ArangoDB v3.10 reached End of Life (EOL) and is no longer supported.

This documentation is outdated. Please see the most recent stable version.

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.

Metrics API v2

Get the metrics

GET /_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
    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

      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. Note that on single servers this metric only has a non-zero value in the Active Failover deployment mode.

      Introduced in: v3.8.0

      Renamed from: arangodb_agency_cache_callback_count

      TypeUnitComplexityExposed by
      gaugenumberadvancedDB-Servers, Coordinators and Single Servers

      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. Note that on single servers this metric only has a non-zero value in the Active Failover deployment mode.

      Introduced in: v3.8.0

      Renamed from: arangodb_agency_callback_count

      TypeUnitComplexityExposed by
      gaugenumberadvancedCoordinators, DB-Servers and Single 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. Note that on single servers this metric only has a non-zero value in the Active Failover deployment mode.

      Introduced in: v3.8.0

      Renamed from: arangodb_agency_callback_registered

      TypeUnitComplexityExposed by
      counternumberadvancedCoordinators, DB-Servers and Single 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

      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

      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

      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 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

      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

      Total number of VST connections accepted

      arangodb_vst_connections_total

      Total number of connections accepted for VST, this are upgraded connections from HTTP/1.1.

      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. In the single server, this counter is only used in the Active Failover deployment mode.

      Introduced in: v3.8.0

      Renamed from: arangodb_heartbeat_failures

      TypeUnitComplexityExposed by
      counternumbersimpleCoordinators, DB-Servers and Single 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. In the single server, this counter is only used in the Active Failover deployment mode.

      Introduced in: v3.7.1

      TypeUnitComplexityExposed by
      histogrammsmediumCoordinators, DB-Servers and Single 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.


      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.


      Pregel

      Number of loading Pregel conductors

      arangodb_pregel_conductors_loading_number

      Number of loading Pregel conductors.

      Introduced in: v3.10.0

      TypeUnitComplexityExposed by
      gaugenumbersimpleDB-Servers, Single Servers and Coordinators

      Number of Pregel conductors

      arangodb_pregel_conductors_number

      Number of Pregel conductors.

      Introduced in: v3.10.0

      TypeUnitComplexityExposed by
      gaugenumbersimpleDB-Servers, Single Servers and Coordinators

      Number of running Pregel conductors

      arangodb_pregel_conductors_running_number

      Number of running Pregel conductors.

      Introduced in: v3.10.0

      TypeUnitComplexityExposed by
      gaugenumbersimpleDB-Servers, Single Servers and Coordinators

      Number of storing Pregel conductors

      arangodb_pregel_conductors_storing_number

      Number of storing Pregel conductors.

      Introduced in: v3.10.0

      TypeUnitComplexityExposed by
      gaugenumbersimpleDB-Servers, Single Servers and Coordinators

      Memory allocated by Pregel for graph storage

      arangodb_pregel_graph_memory_bytes_number

      The number of bytes allocated by Pregel.

      Introduced in: v3.10.0

      TypeUnitComplexityExposed by
      gaugebytessimpleDB-Servers, Single Servers and Coordinators

      Number of messages received by Pregel

      arangodb_pregel_messages_received_total

      The number of messages received by Pregel.

      Introduced in: v3.10.0

      TypeUnitComplexityExposed by
      gaugenumbersimpleDB-Servers, Single Servers and Coordinators

      Number of messages sent by Pregel

      arangodb_pregel_messages_sent_total

      Number of messages sent by Pregel.

      Introduced in: v3.10.0

      TypeUnitComplexityExposed by
      gaugenumbersimpleDB-Servers, Single Servers and Coordinators

      Number of threads running for Pregel

      arangodb_pregel_threads_number

      Number of threads running for Pregel.

      Introduced in: v3.10.0

      TypeUnitComplexityExposed by
      gaugenumbersimpleDB-Servers, Single Servers and Coordinators

      Number of loading Pregel workers

      arangodb_pregel_workers_loading_number

      Number of loading Pregel workers.

      Introduced in: v3.10.0

      TypeUnitComplexityExposed by
      gaugenumbersimpleDB-Servers, Single Servers and Coordinators

      Number of Pregel workers

      arangodb_pregel_workers_number

      Number of Pregel Workers.

      Introduced in: v3.10.0

      TypeUnitComplexityExposed by
      gaugenumbersimpleDB-Servers, Single Servers and Coordinators

      Number of running Pregel workers

      arangodb_pregel_workers_running_number

      Number of running Pregel workers.

      Introduced in: v3.10.0

      TypeUnitComplexityExposed by
      gaugenumbersimpleDB-Servers, Single Servers and Coordinators

      Number of storing Pregel workers

      arangodb_pregel_workers_storing_number

      Number of storing Pregel workers.

      Introduced in: v3.10.0

      TypeUnitComplexityExposed by
      gaugenumbersimpleDB-Servers, Single Servers and Coordinators

      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

      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 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

      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.


      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: v3.10.6

      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 edge 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 edge cache. This counter increases only for insert, update, replace, and remove operations affecting edge 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 cache of any edge index. This in-memory cache is optional and its 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 edge cache entries

      rocksdb_cache_auto_refill_loaded_total

      This metric shows the total number of automatically refilled in-memory edge cache entries. Entries in the in-memory edge cache are automatically refilled for edge 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 edge cache refill operations for a complete

      edge index

      rocksdb_cache_full_index_refills_total

      This metric shows the total number of refill operations to in-memory edge caches for entire edge 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: v3.10.5

      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: v3.10.6

      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: v3.10.7

      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: v3.10.5

      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: v3.10.5

      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

      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

      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

      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

      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: v3.10.13

      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 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

      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

      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. Note: this metric considers only HTTP and HTTP/2 connections, but not VST connections.

      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 or VST.

      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: v3.10.12

      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: v3.10.7

      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: v3.10.7

      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 (or VST) 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 (or VST) 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 (or VST) 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 (or VST) 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 (or VST) 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 (or VST) 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 (or VST) 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 (or VST) 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 (or VST) 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 (or VST) 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 (or VST) 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 (or VST) 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.


      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.


      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

      On Windows, this figure contains the total number of page faults. On other system, 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. This figure is not reported on Windows.

      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

      On Windows, this figure contains the total amount of memory that the memory manager has committed for the arangod process. On other systems, 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

      Body size in bytes for VST requests

      arangodb_request_body_size_vst (basename)
      arangodb_request_body_size_vst_bucket
      arangodb_request_body_size_vst_sum
      arangodb_request_body_size_vst_count

      Histogram of the body sizes of the received VST requests in bytes. Note that this does include the binary 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: v3.10.12

      TypeUnitComplexityExposed by
      gaugebytesadvancedCoordinators, 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 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: v3.10.13

      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: v3.10.13

      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: v3.10.13

      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: v3.10.13

      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

      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 /_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
        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 /_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
            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