shard’s revision tree that has happened before.

    Introduced in: v3.8.2

    TypeUnitComplexityExposed by
    counternumberadvancedDB-Servers, Agents and Single Servers

    Number of revision tree resurrections

    arangodb_revision_tree_resurrections_total

    The revision trees of collections/shards are normally present in RAM in an uncompressed state. However, to reduce the memory usage of keeping all revision trees in RAM at the same time, revision trees can be put into “hibernation” mode. Any inactive revision tree is automatically hibernated by ArangoDB after a while. For the hibernation step, a revision tree is compressed in RAM, and only the compressed version is then kept. Later accesses of a compressed revision tree require uncompressing the tree again. This metric is increased whenever a revision tree is restored from its hibernated state back into an uncompressed form in RAM. This can happened many times during the lifetime of a revision tree.

    Introduced in: v3.8.5

    TypeUnitComplexityExposed by
    counternumberadvancedDB-Servers, Agents and Single Servers

    Number of leader shards on this machine

    arangodb_shards_leader_number

    Number of leader shards on this machine. Every shard has a leader and potentially multiple followers.

    Introduced in: v3.8.0

    Renamed from: arangodb_shards_leader_count

    TypeUnitComplexityExposed by
    gaugenumbersimpleCoordinators, DB-Servers and Agents

    Troubleshoot: Since the leaders perform all the read and write operations and the followers only replicate the writes, one should usually have a relatively even distribution of leader shards across DB-Servers. An exception can be one-shard deployments, in which every collection has a single shard and all shards in a database must have the same leader. If you have few databases in a one-shard deployment, then an uneven distribution of leader shards is natural.

    You can either move shards manually, use the Rebalance shards button in the ArangoDB web interface, or use the cluster maintenance tools  (create-move-plan and execute-move-plan specifically). In the latter case, contact ArangoDB customer support.

    Number of shards not replicated at all

    arangodb_shards_not_replicated

    Number of shards not replicated at all. This is counted for all shards for which this server is currently the leader. The number is increased by one for every shards for which no follower is in sync.

    Introduced in: v3.7.1

    TypeUnitComplexityExposed by
    gaugenumbersimpleCoordinators, DB-Servers and Agents

    Troubleshoot: Needless to say, such a situation is very bad for resilience, since it indicates a single point of failure. So, if this number is greater than 0, then some action is indicated. During an upgrade or when some DB-Server was restarted, it can happen that shard followers are out of sync. Normally, shards should get in sync on their own, so observation and waiting is a good measure at first. However, if the situation persists, something is wrong, potentially some constant server crash (maybe out of memory crashes?) or another situation preventing shards to get in sync. Contact ArangoDB customer support in this case.

    Number of shards on this machine

    arangodb_shards_number

    Number of shards on this machine. Every shard has a leader and potentially multiple followers. This metric counts both leader and follower shards.

    Introduced in: v3.8.0

    Renamed from: arangodb_shards_total_count

    TypeUnitComplexityExposed by
    gaugenumbersimpleDB-Servers

    Troubleshoot: Since both leader and follower shards use memory and disk space, the total number of shards should be approximately balanced evenly across the DB-Servers. To achieve this, you can either move shards manually, use the Rebalance shards button in the ArangoDB web interface, or use the cluster maintenance tools  (create-move-plan and execute-move-plan specifically). In the latter case, contact ArangoDB customer support.

    Number of leader shards not fully replicated

    arangodb_shards_out_of_sync

    Number of leader shards not fully replicated. This is counted for all shards for which this server is currently the leader. The number is increased by one for every shards for which not all followers are in sync.

    Introduced in: v3.7.1

    TypeUnitComplexityExposed by
    gaugenumbersimpleCoordinators, DB-Servers and Agents

    Troubleshoot: Needless to say, such a situation is not good resilience, since we do not have as many copies of the data as the replicationFactor prescribes. If this metrics has a value greater than 0, then some action is indicated. During an upgrade or when some DB-Server was restarted, it can happen that shard followers are out of sync. Normally, shards should get in sync on their own, so observation and waiting is a good measure at first. However, if the situation persists, something is wrong, potentially some constant server crash (maybe out of memory crashes?) or another situation preventing shards to get in sync. Contact ArangoDB customer support in this case.

    Number of times a follower shard needed to be completely rebuilt because of

    too many synchronization failures

    arangodb_sync_rebuilds_total

    Number of times a follower shard needed to be completely rebuilt because of too many subsequent shard synchronization failures. This metric is always zero from version 3.9.3 onwards. In previous releases, a non-zero value indicates that a follower shard could not get in sync with the leader even after many attempts. When the metric got increased, the follower shard was dropped and completely rebuilt from leader data, in order to increase its chances of getting in sync.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers and Single Servers

    Troubleshoot: This number is always 0 from version 3.9.3 onwards. If it is non-zero in previous versions, then something is wrong, please contact ArangoDB customer support in this case.

    Number of times the synchronization of a follower shard synchronization

    attempt ran into a timeout

    arangodb_sync_timeouts_total

    Number of times a follower shard synchronization attempt ran into the timeout controlled by the startup option --cluster.shard-synchronization-attempt-timeout. Running into this timeout is not an error. The timeout simply restricts individual shard synchronization attempts to a certain maximum runtime. When it happens, the shard synchronization attempt is aborted by the follower, but immediately retried afterwards. This abort-and-retry operation allows the leader DB-Servers to purge their archived WAL files for the aborted snapshots timely, so that long-running shard synchronization aborts do not lead to overly long WAL file retention periods on leaders.

    Introduced in: v3.9.2

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers

    Number of times a revision tree for a shard was completely

    rebuilt because of too many subsequent failures in the shard synchronization

    arangodb_sync_tree_rebuilds_total

    Number of times a revision tree for a shard was completely rebuilt because of too many subsequent failures in the shard synchronization. If shards cannot get in sync after several attempts, the shard’s revision tree is first rebuilt on the follower, and then on the leader. If the value is greater than zero, it means there have been shard synchronization failures.

    Introduced in: v3.10.6

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers and Single Servers

    Number of times a mismatching shard checksum was detected when syncing shards

    arangodb_sync_wrong_checksum_total

    Number of times a mismatching shard checksum was detected when syncing shards. This is a very special metric which is rarely used. When followers of shards get in sync with their leaders, just when everything is completed a final checksum is taken as an additional precaution. If this checksum differs between leader an follower, the incremental resync process starts from scratch.

    Introduced in: v3.8.0

    Renamed from: arangodb_sync_wrong_checksum

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers and Single Servers

    Troubleshoot: Normally, this number is always 0. If it is not, then usually something is wrong, please contact ArangoDB customer support in this case.

    Number of shards that are read-only due to an undercut of the write concern

    arangodb_vocbase_shards_read_only_by_write_concern

    Number of shards that are in read-only mode because there are not at least write concern many in-sync replicas.

    Introduced in: v3.12.1

    TypeUnitComplexityExposed by
    gaugenumbersimpleDB-Servers

    Troubleshoot: If this metrics has a value greater than 0, then some action is indicated. During an upgrade or when some DB-Server was restarted, it can happen that shard followers are out of sync and thus the write concern is undercut. Normally, shards should get in sync on their own, so observation and waiting is a good measure at first. However, if the situation persists, something is wrong, potentially some constant server crash (maybe out of memory crashes?) or another situation preventing shards to get in sync. Contact ArangoDB customer support in this case.

    RocksDB

    Collection lock acquisition time histogram

    arangodb_collection_lock_acquisition_time (basename)
    arangodb_collection_lock_acquisition_time_bucket
    arangodb_collection_lock_acquisition_time_sum
    arangodb_collection_lock_acquisition_time_count

    Histogram of the collection/shard lock acquisition times. Locks are acquired for all write operations, but not for read operations. The values here are measured in seconds.

    Introduced in: v3.6.11

    TypeUnitComplexityExposed by
    histogramsmediumDB-Servers, Agents and Single Servers

    Troubleshoot: In case these values are considered too high, check if there are AQL queries or transactions that use exclusive locks on collections, and try to reduce them. Operations using exclusive locks may lock out other queries/transactions temporarily, which leads to an increase in lock acquisition times.

    Number of currently active flush subscriptions

    arangodb_flush_subscriptions

    This metric exposes the number of currently active flush subscriptions. Flush subscriptions can be created by arangosearch View links and by background index creation.

    Introduced in: v3.9.10

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Number of times RocksDB has entered a stalled (slowed) write state

    arangodb_rocksdb_write_stalls_total

    This counter reflects the number of times RocksDB was observed by ArangoDB to have entered a stalled (slowed) write state.

    If the RocksDB background threads which do cleanup and compaction cannot keep up with the writing, then RocksDB first throttles its write rate (“write stall”) and later stops the writing entirely (“write stop”). Both are suboptimal, since the write rate is too high.

    Introduced in: v3.8.0

    Renamed from: rocksdb_write_stalls

    TypeUnitComplexityExposed by
    counternumbersimpleDB-Servers, Agents and Single Servers

    Threshold: If this number grows, you are probably writing faster to ArangoDB than RocksDB can keep up with its background processing. This is OK for a while, but might eventually lead to actual write stops, which are bad since they can lead to unavailability.

    Troubleshoot: Quite often, RocksDB is limited by the available I/O bandwidth. Sometimes, it is not the bandwidth itself, but the number of I/O operations per second (IOPS) which is limited. If you are in a cloud environment, IOPS are often scarce (or expensive) and you might be able to deploy more.

    Number of times RocksDB has entered a stopped write state

    arangodb_rocksdb_write_stops_total

    This counter reflects the number of times RocksDB was observed by ArangoDB to have entered a stopped write state.

    If the RocksDB background threads which do cleanup and compaction cannot keep up with the writing, then RocksDB first throttles its write rate (“write stall”) and later stops the writing entirely (“write stop”). Both are suboptimal, since the write rate is too high, but write stops are considerably worse, since they can lead to service unavailability.

    Introduced in: v3.8.0

    Renamed from: rocksdb_write_stops

    TypeUnitComplexityExposed by
    counternumbersimpleDB-Servers, Agents and Single Servers

    Threshold: If this number grows, you are probably writing a lot faster to ArangoDB than RocksDB can keep up with its background processing. This has lead to actual write stops, which are bad since they can lead to unavailability. If you see this number grow, you need to act, if in doubt, contact ArangoDB support.

    Troubleshoot: Quite often, RocksDB is limited by the available I/O bandwidth. Sometimes, it is not the bandwidth itself, but the number of I/O operations per second (IOPS) which is limited. If you are in a cloud environment, IOPS are often scarce (or expensive) and you might be able to deploy more.

    Actual delayed RocksDB write rate

    rocksdb_actual_delayed_write_rate

    This metric exhibits the RocksDB metric rocksdb-actual-delayed-write-rate. It shows the current actual delayed write rate. The value 0 means no delay.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Number of RocksDB WAL files in the archive

    rocksdb_archived_wal_files

    This metric exhibits the total number of RocksDB WAL files in the “archive” subdirectory. These are WAL files that can be garbage-collected eventually, when they are not used anymore by replication, WAL tailing or other purposes.

    Introduced in: v3.8.2

    TypeUnitComplexityExposed by
    gaugenumbermediumDB-Servers, Agents and Single Servers

    Cumulated size of RocksDB WAL files in the archive

    rocksdb_archived_wal_files_size

    This metric exhibits the cumulated size of RocksDB WAL files in the archive subdirectory on disk. These are WAL files that can be garbage-collected eventually, when they are not used anymore by replication, WAL tailing or other purposes.

    Introduced in: v3.9.11

    TypeUnitComplexityExposed by
    gaugebytesmediumDB-Servers, Agents and Single Servers

    Total number of RocksDB background errors

    rocksdb_background_errors

    This metric exhibits the RocksDB metric background-errors. It shows the accumulated number of background errors.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    RocksDB base level

    rocksdb_base_level

    This metric exhibits the RocksDB metric rocksdb-base-level. It shows the number of the level to which L0 data is compacted.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    RocksDB block cache capacity

    rocksdb_block_cache_capacity

    This metric exhibits the RocksDB metric rocksdb-block-cache-capacity. It shows the block cache capacity in bytes. This can be configured with the --rocksdb.block-cache-size startup option.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugebytesadvancedDB-Servers, Agents and Single Servers

    Size of pinned RocksDB block cache entries

    rocksdb_block_cache_pinned_usage

    This metric exhibits the RocksDB metric rocksdb-block-cache-pinned-usage. It shows the memory size for the RocksDB block cache for the entries which are pinned, in bytes.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugebytesadvancedDB-Servers, Agents and Single Servers

    Cumulated size of RocksDB block cache entries

    rocksdb_block_cache_usage

    This metric exhibits the RocksDB metric rocksdb-block-cache-usage. It shows the total memory size for the entries residing in the block cache, in bytes.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugebytesadvancedDB-Servers, Agents and Single Servers

    Global current number of hash tables in ArangoDB cache

    rocksdb_cache_active_tables

    This metric reflects the current number of active hash tables used by the in-memory cache which sits in front of RocksDB. Active tables are used for caching index entries. There should be one active table per index per shard for each index that has in-memory caching enabled. There can also be additional active tables while an existing hash table is migrated to a larger table.

    Introduced in: v3.10.0

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Global current memory allocation of ArangoDB in-memory caches

    rocksdb_cache_allocated

    This metric reflects the current global allocation for the ArangoDB in-memory cache which sits in front of RocksDB. For example, the edge caches counts towards this allocation. All these caches together have a global limit which can be controlled with the --cache.size startup option.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugebytesadvancedDB-Servers, Agents and Single Servers

    Total number of dropped entries in automatic in-memory index cache refilling

    rocksdb_cache_auto_refill_dropped_total

    This metric shows the total number of entries for which no automatic refilling happened in the in-memory index caches. This counter increases only for insert, update, replace, and remove operations affecting edge indexes and cache-enabled persistent indexes and with requested automatic refilling, if no refill operation could be queued due to capacity constraints. A refill operation request can be rejected if the number of currently queued refill operations exceeds the maximum value configured via the --rocksdb.auto-refill-index-cache-queue-capacity startup option. Correctness of index lookups is not affected if this metric is non-zero, as it only reports the number of failed refilling attempts in the in-memory caches of any index. These in-memory caches are optional and their fill grade does not affect correctness.

    Introduced in: v3.10.2

    TypeUnitComplexityExposed by
    counternumberadvancedCoordinators, DB-Servers, Agents and Single Servers

    Troubleshoot: If this metric keeps increasing, it indicates that the index refill background thread can’t keep up with the incoming data modification requests. In this case, consider increasing the background thread’s queueing capacity via the --rocksdb.auto-refill-index-cache-queue-capacity startup option. Increasing the capacity helps to handle bursts of request, but does not help if the background thread is overwhelmed by a continuous high load.

    Total number of automatically refilled in-memory index cache entries

    rocksdb_cache_auto_refill_loaded_total

    This metric shows the total number of automatically refilled in-memory index cache entries. Entries in the in-memory index caches are automatically refilled for edge indexes and cache-enabled persistent indexes if an insert, update, replace, or remove operation requests the cache refilling, or if the --rocksdb.auto-refill-index-caches startup option is enabled. On Agents and Coordinators, the values reported by this metric are always zero.

    Introduced in: v3.10.2

    TypeUnitComplexityExposed by
    counternumberadvancedCoordinators, DB-Servers, Agents and Single Servers

    Total number of in-memory index cache refill operations for a complete

    index

    rocksdb_cache_full_index_refills_total

    This metric shows the total number of refill operations to in-memory index caches for entire edge indexes and cache-enabled persistent indexes. On DB-Servers, a full index reload can increase this metric by more than one, as counting is done per shard. On Coordinators and Agents, this metric always contains a value of zero.

    Introduced in: v3.10.2

    TypeUnitComplexityExposed by
    counternumberadvancedCoordinators, DB-Servers, Agents and Single Servers

    Lifetime hit rate of the ArangoDB cache in front of RocksDB

    rocksdb_cache_hit_rate_lifetime

    This metric reflects the lifetime hit rate of the ArangoDB in-memory cache which is sitting in front of RocksDB. For example, the edge cache is a part of this. The value is a ratio between 0 and 1. “Lifetime” means here that accounting is done from the most recent start of the arangod instance. If the hit rate is too low, you might have to little RAM available for the in-memory caches.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugeratioadvancedDB-Servers, Agents and Single Servers

    Recent hit rate of the ArangoDB cache in front of RocksDB

    rocksdb_cache_hit_rate_recent

    This metric reflects the recent hit rate of the ArangoDB in-memory cache which is sitting in front of RocksDB. For example, the edge cache is a part of this. The value is a ratio between 0 and 1. If the hit rate is too low, you might have to little RAM available for the in-memory caches.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugeratioadvancedDB-Servers, Agents and Single Servers

    Global allocation limit for the ArangoDB cache in front of RocksDB

    rocksdb_cache_limit

    This metric reflects the current global allocation limit for the ArangoDB caches which sit in front of RocksDB. For example, the edge cache counts towards this allocation. This global limit can be controlled with the --cache.size startup option.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugebytesadvancedDB-Servers, Agents and Single Servers

    Global peak memory allocation of ArangoDB in-memory caches

    rocksdb_cache_peak_allocated

    This metric reflects the peak global allocation for the ArangoDB in-memory cache which sits in front of RocksDB. It records the peak value of the metric rocksdb_cache_allocated during the lifetime of the arangod instance.

    Introduced in: v3.10.7

    TypeUnitComplexityExposed by
    gaugebytesadvancedDB-Servers, Agents and Single Servers

    Global current memory allocation of inactive/reserve hash tables in ArangoDB cache

    rocksdb_cache_unused_memory

    This metric reflects the current memory allocation for unused hash tables used by the in-memory cache which sits in front of RocksDB. Unused tables can be kept as backups to provide new, readily initialized tables for new caches. The overall memory usage of unused tables is capped by the system, so it does not grow overly large.

    Introduced in: v3.10.0

    TypeUnitComplexityExposed by
    gaugebytesadvancedDB-Servers, Agents and Single Servers

    Global current number of inactive/reserve hash tables in ArangoDB cache

    rocksdb_cache_unused_tables

    This metric reflects the current number of unused hash tables used by the in-memory cache which sits in front of RocksDB. Unused tables can be kept as backups to provide new, readily initialized tables for new caches. Unused tables can consume some memory, but the overall memory usage of unused tables is capped.

    Introduced in: v3.10.0

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Number of RocksDB column families with pending compaction

    rocksdb_compaction_pending

    This metric exhibits the RocksDB metric compaction-pending. It shows the number of column families for which at least one compaction is pending.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    RocksDB compression ratio at level 0

    rocksdb_compression_ratio_at_level0

    This metric exhibits the compression ratio of data at level 0 in RocksDB’s log structured merge tree. Here, compression ratio is defined as uncompressed data size / compressed file size. Returns -1.0 if there are no open files at level 0.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugeratioadvancedDB-Servers, Agents and Single Servers

    RocksDB compression ratio at level 1

    rocksdb_compression_ratio_at_level1

    This metric exhibits the compression ratio of data at level 1 in RocksDB’s log structured merge tree. Here, compression ratio is defined as uncompressed data size / compressed file size. Returns -1.0 if there are no open files at level 1.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugeratioadvancedDB-Servers, Agents and Single Servers

    RocksDB compression ratio at level 2

    rocksdb_compression_ratio_at_level2

    This metric exhibits the compression ratio of data at level 2 in RocksDB’s log structured merge tree. Here, compression ratio is defined as uncompressed data size / compressed file size. Returns -1.0 if there are no open files at level 2.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugeratioadvancedDB-Servers, Agents and Single Servers

    RocksDB compression ratio at level 3

    rocksdb_compression_ratio_at_level3

    This metric exhibits the compression ratio of data at level 3 in RocksDB’s log structured merge tree. Here, compression ratio is defined as uncompressed data size / compressed file size. Returns -1.0 if there are no open files at level 3.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugeratioadvancedDB-Servers, Agents and Single Servers

    RocksDB compression ratio at level 4

    rocksdb_compression_ratio_at_level4

    This metric exhibits the compression ratio of data at level 4 in RocksDB’s log structured merge tree. Here, compression ratio is defined as uncompressed data size / compressed file size. Returns -1.0 if there are no open files at level 4.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugeratioadvancedDB-Servers, Agents and Single Servers

    RocksDB compression ratio at level 5

    rocksdb_compression_ratio_at_level5

    This metric exhibits the compression ratio of data at level 5 in RocksDB’s log structured merge tree. Here, compression ratio is defined as uncompressed data size / compressed file size. Returns -1.0 if there are no open files at level 5.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugeratioadvancedDB-Servers, Agents and Single Servers

    RocksDB compression ratio at level 6

    rocksdb_compression_ratio_at_level6

    This metric exhibits the compression ratio of data at level 6 in RocksDB’s log structured merge tree. Here, compression ratio is defined as uncompressed data size / compressed file size. Returns -1.0 if there are no open files at level 6.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugeratioadvancedDB-Servers, Agents and Single Servers

    Approximate size of RocksDB’s active memtable

    rocksdb_cur_size_active_mem_table

    This metric exhibits the RocksDB metric rocksdb-cur-size-active-mem-table. It shows the approximate size of the active memtable in bytes, summed over all column families.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugebytesadvancedDB-Servers, Agents and Single Servers

    Approximate size of all active and unflushed RocksDB memtables

    rocksdb_cur_size_all_mem_tables

    This metric exhibits the RocksDB metric rocksdb-cur-size-all-mem-tables. It shows the approximate size of active and unflushed immutable memtables in bytes, summed over all column families.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugebytesadvancedDB-Servers, Agents and Single Servers

    Current rate of the RocksDB throttle in bytes per second

    rocksdb_engine_throttle_bps

    This metric exposes the current write rate limit of the ArangoDB RocksDB throttle. The throttle limits the write rate to allow RocksDB’s background threads to catch up with compactions and not fall behind too much, since this would in the end lead to nasty write stops in RocksDB and incur considerable delays. If 0 is shown, no throttling happens, otherwise, you see the current write rate limit in bytes per second. Also see the --rocksdb.* startup options.

    Introduced in: v3.8.0

    Renamed from: rocksdbengine_throttle_bps

    TypeUnitComplexityExposed by
    gaugebytes per secondadvancedDB-Servers, Agents and Single Servers

    Estimated amount of live RocksDB data

    rocksdb_estimate_live_data_size

    This metric exhibits the RocksDB metric rocksdb-estimate-live-data-size. It shows an estimate of the amount of live data in bytes, summed over all column families.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugebytesadvancedDB-Servers, Agents and Single Servers

    Estimated number of RocksDB keys

    rocksdb_estimate_num_keys

    This metric exhibits the RocksDB metric rocksdb-estimate-num-keys. It shows the estimated number of total keys in the active and unflushed immutable memtables and storage, summed over all column families.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Estimated number of bytes awaiting RocksDB compaction

    rocksdb_estimate_pending_compaction_bytes

    This metric exhibits the RocksDB metric rocksdb-estimate-pending-compaction-bytes. It shows the estimated total number of bytes compaction needs to rewrite to get all levels down to under target size. Not valid for other compactions than level-based. This value is summed over all column families.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugebytesadvancedDB-Servers, Agents and Single Servers

    Estimated memory usage for reading RocksDB SST tables

    rocksdb_estimate_table_readers_mem

    This metric exhibits the RocksDB metric rocksdb-estimate-table-readers-mem. It shows the estimated memory used for reading SST tables, excluding memory used in block cache (e.g. filter and index blocks), summed over all column families.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugebytesadvancedDB-Servers, Agents and Single Servers

    Free disk space in bytes on volume used by RocksDB

    rocksdb_free_disk_space

    This metric shows the currently free disk space in bytes on the volume which is used by RocksDB. Since RocksDB does not like out of disk space scenarios, please make sure that there is enough free disk space available at all times! Note that this metric is only available/populated on some platforms.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    gaugebytesadvancedDB-Servers, Agents and Single Servers

    Number of free inodes on the volume used by RocksDB

    rocksdb_free_inodes

    This metric shows the currently free number of inodes on the disk volume used by RocksDB. Since RocksDB does not like out of disk space scenarios, please make sure that there is enough free inodes available at all times! Note that this metric is only available/populated on some platforms.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Whether RocksDB file deletion is enabled

    rocksdb_is_file_deletions_enabled

    This metric exhibits the RocksDB metric rocksdb-is-file-deletions-enabled. It shows 0 if deletion of obsolete files is enabled, and otherwise, it shows a non-zero number. Note that for ArangoDB, this is supposed to always return 1, since the deletion of obsolete WAL files is done from ArangoDB, externally to RocksDB.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Whether RocksDB writes are stopped

    rocksdb_is_write_stopped

    This metric exhibits the RocksDB metric rocksdb-is-write-stopped. It shows 1 if writing to RocksDB has been stopped, and otherwise 0. If 1 is shown, this usually means that there are too many uncompacted files and the RocksDB background threads have not managed to keep up with their compaction work. This situation should be avoided, since nasty delays in database operations are incurred. If in doubt, contact ArangoDB support.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Size of live RocksDB SST files

    rocksdb_live_sst_files_size

    This metric exhibits the RocksDB metric rocksdb-live-sst-files-size. It shows the total size in bytes of all SST files belonging to the latest LSM tree, summed over all column families.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugebytesadvancedDB-Servers, Agents and Single Servers

    Number of live RocksDB WAL files

    rocksdb_live_wal_files

    This metric exhibits the total number of live RocksDB WAL files. These are WAL files that cannot be garbage-collected until they are moved over to the archive.

    Introduced in: v3.9.10

    TypeUnitComplexityExposed by
    gaugenumbermediumDB-Servers, Agents and Single Servers

    Cumulated live RocksDB WAL files

    rocksdb_live_wal_files_size

    This metric exhibits the cumulated size of live RocksDB WAL files on disk. WAL files that cannot be garbage-collected until they are moved over to the archive.

    Introduced in: v3.9.11

    TypeUnitComplexityExposed by
    gaugebytesmediumDB-Servers, Agents and Single Servers

    Number of RocksDB column families awaiting memtable flush

    rocksdb_mem_table_flush_pending

    This metric exhibits the RocksDB metric mem-table-flush-pending. It shows the number of column families for which a memtable flush is pending.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Minimum number of RocksDB log files to keep

    rocksdb_min_log_number_to_keep

    This metric exhibits the RocksDB metric rocksdb-min-log-number-to-keep. It shows the minimum log number of the log files that should be kept.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Number of deletes in active RocksDB memtable

    rocksdb_num_deletes_active_mem_table

    This metric exhibits the RocksDB metric rocksdb-num-deletes-active-mem-table. It shows the total number of delete entries in the active memtable, summed over all column families.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Number of deletes in unflushed immutable RocksDB memtables

    rocksdb_num_deletes_imm_mem_tables

    This metric exhibits the RocksDB metric rocksdb-num-deletes-imm-mem-tables. It shows the total number of delete entries in the unflushed immutable memtables, summed over all column families.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Number of entries in the active RocksDB memtable

    rocksdb_num_entries_active_mem_table

    This metric exhibits the RocksDB metric rocksdb-num-entries-active-mem-table. It shows the total number of entries in the active memtable, summed over all column families.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Number of entries in unflushed immutable RocksDB memtables

    rocksdb_num_entries_imm_mem_tables

    This metric exhibits the RocksDB metric rocksdb-num-entries-imm-mem-tables. It shows the total number of entries in the unflushed immutable memtables, summed over all column families.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Number of RocksDB files at level 0

    rocksdb_num_files_at_level0

    This metric reports the number of files at level 0 in the log structured merge tree of RocksDB.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Number of RocksDB files at level 1

    rocksdb_num_files_at_level1

    This metric reports the number of files at level 1 in the log structured merge tree of RocksDB.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Number of RocksDB files at level 2

    rocksdb_num_files_at_level2

    This metric reports the number of files at level 2 in the log structured merge tree of RocksDB.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Number of RocksDB files at level 3

    rocksdb_num_files_at_level3

    This metric reports the number of files at level 3 in the log structured merge tree of RocksDB.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Number of RocksDB files at level 4

    rocksdb_num_files_at_level4

    This metric reports the number of files at level 4 in the log structured merge tree of RocksDB.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Number of RocksDB files at level 5

    rocksdb_num_files_at_level5

    This metric reports the number of files at level 5 in the log structured merge tree of RocksDB.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Number of RocksDB files at level 6

    rocksdb_num_files_at_level6

    This metric reports the number of files at level 6 in the log structured merge tree of RocksDB.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Number of unflushed immutable RocksDB memtables

    rocksdb_num_immutable_mem_table

    This metric exhibits the RocksDB metric num-immutable-mem-table, which shows the number of immutable memtables that have not yet been flushed. This value is the sum over all column families.

    Memtables are sorted tables of key/value pairs which begin to be built up in memory. At some stage they are closed and become immutable, and some time later they are flushed to disk.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Number of flushed immutable RocksDB memtables

    rocksdb_num_immutable_mem_table_flushed

    This metric exhibits the RocksDB metric num-immutable-mem-table-flushed, which shows the number of immutable memtables that have already been flushed. This value is the sum over all column families.

    Memtables are sorted tables of key/value pairs which begin to be built up in memory. At some stage they are closed and become immutable, and some time later they are flushed to disk.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Number of live RocksDB versions

    rocksdb_num_live_versions

    This metric exhibits the RocksDB metric rocksdb-num-live-versions. It shows the number of live versions. Version is an internal data structure. See version_set.h in the RocksDB source for details. More live versions often mean more SST files are held from being deleted, by iterators or unfinished compactions. This number is the number summed up over all column families.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Number of running RocksDB compactions

    rocksdb_num_running_compactions

    This metric exhibits the RocksDB metric rocksdb-num-running-compactions. It shows the number of currently running compactions.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Number of running RocksDB flushes

    rocksdb_num_running_flushes

    This metric exhibits the RocksDB metric rocksdb-num-running-flushes. It shows the number of currently running flushes.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Number of unreleased RocksDB snapshots

    rocksdb_num_snapshots

    This metric exhibits the RocksDB metric rocksdb-num-snapshots. It shows the number of unreleased snapshots of the database.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Timestamp of oldest unreleased RocksDB snapshot

    rocksdb_oldest_snapshot_time

    This metric exhibits the RocksDB metric rocksdb-oldest-snapshot-time. It shows a number representing the Unix timestamp of the oldest unreleased snapshot.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Number of prunable RocksDB WAL files in the archive

    rocksdb_prunable_wal_files

    This metric exhibits the total number of RocksDB WAL files in the “archive” subdirectory that can be pruned. These are WAL files that can be pruned by a background thread to reclaim disk space.

    Introduced in: v3.8.2

    TypeUnitComplexityExposed by
    gaugenumbermediumDB-Servers, Agents and Single Servers

    RocksDB metric “background-errors”

    rocksdb_read_only

    This metric indicates whether RocksDB currently is in read-only mode, due to a background error. If RocksDB is in read-only mode, this metric has a value of 1. When in read-only mode, all writes into RocksDB fail. When RocksDB is in normal operations mode, this metric has a value of 0.

    Introduced in: v3.8.1

    TypeUnitComplexityExposed by
    gaugenumbersimpleDB-Servers, Agents and Single Servers

    Troubleshoot: If this value is non-zero, it means that all write operations in RocksDB fail until the RocksDB background error is resolved. The arangod server logfile should show more details about the exact errors that are happening, so logs should be inspected first. RocksDB can set a background error when some I/O operation fails. This is often due to disk space usage issues, so often either freeing disk space or increasing the disk capacity help. Under some conditions, RocksDB can automatically resume from the background error and go back into normal operations. However, if the background error happens during certain RocksDB operations, it cannot resume operations automatically, so the instance needs a manual restart after the error condition is removed.

    Approximate size of all RocksDB memtables

    rocksdb_size_all_mem_tables

    This metric exhibits the RocksDB metric rocksdb-size-all-mem-tables. It shows the approximate size of all active, unflushed immutable, and pinned immutable memtables in bytes, summed over all column families.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugebytesadvancedDB-Servers, Agents and Single Servers

    Used disk space in bytes on volume used by RocksDB

    rocksdb_total_disk_space

    This metric shows the currently used disk space in bytes on the volume which is used by RocksDB. Since RocksDB does not like out of disk space scenarios, please make sure that there is enough free disk space available at all times! Note that this metric is only available/populated on some platforms.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    gaugebytesadvancedDB-Servers, Agents and Single Servers

    Number of used inodes on the volume used by RocksDB

    rocksdb_total_inodes

    This metric shows the currently used number of inodes on the disk volume used by RocksDB. Since RocksDB does not like out of disk space scenarios, please make sure that there are enough free inodes available at all times! Note that this metric is only available/populated on some platforms.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Total number of RocksDB sst files, aggregated over all levels

    rocksdb_total_sst_files

    This metric reports the number of sst files of the log structured merge tree of RocksDB, aggregated over all levels.

    Introduced in: v3.11.1

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Size of all RocksDB SST files

    rocksdb_total_sst_files_size

    This metric exhibits the RocksDB metric rocksdb-total-sst-files-size. It shows the total size in bytes of all SST files, summed over all column families.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugebytesadvancedDB-Servers, Agents and Single Servers

    Whether or not the pruning of archived RocksDB WAL files is currently

    activated

    rocksdb_wal_pruning_active

    This metric contains a value of 0 if the pruning of archived RocksDB WAL files is not activated, and 1 if it is activated. WAL file pruning is normally deactivated for the first few minutes after an instance is started, so that other instances in the cluster can start replicating from the instance before all archived WAL files are deleted. The value should flip from 0 to 1 a few minutes after server start.

    Introduced in: v3.8.2

    TypeUnitComplexityExposed by
    gaugenumbermediumDB-Servers, Agents and Single Servers

    Lower bound sequence number from which WAL files need to be kept because

    of external flushing needs

    rocksdb_wal_released_tick_flush

    This metric exposes the RocksDB WAL sequence number from which onwards WAL files have to be kept because the WAL data could be used by external flushing needs. WAL files with sequence numbers higher than this value are not garbage-collected. The candidates that can keep WAL files from being garbage-collected are arangosearch View links or inverted indexes that are still syncing data, and background index creation.

    Introduced in: v3.9.10

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Lower bound sequence number from which WAL files need to be kept because

    of replication

    rocksdb_wal_released_tick_replication

    This metric exposes the RocksDB WAL sequence number from which onwards WAL files have to kept in the archive because the WAL data could be used by the replication. WAL files with sequence numbers higher than this value are not garbage-collected.

    Introduced in: v3.9.10

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Current RocksDB WAL sequence number

    rocksdb_wal_sequence

    This metric exposes the current RocksDB WAL sequence number. Any write operations into the database increases the sequence number.

    Introduced in: v3.8.5

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    RocksDB sequence number until which the background sync thread

    has caught up

    rocksdb_wal_sequence_lower_bound

    This metric exposes the RocksDB WAL sequence number until which the ArangoDB background sync thread has fully caught up to. The value exposed here should be monotonically increasing and always progress if there are write operations executing.

    Introduced in: v3.8.2

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers, Agents and Single Servers

    Scheduler

    Total number of REST handler tasks created for the scheduler

    arangodb_scheduler_handler_tasks_created_total

    Total number of REST handler tasks that were created for execution via the scheduler. This counter is increased for each incoming request for which a REST handler mapping exists and that does not need to be forwarded to another Coordinator in the cluster.

    Introduced in: v3.8.2

    TypeUnitComplexityExposed by
    counternumberadvancedCoordinators, DB-Servers, Agents and Single Servers

    Time required to take an item from the high priority queue

    arangodb_scheduler_high_prio_dequeue_hist (basename)
    arangodb_scheduler_high_prio_dequeue_hist_bucket
    arangodb_scheduler_high_prio_dequeue_hist_sum
    arangodb_scheduler_high_prio_dequeue_hist_count

    This histogram provides the distribution of time required to take entries from the high priority queue, i.e., the amount of time the jobs were sitting in the queue. Long dequeue times indicate that the server is under heavy load and high priority jobs cannot be dequeued in a timely manner.

    Introduced in: v3.12.1

    TypeUnitComplexityExposed by
    histogramµsadvancedCoordinators, DB-Servers, Agents and Single Servers

    Current queue length of the high priority queue in the scheduler

    arangodb_scheduler_high_prio_queue_length

    The number of jobs currently queued on the scheduler’s high priority queue. The capacity of the high priority queue can be configured via the startup option --server.prio1-size.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    gaugenumbermediumCoordinators, DB-Servers, Agents and Single Servers

    Total number of jobs dequeued

    arangodb_scheduler_jobs_dequeued_total

    The total number of jobs dequeued from all scheduler queues. Calculating the difference between arangodb_scheduler_jobs_submitted_total and arangodb_scheduler_jobs_dequeued_total gives the total number of currently queued jobs. Calculating the difference between arangodb_scheduler_jobs_dequeued_total and arangodb_scheduler_jobs_done_total gives the number of jobs currently being processed.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    counternumberadvancedCoordinators, DB-Servers, Agents and Single Servers

    Total number of queue jobs done

    arangodb_scheduler_jobs_done_total

    The total number of queue jobs done. Calculating the difference between arangodb_scheduler_jobs_dequeued_total and arangodb_scheduler_jobs_done_total gives the total number of jobs currently being processed.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    gaugenumberadvancedCoordinators, DB-Servers, Agents and Single Servers

    Total number of jobs submitted to the scheduler

    arangodb_scheduler_jobs_submitted_total

    Total number of jobs submitted to the scheduler. Calculating the difference between arangodb_scheduler_jobs_submitted_total and arangodb_scheduler_jobs_dequeued_total gives the total number of currently queued jobs.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    gaugenumberadvancedCoordinators, DB-Servers, Agents and Single Servers

    Time required to take an item from the low priority queue

    arangodb_scheduler_low_prio_dequeue_hist (basename)
    arangodb_scheduler_low_prio_dequeue_hist_bucket
    arangodb_scheduler_low_prio_dequeue_hist_sum
    arangodb_scheduler_low_prio_dequeue_hist_count

    This histogram provides the distribution of time required to take entries from the low priority queue, i.e., the amount of time the jobs were sitting in the queue. Long dequeue times indicate that the server is under heavy load and low priority jobs cannot be dequeued in a timely manner.

    Introduced in: v3.12.1

    TypeUnitComplexityExposed by
    histogramµssimpleCoordinators, DB-Servers, Agents and Single Servers

    Last recorded dequeue time for a low priority queue item

    arangodb_scheduler_low_prio_queue_last_dequeue_time

    Last recorded dequeue time for a low priority queue item, i.e., the amount of time the job was sitting in the queue. If there is nothing to do for a long time, this metric is reset to zero. A large value for this metric indicates that the server is under heavy load and low priority jobs cannot be dequeued in a timely manner

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    gaugemssimpleCoordinators, DB-Servers, Agents and Single Servers

    Threshold: Normally this time should be clearly sub-second.

    Troubleshoot: If you see larger values here, in particular over a longer period of time, you should consider reducing the load of the server (if possible), scaling up (bigger machine) or scaling out (more Coordinators). Otherwise requests cannot be processed in a timely manner and you run the risk that the queue becomes full and requests are declined.

    Current queue length of the low priority queue in the scheduler

    arangodb_scheduler_low_prio_queue_length

    The number of jobs currently queued on the scheduler’s low priority queue. The capacity of the low priority queue can be configured via the startup option --server.maximal-queue-size.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    gaugenumbermediumCoordinators, DB-Servers, Agents and Single Servers

    Time required to take an item from the maintenance priority queue

    arangodb_scheduler_maintenance_prio_dequeue_hist (basename)
    arangodb_scheduler_maintenance_prio_dequeue_hist_bucket
    arangodb_scheduler_maintenance_prio_dequeue_hist_sum
    arangodb_scheduler_maintenance_prio_dequeue_hist_count

    This histogram provides the distribution of time required to take entries from the maintenance priority queue, i.e., the amount of time the jobs were sitting in the queue. Long dequeue times indicate that the server is under heavy load and maintenance jobs cannot be dequeued in a timely manner. Note that maintenance jobs are critical for the operation of the cluster, so it is important to keep these dequeue times low.

    Introduced in: v3.12.1

    TypeUnitComplexityExposed by
    histogramµsadvancedCoordinators, DB-Servers, Agents and Single Servers

    Current queue length of the maintenance priority queue in the scheduler

    arangodb_scheduler_maintenance_prio_queue_length

    The number of jobs currently queued on the scheduler’s maintenance priority queue. These are the jobs with the highest priority and are mainly used for cluster internal operations. The capacity of the maintenance priority queue can be configured via the startup option --server.scheduler-queue-size.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    gaugenumbermediumCoordinators, DB-Servers, Agents and Single Servers

    Time required to take an item from the medium priority queue

    arangodb_scheduler_medium_prio_dequeue_hist (basename)
    arangodb_scheduler_medium_prio_dequeue_hist_bucket
    arangodb_scheduler_medium_prio_dequeue_hist_sum
    arangodb_scheduler_medium_prio_dequeue_hist_count

    This histogram provides the distribution of time required to take entries from the medium priority queue, i.e., the amount of time the jobs were sitting in the queue. Long dequeue times indicate that the server is under heavy load and medium priority jobs cannot be dequeued in a timely manner.

    Introduced in: v3.12.1

    TypeUnitComplexityExposed by
    histogramµsadvancedCoordinators, DB-Servers, Agents and Single Servers

    Current queue length of the medium priority queue in the scheduler

    arangodb_scheduler_medium_prio_queue_length

    The number of jobs currently queued on the scheduler’s medium priority queue. The capacity of the medium priority queue can be configured via the startup option --server.prio2-size.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    gaugenumbermediumCoordinators, DB-Servers, Agents and Single Servers

    Number of awake worker threads

    arangodb_scheduler_num_awake_threads

    The number of worker threads currently working on some job or spinning while waiting for new work (i.e., not sleeping).

    Introduced in: v3.8.0

    Renamed from: arangodb_scheduler_awake_threads

    TypeUnitComplexityExposed by
    gaugenumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Current number of detached worker threads

    arangodb_scheduler_num_detached_threads

    The number of worker threads currently started and detached from the scheduler. Worker threads which perform potentially long running tasks like waiting for a lock can detach themselves from the scheduler to allow new scheduler threads to be started and avoid server blockage.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    gaugenumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Current number of worker threads

    arangodb_scheduler_num_worker_threads

    The number of worker threads currently started. This includes detached worker threads. Worker threads can be started and stopped dynamically based on the server load.

    Introduced in: v3.6.7

    TypeUnitComplexityExposed by
    gaugenumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Current number of working threads

    arangodb_scheduler_num_working_threads

    The current number of threads actually working on some job (i.e., not spinning while waiting for new work).

    Introduced in: v3.6.10

    TypeUnitComplexityExposed by
    gaugenumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Total number of ongoing RestHandlers coming from the low priority queue

    arangodb_scheduler_ongoing_low_prio

    Total number of low priority jobs currently being processed.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    gaugenumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Number of tasks dropped and not added to internal queue

    arangodb_scheduler_queue_full_failures_total

    Number of tasks dropped because the queue was already full. The queue capacities can be configured via the startup options --server.scheduler-queue-size, --server.prio1-size, --server.prio2-size and --server.maximal-queue-size.

    Introduced in: v3.8.0

    Renamed from: arangodb_scheduler_queue_full_failures

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Server’s internal queue length

    arangodb_scheduler_queue_length

    The total number of currently queued jobs in all queues.

    Introduced in: v3.6.7

    TypeUnitComplexityExposed by
    gaugenumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Number of bytes allocated for tasks in the scheduler queue

    arangodb_scheduler_queue_memory_usage

    Number of bytes allocated for tasks in the scheduler queue.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    gaugebytesadvancedCoordinators, DB-Servers, Agents and Single Servers

    Number of tasks/requests dropped and not added to internal queue

    due to the client-specified queue time requirements not being satisfiable

    arangodb_scheduler_queue_time_violations_total

    Number of tasks/requests dropped because the client-specified queue time requirements, as indicated by client applications in the x-arango-queue-time-seconds HTTP request header could not be satisfied by the receiving server instance. This happens when the actual time needed to queue/dequeue requests on the scheduler queue exceeds the maximum time value that the client has specified in the request. Whenever this happens, the client application gets an HTTP 412 error response back with error code 21004 (“queue time violated”). Although the metric is exposed on all instance types, it is likely always 0 on DB-Servers, simply because Coordinators do not forward the x-arango-queue-time-seconds when they send internal requests to DB-Servers.

    Introduced in: v3.9.0

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Approximate stack memory usage of worker threads

    arangodb_scheduler_stack_memory_usage

    Approximate stack memory usage of worker threads. Currently a hard-coded default value of 4MB is assumed per worker thread.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    gaugebytesadvancedCoordinators, DB-Servers, Agents and Single Servers

    Total accumulated number of scheduler threads started

    arangodb_scheduler_threads_started_total

    Total accumulated number of scheduler threads started. Worker threads can be started and stopped dynamically based on the server load.

    Introduced in: v3.8.0

    Renamed from: arangodb_scheduler_threads_started

    TypeUnitComplexityExposed by
    counternumbermediumCoordinators, DB-Servers, Agents and Single Servers

    Accumulated total number of scheduler threads stopped

    arangodb_scheduler_threads_stopped_total

    Total accumulated number of scheduler threads stopped. Worker threads can be started and stopped dynamically based on the server load.

    Introduced in: v3.8.0

    Renamed from: arangodb_scheduler_threads_stopped

    TypeUnitComplexityExposed by
    counternumbermediumCoordinators, DB-Servers, Agents and Single Servers

    Statistics

    Number of asynchronous functions that are currently active (are not yet resolved)

    arangodb_async_active_functions

    Number of asynchronous functions that are currently active (are not yet resolved).

    Introduced in: v3.12.3

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers

    Number of active threads that execute asynchronous functions

    arangodb_async_active_threads

    Number of active threads that execute asynchronous functions.

    Introduced in: v3.12.3

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers

    Number of all asynchronous functions that have been created so far

    arangodb_async_functions_total

    Number of all asynchronous functions that have been created so far.

    Introduced in: v3.12.3

    TypeUnitComplexityExposed by
    counternumberadvancedDB-Servers

    Number of asynchronous functions that are resolved and are waiting for their deletion in the next garbage collection run

    arangodb_async_ready_for_deletion_functions

    Number of asynchronous functions that are resolved and are waiting for their deletion in the next garbage collection run. If this number does not go back to zero at some point, we missed calling the garbage collection in a thread.

    Introduced in: v3.12.3

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers

    Number of registered threads that execute asynchronous functions

    arangodb_async_registered_threads

    Number of registered threads that execute asynchronous functions.

    Introduced in: v3.12.3

    TypeUnitComplexityExposed by
    gaugenumberadvancedDB-Servers

    Number of all threads created so far that execute asynchronous functions

    arangodb_async_threads_total

    Number of all threads created so far that execute asynchronous functions.

    Introduced in: v3.12.3

    TypeUnitComplexityExposed by
    counternumberadvancedDB-Servers

    Bytes received for requests

    arangodb_client_connection_statistics_bytes_received (basename)
    arangodb_client_connection_statistics_bytes_received_bucket
    arangodb_client_connection_statistics_bytes_received_sum
    arangodb_client_connection_statistics_bytes_received_count

    Histogram of the received request sizes in bytes.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    histogrambytessimpleCoordinators, DB-Servers, Agents and Single Servers

    Bytes sent for responses

    arangodb_client_connection_statistics_bytes_sent (basename)
    arangodb_client_connection_statistics_bytes_sent_bucket
    arangodb_client_connection_statistics_bytes_sent_sum
    arangodb_client_connection_statistics_bytes_sent_count

    Histogram of the sent response sizes in bytes

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    histogrambytessimpleCoordinators, DB-Servers, Agents and Single Servers

    The number of client connections that are currently open

    arangodb_client_connection_statistics_client_connections

    The number of client connections that are currently open.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Total connection time of a client

    arangodb_client_connection_statistics_connection_time (basename)
    arangodb_client_connection_statistics_connection_time_bucket
    arangodb_client_connection_statistics_connection_time_sum
    arangodb_client_connection_statistics_connection_time_count

    Histogram of the connection’s total lifetime, i.e., the time between the point when the connection was established until it was closed. Smaller numbers indicate that there is not a lot of load and/or that connections are not reused for multiple requests. Consider using keep-alive header or HTTP/2.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    histogramsadvancedCoordinators, DB-Servers, Agents and Single Servers

    I/O time needed to answer a request

    arangodb_client_connection_statistics_io_time (basename)
    arangodb_client_connection_statistics_io_time_bucket
    arangodb_client_connection_statistics_io_time_sum
    arangodb_client_connection_statistics_io_time_count

    Histogram of I/O times needed to answer a request. This includes the time required to read the incoming request as well as the time required to send the response.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    histogramnumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Queueing time needed for requests

    arangodb_client_connection_statistics_queue_time (basename)
    arangodb_client_connection_statistics_queue_time_bucket
    arangodb_client_connection_statistics_queue_time_sum
    arangodb_client_connection_statistics_queue_time_count

    Histogram of the time requests are spending on a queue waiting to be processed. The overwhelming majority of these times should be clearly sub-second.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    histogramssimpleCoordinators, DB-Servers, Agents and Single Servers

    Request time needed to answer a request

    arangodb_client_connection_statistics_request_time (basename)
    arangodb_client_connection_statistics_request_time_bucket
    arangodb_client_connection_statistics_request_time_sum
    arangodb_client_connection_statistics_request_time_count

    Histogram of the time required to actually process a request. This does not include the time required to read the incoming request, the time the request is sitting on the queue, or the time required to send the response.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    histogramssimpleCoordinators, DB-Servers, Agents and Single Servers

    Total time needed to answer a request

    arangodb_client_connection_statistics_total_time (basename)
    arangodb_client_connection_statistics_total_time_bucket
    arangodb_client_connection_statistics_total_time_sum
    arangodb_client_connection_statistics_total_time_count

    Histogram of the total times required to process a request. This includes the time required to read the incoming request, the time the request is sitting in the queue, the time to actually process the request, and the time required to send the response.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    histogramssimpleCoordinators, DB-Servers, Agents and Single Servers

    Bytes received for requests, only user traffic

    arangodb_client_user_connection_statistics_bytes_received (basename)
    arangodb_client_user_connection_statistics_bytes_received_bucket
    arangodb_client_user_connection_statistics_bytes_received_sum
    arangodb_client_user_connection_statistics_bytes_received_count

    Histogram of the received request sizes in bytes, only considering user traffic, i.e. traffic authenticated with a real user (or role).

    Introduced in: v3.10.2

    TypeUnitComplexityExposed by
    histogrambytessimpleCoordinators, DB-Servers, Agents and Single Servers

    Bytes sent for responses, only user traffic

    arangodb_client_user_connection_statistics_bytes_sent (basename)
    arangodb_client_user_connection_statistics_bytes_sent_bucket
    arangodb_client_user_connection_statistics_bytes_sent_sum
    arangodb_client_user_connection_statistics_bytes_sent_count

    Histogram of the sent response sizes in bytes, only user traffic, i.e. traffic that has been authenticated with a real user (or role).

    Introduced in: v3.10.2

    TypeUnitComplexityExposed by
    histogrambytessimpleCoordinators, DB-Servers, Agents and Single Servers

    Total memory usage of connection statistics

    arangodb_connection_statistics_memory_usage

    Total memory usage of connection statistics. If the startup option --server.statistics is set to true, then some connection statistics are built up in memory for every connection that is made to the arangod server. It is expected that the memory usage reported by this metric remains relatively constant over time. It should grow only when there are bursts of new connections. Some memory is pre-allocated at startup for higher efficiency. No memory will be allocated for connection statistics if the startup option is set to false.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    gaugebytesadvancedCoordinators, DB-Servers, Agents and Single Servers

    Number of file descriptors currently opened by the arangod process

    arangodb_file_descriptors_current

    Number of file descriptors currently opened by the arangod process. This will include regular files as well as sockets. The metric is only available on platforms that support it. As counting the number of file descriptors can be expensive and can have an impact on performance, the metric will only be updated in a controllable interval. The interval can be adjusted via the startup option --server.count-descriptors-interval. Shorter intervals mean more up-to-date count values, at the potential expense of more IO operations that are required for counting. It is possible to turn off counting of file descriptors by setting the interval to 0. In this case, the metric will report a value of 0.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    gaugenumbermediumAgents, Coordinators, DB-Servers and Single Servers

    System limit for the number of open file descriptors for the arangod process

    arangodb_file_descriptors_limit

    System limit for the number of open file descriptors for the arangod process. It is only available on platforms that support it. The limit is imposed by the operating system or system configuration. The value of this metric will remain constant for the entire lifetime of the process.

    Introduced in: v3.11.0

    TypeUnitComplexityExposed by
    gaugenumbermediumAgents, Coordinators, DB-Servers and Single Servers

    Number of asynchronously executed HTTP requests

    arangodb_http_request_statistics_async_requests_total

    This counter reflects the total number of asynchronous HTTP requests which have hit this particular instance of arangod. Asynchronous refers to the fact that the response is not sent with the HTTP response, but is rather queried separately using the /_api/jobs API.

    Note that this counter is ever growing during the lifetime of the arangod process. However, when the process is restarted, it starts from scratch. In the Grafana dashboards, it is usually visualized as a rate per second, averaged with a sliding window of a minute.

    Introduced in: v3.8.0

    Renamed from: arangodb_http_request_statistics_async_requests

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Threshold: This metrics reflects the performance of an instance in a certain way. Note that your mileage may vary according to available resources as well as to complexity of the requests the client sends.

    Number of HTTP DELETE requests

    arangodb_http_request_statistics_http_delete_requests_total

    This counter reflects the total number of HTTP DELETE requests which have hit this particular instance of arangod.

    Note that this counter is ever growing during the lifetime of the arangod process. However, when the process is restarted, it starts from scratch. In the Grafana dashboards, it is usually visualized as a rate per second, averaged with a sliding window of a minute.

    Introduced in: v3.8.0

    Renamed from: arangodb_http_request_statistics_http_delete_requests

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Threshold: This metrics reflects the performance of an instance in a certain way. Note that your mileage may vary according to available resources as well as to complexity of the requests the client sends.

    Number of HTTP GET requests

    arangodb_http_request_statistics_http_get_requests_total

    This counter reflects the total number of HTTP GET requests which have hit this particular instance of arangod.

    Note that this counter is ever growing during the lifetime of the arangod process. However, when the process is restarted, it starts from scratch. In the Grafana dashboards, it is usually visualized as a rate per second, averaged with a sliding window of a minute.

    Introduced in: v3.8.0

    Renamed from: arangodb_http_request_statistics_http_get_requests

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Threshold: This metrics reflects the performance of an instance in a certain way. Note that your mileage may vary according to available resources as well as to complexity of the requests the client sends.

    Number of HTTP HEAD requests

    arangodb_http_request_statistics_http_head_requests_total

    This counter reflects the total number of HTTP HEAD requests which have hit this particular instance of arangod.

    Note that this counter is ever growing during the lifetime of the arangod process. However, when the process is restarted, it starts from scratch. In the Grafana dashboards, it is usually visualized as a rate per second, averaged with a sliding window of a minute.

    Introduced in: v3.8.0

    Renamed from: arangodb_http_request_statistics_http_head_requests

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Threshold: This metrics reflects the performance of an instance in a certain way. Note that your mileage may vary according to available resources as well as to complexity of the requests the client sends.

    Number of HTTP OPTIONS requests

    arangodb_http_request_statistics_http_options_requests_total

    This counter reflects the total number of HTTP OPTIONS requests which have hit this particular instance of arangod.

    Note that this counter is ever growing during the lifetime of the arangod process. However, when the process is restarted, it starts from scratch. In the Grafana dashboards, it is usually visualized as a rate per second, averaged with a sliding window of a minute.

    Introduced in: v3.8.0

    Renamed from: arangodb_http_request_statistics_http_options_requests

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Threshold: This metrics reflects the performance of an instance in a certain way. Note that your mileage may vary according to available resources as well as to complexity of the requests the client sends.

    Number of HTTP PATCH requests

    arangodb_http_request_statistics_http_patch_requests_total

    This counter reflects the total number of HTTP PATCH requests which have hit this particular instance of arangod.

    Note that this counter is ever growing during the lifetime of the arangod process. However, when the process is restarted, it starts from scratch. In the Grafana dashboards, it is usually visualized as a rate per second, averaged with a sliding window of a minute.

    Introduced in: v3.8.0

    Renamed from: arangodb_http_request_statistics_http_patch_requests

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Threshold: This metrics reflects the performance of an instance in a certain way. Note that your mileage may vary according to available resources as well as to complexity of the requests the client sends.

    Number of HTTP POST requests

    arangodb_http_request_statistics_http_post_requests_total

    This counter reflects the total number of HTTP POST requests which have hit this particular instance of arangod.

    Note that this counter is ever growing during the lifetime of the arangod process. However, when the process is restarted, it starts from scratch. In the Grafana dashboards, it is usually visualized as a rate per second, averaged with a sliding window of a minute.

    Introduced in: v3.8.0

    Renamed from: arangodb_http_request_statistics_http_post_requests

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Threshold: This metrics reflects the performance of an instance in a certain way. Note that your mileage may vary according to available resources as well as to complexity of the requests the client sends.

    Number of HTTP PUT requests

    arangodb_http_request_statistics_http_put_requests_total

    This counter reflects the total number of HTTP PUT requests which have hit this particular instance of arangod.

    Note that this counter is ever growing during the lifetime of the arangod process. However, when the process is restarted, it starts from scratch. In the Grafana dashboards, it is usually visualized as a rate per second, averaged with a sliding window of a minute.

    Introduced in: v3.8.0

    Renamed from: arangodb_http_request_statistics_http_put_requests

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Threshold: This metrics reflects the performance of an instance in a certain way. Note that your mileage may vary according to available resources as well as to complexity of the requests the client sends.

    Number of other HTTP requests

    arangodb_http_request_statistics_other_http_requests_total

    This counter reflects the total number of HTTP other or ILLEGAL requests which have hit this particular instance of arangod. These are all requests, which are not one of the following: DELETE, GET, HEAD, POST, PUT, OPTIONS, PATCH.

    Note that this counter is ever growing during the lifetime of the arangod process. However, when the process is restarted, it starts from scratch. In the Grafana dashboards, it is usually visualized as a rate per second, averaged with a sliding window of a minute.

    Introduced in: v3.8.0

    Renamed from: arangodb_http_request_statistics_other_http_requests

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Threshold: This metrics reflects the performance of an instance in a certain way. Note that your mileage may vary according to available resources as well as to complexity of the requests the client sends.

    Total number of HTTP requests executed by superuser/JWT

    arangodb_http_request_statistics_superuser_requests_total

    This counter reflects the total number of HTTP requests that have been authenticated with the JWT superuser token, which have hit this particular instance of arangod.

    Note that this counter is ever growing during the lifetime of the arangod process. However, when the process is restarted, it starts from scratch. In the Grafana dashboards, it is usually visualized as a rate per second, averaged with a sliding window of a minute.

    Introduced in: v3.8.0

    Renamed from: arangodb_http_request_statistics_superuser_requests

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Threshold: This metrics reflects the performance of an instance in a certain way. Note that your mileage may vary according to available resources as well as to complexity of the requests the client sends.

    Total number of HTTP requests

    arangodb_http_request_statistics_total_requests_total

    This counter reflects the total number of HTTP requests which have hit this particular instance of arangod. Note that this counter is ever growing during the lifetime of the arangod process. However, when the process is restarted, it starts from scratch. In the Grafana dashboards, it is usually visualized as a rate per second, averaged with a sliding window of a minute.

    Introduced in: v3.8.0

    Renamed from: arangodb_http_request_statistics_total_requests

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Threshold: This metrics reflects the performance of an instance in a certain way. Note that your mileage may vary according to available resources as well as to complexity of the requests the client sends.

    Total number of HTTP requests executed by user clients

    arangodb_http_request_statistics_user_requests_total

    This counter reflects the total number of HTTP requests that have been authenticated for some user (as opposed to with the JWT superuser token), which have hit this particular instance of arangod.

    Note that this counter is ever growing during the lifetime of the arangod process. However, when the process is restarted, it starts from scratch. In the Grafana dashboards, it is usually visualized as a rate per second, averaged with a sliding window of a minute.

    Introduced in: v3.8.0

    Renamed from: arangodb_http_request_statistics_user_requests

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Threshold: This metrics reflects the performance of an instance in a certain way. Note that your mileage may vary according to available resources as well as to complexity of the requests the client sends.

    Total memory usage of all index selectivity estimates

    arangodb_index_estimates_memory_usage

    Total memory usage of all index selectivity estimates. The metric includes memory used for buffering index write operations that still have to be applied. Index selectivity estimates are used for edge indexes and persistent indexes. On Coordinators, this metric will always have a value of 0.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    gaugebytesmediumDB-Servers, Agents and Single Servers

    Troubleshoot: Persistent indexes can be created with selectivity estimates turned off to save a bit of memory and slightly improve index write performance.

    Number of intermediate commits performed in transactions

    arangodb_intermediate_commits_total

    Number of intermediate commits performed in transactions. An intermediate commit happens if a logical transaction needs to be split into multiple physical transaction because of the volume of data handled in the transaction. The thresholds for when to perform an intermediate commit can be controlled by startup options --rocksdb.intermediate-commit-count (number of write operations after which an intermediate commit is triggered) and --rocksdb.intermediate-commit-size (cumulated size of write operations after which an intermediate commit is triggered). The values can also be overridden for individual transactions. This metric was named arangodb_intermediate_commits in previous versions of ArangoDb.

    Introduced in: v3.8.0

    Renamed from: arangodb_intermediate_commits

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers and Single Servers

    Troubleshoot: If this value is non-zero, it doesn’t necessarily indicate a problem. It can happen for large transactions and large data-loading jobs. However, as modifications performed by intermediate commits are persisted and cannot simply be rolled back in memory, it should be monitored whether the intermediate commits only happen for operations where they are expected. If they also happen for operations that are supposed to be atomic, then the intermediate commit size and count parameters need to be adjusted, or larger operations should be broken up into smaller ones in the client application.

    Amount of memory spent in ClusterInfo

    arangodb_internal_cluster_info_memory_usage

    Amount of memory spent in ClusterInfo. ClusterInfo keeps all relevant information about servers and shard distribution. It grows with the size of servers, databases, collections/shards and indexes in the cluster.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    gaugebytehighCoordinators and DB-Servers

    Total number of dropped log messages

    arangodb_logger_messages_dropped_total

    Total number of log messages that were dropped by the logger.

    Log messages that are produced by worker threads are pushed into a log queue that is owned by a dedicated logger thread. This dedicated log thread is then responsible for writing the log messages out to disk or stdout asynchronously. As there can be many threads that produce log messages, but only one thread that consumes and logs messages from the log queue, it is possible that the log queue grows too large, potentially consuming a lot of memory to buffer all non-consumed log messages in RAM. In order to prevent the log queue from using too much memory, its size is bounded. The startup option --log.max-queued-entries controls the maximum size of the log queue. Whenever the log queue has reached its capacity limit and a log producer thread tries to push a log message to the log queue, the log message will be dropped. For every dropped log message this metric will be increased by one, so it becomes visible that log messages were dropped.

    Introduced in: v3.12.1

    TypeUnitComplexityExposed by
    counternumbersimpleAgents, Coordinators, DB-Servers and Single Servers

    Troubleshoot: In case this metric is greater than one, there is too much logging going on for the log thread to keep up with incoming log messages. There are two ways to counteract this. Either the log levels needed to be lowered (e.g. from “trace” to “debug” or from “debug” to “info”), or the maximum capacity of the log queue needs to be increased. This can be achieved by adjusting the value of the startup option --log.max-queued-entries to a higher value.

    Number of document reads which have been executed with dirty reads

    arangodb_potentially_dirty_document_reads_total

    This counter exposes the number of document reads (single or batch to shards in the cluster) which have been executed with “dirty reads”. A dirty read is one which may also use follower shards and not only leader shards. Note that it is the transaction in the context of which the read runs which determines, if dirty reads are allowed.

    Introduced in: v3.10.0

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators

    Number of major page faults

    arangodb_process_statistics_major_page_faults_total

    This figure contains the number of major faults the process has made which have required loading a memory page from disk.

    Introduced in: v3.8.0

    Renamed from: arangodb_process_statistics_major_page_faults

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Number of minor page faults

    arangodb_process_statistics_minor_page_faults_total

    The number of minor faults the process has made which have not required loading a memory page from disk.

    Introduced in: v3.8.0

    Renamed from: arangodb_process_statistics_minor_page_faults

    TypeUnitComplexityExposed by
    gaugenumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Number of threads

    arangodb_process_statistics_number_of_threads

    Number of threads in the arangod process.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Resident set size

    arangodb_process_statistics_resident_set_size

    The total size of the number of pages the process has in real memory. This is just the pages which count toward text, data, or stack space. This does not include pages which have not been demand-loaded in, or which are swapped out. The resident set size is reported in bytes.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugebytessimpleCoordinators, DB-Servers, Agents and Single Servers

    Resident set size as fraction of system memory

    arangodb_process_statistics_resident_set_size_percent

    The relative size of the number of pages the process has in real memory compared to system memory. This is just the pages which count toward text, data, or stack space. This does not include pages which have not been demand-loaded in, or which are swapped out. The value is a ratio between 0.00 and 1.00.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugenumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Threshold: This value can be consistently relatively high, even when not under load, due to different caches like the RocksDB block cache or the edge cache. There should be some safety margin left, so it should not get too close to 1.

    Process system time

    arangodb_process_statistics_system_time

    Amount of time that this process has been scheduled in kernel mode, measured in seconds.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugessimpleCoordinators, DB-Servers, Agents and Single Servers

    Threshold: This metric can vary significantly dependent on the workload. If the rate is consistently very high, it could be an indication of some problem.

    Process user time

    arangodb_process_statistics_user_time

    Amount of time that this process has been scheduled in user mode, measured in seconds.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugessimpleCoordinators, DB-Servers, Agents and Single Servers

    Threshold: This metric can vary significantly dependent on the workload. If the rate is consistently very high, it could be an indication of some problem.

    Virtual memory size

    arangodb_process_statistics_virtual_memory_size

    This figure contains the size of the virtual memory the process is using.

    Introduced in: v3.6.1

    TypeUnitComplexityExposed by
    gaugebytessimpleCoordinators, DB-Servers, Agents and Single Servers

    Body size in bytes for HTTP/1.1 requests

    arangodb_request_body_size_http1 (basename)
    arangodb_request_body_size_http1_bucket
    arangodb_request_body_size_http1_sum
    arangodb_request_body_size_http1_count

    Histogram of the body sizes of the received HTTP/1.1 requests in bytes. Note that this does not account for the header.

    Introduced in: v3.7.15

    TypeUnitComplexityExposed by
    histogrambytesmediumCoordinators, DB-Servers, Agents and Single Servers

    Body size in bytes for HTTP/2 requests

    arangodb_request_body_size_http2 (basename)
    arangodb_request_body_size_http2_bucket
    arangodb_request_body_size_http2_sum
    arangodb_request_body_size_http2_count

    Histogram of the body sizes of the received HTTP/2 requests in bytes. Note that this does not account for the header.

    Introduced in: v3.7.15

    TypeUnitComplexityExposed by
    histogrambytesmediumCoordinators, DB-Servers, Agents and Single Servers

    Total memory usage of request statistics

    arangodb_request_statistics_memory_usage

    Total memory usage of request statistics. If the startup option --server.statistics is set to true, then some request statistics are built up in memory for incoming requests. Some memory is pre-allocated at startup for higher efficiency. It is expected that the memory usage reported by this metric remains relatively constant over time. It should grow only when there are bursts of incoming requests. No memory will be allocated for request statistics if the startup option is set to false.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    gaugebytesadvancedCoordinators, DB-Servers, Agents and Single Servers

    Memory consumed by incoming, queued, and currently processed requests

    arangodb_requests_memory_usage

    Measures the amount of memory currently allocated for incoming, queued, and currently processed requests. The memory usage includes the size of the request headers and the request bodies. This includes the memory usage of requests that are currently queued in the server’s scheduler queue and that are waiting to be processed.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    gaugebyteshighCoordinators, DB-Servers, Agents and Single Servers

    Number of CPU cores visible to the arangod process

    arangodb_server_statistics_cpu_cores

    Number of CPU cores visible to the arangod process, unless the environment variable ARANGODB_OVERRIDE_DETECTED_NUMBER_OF_CORES is set. In that case, the environment variable’s value is reported.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    gaugenumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Percentage of time that the system CPUs have been idle

    arangodb_server_statistics_idle_percent

    Percentage of time that the system CPUs have been idle, as a value between 0 and 100, and as reported by the operating system. This metric is only reported on some operating systems.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    gaugepercentagesimpleCoordinators, DB-Servers, Agents and Single Servers

    Percentage of time that the system CPUs have been waiting for I/O

    arangodb_server_statistics_iowait_percent

    Percentage of time that the system CPUs have been waiting for I/O, as a value between 0 and 100, and as reported by the operating system. This metric is only reported on some operating systems.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    gaugepercentagesimpleCoordinators, DB-Servers, Agents and Single Servers

    Physical memory in bytes

    arangodb_server_statistics_physical_memory

    Physical memory of the system in bytes, as reported by the operating system unless the environment variable ARANGODB_OVERRIDE_DETECTED_TOTAL_MEMORY is set. In that case, the environment variable’s value is reported.

    Introduced in: v3.6.7

    TypeUnitComplexityExposed by
    gaugebytessimpleCoordinators, DB-Servers, Agents and Single Servers

    Number of seconds elapsed since server start

    arangodb_server_statistics_server_uptime_total

    Number of seconds elapsed since server start, including fractional seconds. This metric was named arangodb_server_statistics_server_uptime in previous versions of ArangoDB.

    Introduced in: v3.8.0

    Renamed from: arangodb_server_statistics_server_uptime

    TypeUnitComplexityExposed by
    counterssimpleCoordinators, DB-Servers, Agents and Single Servers

    Percentage of time that the system CPUs have spent in kernel mode

    arangodb_server_statistics_system_percent

    Percentage of time that the system CPUs have spent in kernel mode, as a value between 0 and 100, and as reported by the operating system. This metric is only reported on some operating systems.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    gaugepercentagesimpleCoordinators, DB-Servers, Agents and Single Servers

    Percentage of time that the system CPUs have spent in user mode

    arangodb_server_statistics_user_percent

    Percentage of time that the system CPUs have spent in user mode, as a value between 0 and 100, and as reported by the operating system. This metric is only reported on some operating systems.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    gaugepercentagesimpleCoordinators, DB-Servers, Agents and Single Servers

    Number of V8 contexts currently alive

    arangodb_v8_context_alive

    Number of V8 contexts currently alive. Normally, only Coordinators and single servers should have V8 contexts, for DB-Servers and Agents the value is always zero.

    Introduced in: v3.6.7

    TypeUnitComplexityExposed by
    gaugenumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Threshold: If this number is close to the maximum allowed number of V8 contexts, there might be a shortage. This can delay Foxx queries and AQL user defined functions. On the other hand, V8 contexts can use quite a lot of memory, so one should not have too many if RAM is scarce.

    Number of V8 contexts currently busy

    arangodb_v8_context_busy

    Number of V8 contexts currently busy, that means, they are currently working on some JavaScript task. Normally, only Coordinators and single servers should have V8 contexts, for DB-Servers and Agents the value is always zero.

    Introduced in: v3.6.7

    TypeUnitComplexityExposed by
    gaugenumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Threshold: If this number is close to the maximum allowed number of V8 contexts, there might be a shortage. This can delay Foxx queries and AQL user defined functions. On the other hand, V8 contexts can use quite a lot of memory, so one should not have too many if RAM is scarce.

    Number of V8 contexts currently dirty

    arangodb_v8_context_dirty

    This gauge reflects the number of V8 contexts that are currently dirty. A V8 context is dirty, if it has executed JavaScript for some time and is due for a garbage collection.

    Introduced in: v3.6.7

    TypeUnitComplexityExposed by
    gaugenumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Number of V8 contexts currently free

    arangodb_v8_context_free

    This gauge reflects the number of V8 contexts that are currently free. If this number drops to 0 there might be a shortage of V8 contexts.

    Introduced in: v3.6.7

    TypeUnitComplexityExposed by
    gaugenumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Maximum number of concurrent V8 contexts

    arangodb_v8_context_max

    This is the maximum number of concurrent V8 contexts. This is limited by a server option, since V8 contexts can use a lot of RAM. V8 contexts are created and destroyed as needed up to the limit shown in this metric.

    Introduced in: v3.6.7

    TypeUnitComplexityExposed by
    gaugenumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Minimum number of concurrent V8 contexts

    arangodb_v8_context_min

    This is the minimum number of concurrent V8 contexts. This is limited by a server option. V8 contexts are created and destroyed as needed but there are never fewer than the limit shown in this metric.

    Introduced in: v3.6.7

    TypeUnitComplexityExposed by
    gaugenumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Total number of compressed inserts into the in-memory edge cache

    rocksdb_cache_edge_compressed_inserts_total

    Total number of compressed inserts into the in-memory edge cache. This metric is increased whenever a payload value for the edge cache was compressed and then inserted.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    counternumberadvancedDB-Servers, Agents and Single Servers

    Overall effective compression ratio of all edge cache entries ever stored

    in the edge cache

    rocksdb_cache_edge_compression_ratio

    Overall effective compression ratio of all edge cache entries ever stored in the in-memory edge cache. The value should be 0 if compression is not used.

    Introduced in: v3.11.2

    TypeUnitComplexityExposed by
    gaugebytesadvancedDB-Servers, Agents and Single Servers

    Total number of insertions into the in-memory edge cache

    for non-connected edges

    rocksdb_cache_edge_empty_inserts_total

    Total number of insertions into the in-memory edge cache for edges that were not connected to other edges. In this case, the edge case will store the information that there are no connected edges.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    counternumberadvancedDB-Servers, Agents and Single Servers

    Total effective memory size of all edge cache entries ever stored in the edge cache

    rocksdb_cache_edge_inserts_effective_entries_size_total

    Total effective memory size of all edge cache data that were stored in the the edge cache of any collection/shard since the server start. The size is calculated after any potential compression, so the compression efficiency can be estimated by this metric by the size of the uncompressed edge cache entries. Note that this metric is incremented upon every edge cache insert attempt. It is increased also when data cannot be inserted into the cache (e.g. because the cache had no memory left). The metric is not decreased when data gets evicted from the cache.

    Introduced in: v3.11.2

    Renamed from: rocksdb_cache_edge_effective_entries_size

    TypeUnitComplexityExposed by
    counterbytesadvancedDB-Servers, Agents and Single Servers

    Total number of insertions into the in-memory edge cache.

    in the edge cache

    rocksdb_cache_edge_inserts_total

    Total number of insertions into the in-memory edge cache. This metric is increased whenever a value is inserted into the in-memory edge cache, regardless of whether the value was compressed or not.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    counternumberadvancedDB-Servers, Agents and Single Servers

    Total gross memory size of all edge cache entries ever stored in the edge cache

    rocksdb_cache_edge_inserts_uncompressed_entries_size_total

    Total gross memory size of all edge cache data that were stored in the edge cache of any collection/shard since the server start. The size is calculated before any potential compression. Note that this metric is incremented upon every cache insert attempt. It is increased also when data cannot be inserted into the cache (e.g. because the cache had no memory left). The metric is not decreased when data gets evicted from the cache.

    Introduced in: v3.11.2

    Renamed from: rocksdb_cache_edge_uncompressed_entries_size

    TypeUnitComplexityExposed by
    counterbytesadvancedDB-Servers, Agents and Single Servers

    Total amount of time spent in ‘free memory’ tasks of the in-memory

    cache subsystem

    rocksdb_cache_free_memory_tasks_duration_total

    Total amount of time spent inside ‘free memory’ tasks of the in-memory cache subsystem. ‘free memory’ tasks are scheduled by the cache subsystem to free up memory in existing cache hash tables.

    Introduced in: v3.10.11

    TypeUnitComplexityExposed by
    counterusadvancedDB-Servers, Agents and Single Servers

    Total number of ‘free memory’ tasks scheduled by the in-memory

    cache subsystem

    rocksdb_cache_free_memory_tasks_total

    Total number of ‘free memory’ tasks that were scheduled by the in-memory edge cache subsystem. This metric will be increased whenever the cache subsystem schedules a task to free up memory in one of the managed in-memory caches. It is expected to see this metric rising when the cache subsystem hits its global memory budget.

    Introduced in: v3.10.11

    TypeUnitComplexityExposed by
    counternumberadvancedDB-Servers, Agents and Single Servers

    Total amount of time spent in ‘migrate’ tasks of the in-memory

    cache subsystem

    rocksdb_cache_migrate_tasks_duration_total

    Total amount of time spent inside ‘migrate’ tasks of the in-memory cache subsystem. ‘migrate’ tasks are scheduled by the cache subsystem to migrate existing cache hash tables to a bigger or smaller table.

    Introduced in: v3.10.11

    TypeUnitComplexityExposed by
    counterusadvancedDB-Servers, Agents and Single Servers

    Total number of ‘migrate’ tasks scheduled by the in-memory

    cache subsystem

    rocksdb_cache_migrate_tasks_total

    Total number of ‘migrate’ tasks that were scheduled by the in-memory edge cache subsystem. This metric will be increased whenever the cache subsystem schedules a task to migrate an existing cache hash table to a bigger or smaller size.

    Introduced in: v3.10.11

    TypeUnitComplexityExposed by
    counternumberadvancedDB-Servers, Agents and Single Servers

    Transactions

    Number of read operation requests on leaders

    arangodb_collection_leader_reads_total

    This metric exposes the number of per-shard read operation requests on DB-Servers. It is increased by AQL queries and single-/multi-document read operations.

    An AQL query increases the counter exactly once for a shard that is involved in the query in read-only mode, regardless if and how many documents/edges the query actually reads from the shard. For shards that are accessed by an AQL query in read/write mode, only the write counter is increased.

    For every single- or multi-document read operation, the counter is increased exactly once for each shard that is affected by the operation, even if multiple documents are read from the same shard.

    This metric is not exposed by default. It is only present if the startup option --server.export-shard-usage-metrics is set to either enabled-per-shard or enabled-per-shard-per-user. With the former setting, the metric has different labels for each shard that was read from. With the latter setting, the metric has different labels for each combination of shard and user that accessed the shard. The metric is only exposed on DB servers and not on Coordinators or single servers.

    Note that internal operations, such as internal queries executed for statistics gathering, internal garbage collection, and TTL index cleanup are not counted in these metrics. Additionally, all requests that use the superuser JWT for authentication and that do not have a specific user set, are not counted. Requests are also only counted if they have an ArangoDB user associated with them, so that the cluster must also be running with authentication turned on.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    counternumberadvancedDB-Servers

    Number of write operation requests on leaders

    arangodb_collection_leader_writes_total

    This metric exposes the number of per-shard write operation requests on DB-Servers. It is increased by AQL queries and single-/multi-document write operations.

    An AQL query increases the counter exactly once for a shard that is involved in the query in write-only or read-write mode, regardless if and how many documents/edges are inserted or modified in the shard.

    For every single- or multi-document write operation, the counter is increased exactly once for each shard that is affected by the operation, even if multiple documents are inserted, modified, or removed from the same shard.

    For collection truncate operations, the counter is also increased exactly once for each shard affected by the truncate.

    This metric is not exposed by default. It is only present if the startup option --server.export-shard-usage-metrics is set to either enabled-per-shard or enabled-per-shard-per-user. With the former setting, the metric has different labels for each shard that was read from. With the latter setting, the metric has different labels for each combination of shard and user that accessed the shard. The metric is only exposed on DB servers and not on Coordinators or single servers.

    Note that internal operations, such as internal queries executed for statistics gathering, internal garbage collection, and TTL index cleanup are not counted in these metrics. Additionally, all requests that use the superuser JWT for authentication and that do not have a specific user set, are not counted. Requests are also only counted if they have an ArangoDB user associated with them, so that the cluster must also be running with authentication turned on.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    counternumberadvancedDB-Servers

    Total amount of collection lock acquisition time

    arangodb_collection_lock_acquisition_micros_total

    Total amount of time it took to acquire collection/shard locks for write operations, summed up for all collections/shards. Does not increase for any read operations. The value is measured in microseconds.

    Introduced in: v3.8.0

    Renamed from: arangodb_collection_lock_acquisition_micros

    TypeUnitComplexityExposed by
    counterusmediumDB-Servers, Agents and Single Servers

    Troubleshoot: In case this value is considered too high, check if there are AQL queries or transactions that use exclusive locks on collections, and try to reduce them. Operations using exclusive locks may lock out other queries/transactions temporarily, which leads to an increase in lock acquisition time.

    Number of transactions using sequential locking of collections to avoid deadlocking

    arangodb_collection_lock_sequential_mode_total

    Number of transactions using sequential locking of collections to avoid deadlocking. By default, a Coordinator tries to lock all shards of a collection in parallel. This approach is normally fast but can cause deadlocks with other transactions that lock the same shards in a different order. In case such a deadlock is detected, the Coordinator aborts the lock round and starts a new one that locks all shards in sequential order. This avoids deadlocks, but has a higher setup overhead.

    Introduced in: v3.8.0

    Renamed from: arangodb_collection_lock_sequential_mode

    TypeUnitComplexityExposed by
    counternumberadvancedCoordinators

    Troubleshoot: In case this value is increasing, check if there are AQL queries or transactions that use exclusive locks on collections, and try to reduce them. Operations using exclusive locks may lock out other queries/transactions temporarily, which can lead to (temporary) deadlocks in case the queries/transactions are run on multiple shards on different servers.

    Number of timeouts when trying to acquire collection exclusive locks

    arangodb_collection_lock_timeouts_exclusive_total

    Number of timeouts when trying to acquire collection exclusive locks. This counter increases whenever an exclusive collection lock cannot be acquired within the configured lock timeout.

    Introduced in: v3.8.0

    Renamed from: arangodb_collection_lock_timeouts_exclusive

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers, Agents and Single Servers

    Troubleshoot: In case this value is considered too high, check if there are AQL queries or transactions that use exclusive locks on collections, and try to reduce them. Operations using exclusive locks may lock out other queries/transactions temporarily, which can lead to other operations running into timeouts waiting for the same locks.

    Number of timeouts when trying to acquire collection write locks

    arangodb_collection_lock_timeouts_write_total

    Number of timeouts when trying to acquire collection write locks. This counter increases whenever a collection write lock cannot be acquired within the configured lock timeout. This can only happen if writes on a collection are locked out by other operations on the collection that use an exclusive lock. Writes are not locked out by other, non-exclusively locked writes.

    Introduced in: v3.8.0

    Renamed from: arangodb_collection_lock_timeouts_write

    TypeUnitComplexityExposed by
    counternumbermediumDB-Servers, Agents and Single Servers

    Troubleshoot: In case this value is considered too high, check if there are AQL queries or transactions that use exclusive locks on collections, and try to reduce them. Operations using exclusive locks may lock out other queries/transactions temporarily, which can lead to other operations running into timeouts waiting for the same locks.

    Number of bytes read in read requests on DB-Servers

    arangodb_collection_requests_bytes_read_total

    This metric exposes the per-shard number of bytes read by read operation requests on DB-Servers. It is increased by AQL queries that read documents or edges and for single- or multi-document read operations. The metric is normally increased only on the leader, but it can also increase on followers if “reads from followers” are enabled.

    For every read operation, the metric is increased by the approximate number of bytes read to retrieve the underlying document or edge data. This is also true if a document or edge is served from an in-memory cache. If an operation reads multiple documents/edges, it increases the counter multiple times, each time with the approximate number of bytes read for the particular document/edge.

    The numbers reported by this metric normally relate to the cumulated sizes of documents/edges read. The metric is also increased for transactions that are started but later aborted. However, metrics updates may be buffered until the end of a transaction. Note that the metric is not increased for secondary index point lookups or scans, or for scans in a collection that iterate over documents but do not read them.

    This metric is not exposed by default. It is only present if the startup option --server.export-shard-usage-metrics is set to either enabled-per-shard or enabled-per-shard-per-user. With the former setting, the metric has different labels for each shard that was read from. With the latter setting, the metric has different labels for each combination of shard and user that accessed the shard. The metric is only exposed on DB servers and not on Coordinators or single servers.

    Note that internal operations, such as internal queries executed for statistics gathering, internal garbage collection, and TTL index cleanup are not counted in these metrics. Additionally, all requests that use the superuser JWT for authentication and that do not have a specific user set, are not counted. Requests are also only counted if they have an ArangoDB user associated with them, so that the cluster must also be running with authentication turned on.

    Enabling this metric via the startup option will likely result in a small latency overhead of few percent for read operations. The exact overhead depends on several factors, such as the type of operation (single or multi-document operation), replication factor, network latency etc.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    counternumberadvancedDB-Servers

    Number of bytes written in write requests on DB-Servers

    arangodb_collection_requests_bytes_written_total

    This metric exposes the per-shard number of bytes written by write operation requests on DB-Servers, on both leaders and followers. It is increased by AQL queries and single-/multi-document write operations. The metric is first increased only the leader. With traditional replication, the metric is also increased on followers for every replication request that the leader make to the followers. With the new replication protocol (“replication2”), the metric is not increased on followers.

    For every write operation, the metric is increased by the approximate number of bytes written for the document or edge in question. If an operation writes multiple documents/edges, it increases the counter multiple times, each time with the approximate number of bytes written for the particular document/edge.

    An AQL query also increases the counter for every document or edge written, each time with the approximate number of bytes written for document/edge.

    The numbers reported by this metric normally relate to the cumulated sizes of documents/edges written. For remove operations, however, only a fixed number of bytes is counted per removed document/edge. For truncate operations, the metrics will be affected differently depending on how the truncate is executed internally. For truncates on smaller shards, the truncate operation will be executed as the removal of the individual documents in the shard. Thus the metric will also be increased as if the documents were removed individually. Truncate operations on larger shards however will be executed via a special operation in the storage engine, which marks a whole range of documents as removed, but defers the actual removal until much later (compaction process). If a truncate is executed like this, the metric will not be increased at all. Writes into secondary indexes are not counted at all. The metric is also increased for transactions that are started but later aborted. However, metrics updates may be buffered until the end of a transaction.

    This metric is not exposed by default. It is only present if the startup option --server.export-shard-usage-metrics is set to either enabled-per-shard or enabled-per-shard-per-user. With the former setting, the metric has different labels for each shard that was read from. With the latter setting, the metric has different labels for each combination of shard and user that accessed the shard. The metric is only exposed on DB servers and not on Coordinators or single servers.

    Note that internal operations, such as internal queries executed for statistics gathering, internal garbage collection, and TTL index cleanup are not counted in these metrics. Additionally, all requests that use the superuser JWT for authentication and that do not have a specific user set, are not counted. Requests are also only counted if they have an ArangoDB user associated with them, so that the cluster must also be running with authentication turned on.

    Enabling this metric via the startup option will likely result in a small latency overhead of few percent for write operations. The exact overhead depends on several factors, such as the type of operation (single or multi-document operation), replication factor, network latency etc.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    counternumberadvancedDB-Servers

    Total time spent in collection truncate operations

    arangodb_collection_truncate_time (basename)
    arangodb_collection_truncate_time_bucket
    arangodb_collection_truncate_time_sum
    arangodb_collection_truncate_time_count

    Total time spent in collection truncate operations, including both user-initiated truncate operations and truncate operations executed by the synchronous replication on followers. Note that this metric is only present when the command line option --server.export-read-write-metrics is set to true.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    histogramssimpleDB-Servers, Agents and Single Servers

    Total number of collection truncate operations (excluding synchronous replication)

    arangodb_collection_truncates_total

    Total number of collection truncate operations on leaders (excluding synchronous replication). Note that this metric is only present when the command line option --server.export-read-write-metrics is set to true.

    Introduced in: v3.8.0

    Renamed from: arangodb_collection_truncates

    TypeUnitComplexityExposed by
    counternumbersimpleAgents, DB-Servers and Single Servers

    Number of read transactions, which are allowed to do dirty reads

    arangodb_dirty_read_transactions_total

    Total number of read-only transactions, which allow for dirty reads (read from followers). This metric is only collected for transactions on Coordinators in a cluster. Other instances may expose the value as 0.

    Introduced in: v3.10.0

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Total time spent in document insert operations

    arangodb_document_insert_time (basename)
    arangodb_document_insert_time_bucket
    arangodb_document_insert_time_sum
    arangodb_document_insert_time_count

    Total time spent in document insert operations, including both user-initiated insert operations and insert operations executed by the synchronous replication on followers. This metric is only present if the option --server.export-read-write-metrics is set to true.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    histogramssimpleAgents, DB-Servers and Single Servers

    Total time spent in document read-by-primary-key operations

    arangodb_document_read_time (basename)
    arangodb_document_read_time_bucket
    arangodb_document_read_time_sum
    arangodb_document_read_time_count

    Total time spent in document read-by-primary-key operations. This metric is only present if the option --server.export-read-write-metrics is set to true.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    histogramssimpleDB-Servers, Single Servers and Agents

    Total time spent in document remove operations

    arangodb_document_remove_time (basename)
    arangodb_document_remove_time_bucket
    arangodb_document_remove_time_sum
    arangodb_document_remove_time_count

    Total time spent in document replace operations, including both user-initiated replace operations and replace operations executed by the synchronous replication on followers. This metric is only present if the option --server.export-read-write-metrics is set to true.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    histogramssimpleAgents, DB-Servers and Single Servers

    Total time spent in document replace operations

    arangodb_document_replace_time (basename)
    arangodb_document_replace_time_bucket
    arangodb_document_replace_time_sum
    arangodb_document_replace_time_count

    Total time spent in document replace operations, including both user-initiated replace operations and replace operations executed by the synchronous replication on followers. This metric is only present if the option --server.export-read-write-metrics is set to true.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    histogramssimpleAgents, DB-Servers and Single Servers

    Total time spent in document update operations

    arangodb_document_update_time (basename)
    arangodb_document_update_time_bucket
    arangodb_document_update_time_sum
    arangodb_document_update_time_count

    Total time spent in document update operations, including both user-initiated update operations and update operations executed by the synchronous replication on followers. This metric is only present if the option --server.export-read-write-metrics is set to true.

    Introduced in: v3.8.0

    TypeUnitComplexityExposed by
    histogramssimpleAgents, DB-Servers and Single Servers

    Total number of document write operations (excluding synchronous replication)

    arangodb_document_writes_total

    Total number of document write operations (insert, update, replace, remove) on leaders, excluding writes by the synchronous replication on followers. This metric is only present if the option --server.export-read-write-metrics is set to true.

    Introduced in: v3.8.0

    Renamed from: arangodb_document_writes

    TypeUnitComplexityExposed by
    counternumbermediumAgents, DB-Servers and Single Servers

    Number of read transactions

    arangodb_read_transactions_total

    Total number of read-only transactions. In the cluster, this metric is collected separately for transactions on Coordinators and the transaction counterparts on leaders and followers.

    Introduced in: v3.8.2

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Number of transactions aborted

    arangodb_transactions_aborted_total

    Total number of transactions aborted. In the cluster, this metric is collected separately for transactions on Coordinators and the transaction counterparts on leaders and followers. This metric was named arangodb_transactions_aborted in previous versions of ArangoDB.

    Introduced in: v3.8.0

    Renamed from: arangodb_transactions_aborted

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Number of transactions committed

    arangodb_transactions_committed_total

    Total number of transactions committed. In the cluster, this metric is collected separately for transactions on Coordinators and the transaction counterparts on leaders and followers. This metric was named arangodb_transactions_committed in previous versions of ArangoDB.

    Introduced in: v3.8.0

    Renamed from: arangodb_transactions_committed

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Total number of expired transactions

    arangodb_transactions_expired_total

    Total number of expired transactions, i.e. transactions that have been begun but that were automatically garbage-collected due to inactivity within the transactions’ time-to-live (TTL) period. In the cluster, this metric is collected separately for transactions on Coordinators and the transaction counterparts on leaders and followers. This metric was named arangodb_transactions_expired in previous versions of ArangoDB.

    Introduced in: v3.8.0

    Renamed from: arangodb_transactions_expired

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Total memory usage of internal transactions

    arangodb_transactions_internal_memory_usage

    Total memory usage of currently ongoing internal transactions, i.e. transactions that were not explicitly started by an end user. Internal transactions include ArangoDB-internal maintenance queries, queries to purge data from TTL indexes, periodic queries for collecting and aggregating statistics, for maintaining the state of Foxx, and transactions internally used by shard synchronization.

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    gaugebytessimpleCoordinators, DB-Servers, Agents and Single Servers

    Total memory usage of user transactions (excluding top-level AQL queries)

    arangodb_transactions_rest_memory_usage

    This metric reflects the current amount of memory in bytes consumed by user-originated transactions in arangod. These are either streaming transactions, JavaScript transactions, or single-document/multi-document operations outside of a transaction. The metric includes the memory used for index creation operations. Top-level AQL queries are excluded from it, as they have their own metric (arangodb_aql_global_memory_usage).

    Introduced in: v3.12.0

    TypeUnitComplexityExposed by
    gaugebytessimpleCoordinators, DB-Servers, Agents and Single Servers

    Number of transactions started

    arangodb_transactions_started_total

    Total number of transactions started/begun. In the cluster, this metric is collected separately for transactions on Coordinators and the transaction counterparts on leaders and followers. This metric was named arangodb_transactions_started in previous versions of ArangoDB.

    Introduced in: v3.8.0

    Renamed from: arangodb_transactions_started

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    V8

    Total number of V8 contexts ever created

    arangodb_v8_context_created_total

    This counter reflects the total number of V8 contexts ever created. It is OK if this number keeps growing since the V8 contexts are created and destroyed as needed. In rare cases a high fluctuation can indicate some unfortunate usage pattern.

    Introduced in: v3.8.0

    Renamed from: arangodb_v8_context_created

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Accumulated total time for creating V8 contexts

    arangodb_v8_context_creation_time_msec_total

    This counter reflects the accumulated total time for creating V8 contexts, in milliseconds. It is OK if this number keeps growing since the V8 contexts are created and destroyed as needed. In rare cases a high fluctuation can indicate some unfortunate usage pattern.

    Introduced in: v3.8.0

    Renamed from: arangodb_v8_context_creation_time_msec

    TypeUnitComplexityExposed by
    countermsmediumCoordinators, DB-Servers, Agents and Single Servers

    Total number of V8 contexts ever destroyed

    arangodb_v8_context_destroyed_total

    This counter reflects the total number of V8 contexts ever destroyed. It is OK if this number keeps growing since the V8 contexts are created and destroyed as needed. In rare cases a high fluctuation can indicate some unfortunate usage pattern.

    Introduced in: v3.8.0

    Renamed from: arangodb_v8_context_destroyed

    TypeUnitComplexityExposed by
    counternumbermediumCoordinators, DB-Servers, Agents and Single Servers

    Total number of V8 context enter failures

    arangodb_v8_context_enter_failures_total

    Total number of V8 context enter failures. A context receives a context enter event every time it begins to execute some JavaScript. If no context is available at such a time the system waits for 60s for a context to become free. If this does not happen within the 60s, the context enter event fails, a warning is logged and this counter is increased by one.

    Introduced in: v3.8.0

    Renamed from: arangodb_v8_context_enter_failures

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Threshold: If you see V8 context enter failures, then you do not have enough V8 contexts or the server is overloaded by JavaScript tasks. If some JavaScript code blocks V8 contexts for too long, the free V8 contexts can run out and these failures begin to happen.

    Total number of V8 context enter events

    arangodb_v8_context_entered_total

    Total number of V8 context enter events. A context receives a context enter event every time it begins to execute some JavaScript. This number is a rough estimate as to how much JavaScript the server executes.

    Introduced in: v3.8.0

    Renamed from: arangodb_v8_context_entered

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Total number of V8 context exit events

    arangodb_v8_context_exited_total

    This counter reflects the total number of V8 context exit events. A context receives a context exit event every time it finishes to execute some JavaScript.

    Introduced in: v3.8.0

    Renamed from: arangodb_v8_context_exited

    TypeUnitComplexityExposed by
    counternumbersimpleCoordinators, DB-Servers, Agents and Single Servers

    Get usage metrics

    GET /_db/{database-name}/_admin/usage-metrics

    Returns detailed shard usage metrics on DB-Servers.

    These metrics can be enabled by setting the --server.export-shard-usage-metrics startup option to enabled-per-shard to make DB-Servers collect per-shard usage metrics, or to enabled-per-shard-per-user to make DB-Servers collect usage metrics per shard and per user whenever a shard is accessed.

    Path Parameters

    • The name of a database. Which database you use doesn’t matter as long as the user account you authenticate with has at least read access to this database. If the --server.harden startup option is enabled, administrate access to the _system database is required.

    Query Parameters

    • Returns the usage metrics of the specified server. If no serverId is given, the asked server will reply. This parameter is only meaningful on Coordinators.

    HTTP Headers
      Responses

      • Metrics were returned successfully.

      Metrics API

      Get the metrics (deprecated)

      GET /_db/{database-name}/_admin/metrics
      This endpoint should no longer be used. It is deprecated from version 3.8.0 on. Use /_admin/metrics/v2 instead. From version 3.10.0 onward, /_admin/metrics returns the same metrics as /_admin/metrics/v2.

      Returns the instance’s current metrics in Prometheus format. The returned document collects all instance metrics, which are measured at any given time and exposes them for collection by Prometheus.

      The document contains different metrics and metrics groups dependent on the role of the queried instance. All exported metrics are published with the arangodb_ or rocksdb_ string to distinguish them from other collected data.

      The API then needs to be added to the Prometheus configuration file for collection.

      Path Parameters

      • The name of a database. Which database you use doesn’t matter as long as the user account you authenticate with has at least read access to this database. If the --server.harden startup option is enabled, administrate access to the _system database is required.

      Query Parameters

      • Returns metrics of the specified server. If no serverId is given, the asked server will reply. This parameter is only meaningful on Coordinators.

      HTTP Headers
        Responses

        • Metrics were returned successfully.

        • The metrics API may be disabled using --server.export-metrics-api false setting in the server. In this case, the result of the call indicates the API to be not found.

        Examples

        curl --header 'accept: application/json' --dump - 'http://localhost:8529/_admin/metrics'
        Show output

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