Replication dump commands

Returns the array of collections and their indexes, and the array of Views available. These arrays can be used by replication clients to initiate an initial synchronization with the server. The response will contain all collections, their indexes and views in the requested database if global is not set, and all collections, indexes and views in all databases if global is set. In case global is not set, it is possible to restrict the response to a single collection by setting the collection parameter. In this case the response will contain only information about the requested collection in the collections array, and no information about views (i.e. the views response attribute will be an empty array).

The response will contain a JSON object with the collections, views, state and tick attributes.

collections is an array of collections with the following sub-attributes:

• parameters: the collection properties

• indexes: an array of the indexes of the collection. Primary indexes and edge indexes are not included in this array.

The state attribute contains the current state of the replication logger. It contains the following sub-attributes:

• running: whether or not the replication logger is currently active. Note: since ArangoDB 2.2, the value will always be true

• lastLogTick: the value of the last tick the replication logger has written

• time: the current time on the server

views is an array of available views.

Replication clients should note the lastLogTick value returned. They can then fetch collections’ data using the dump method up to the value of lastLogTick, and query the continuous replication log for log events after this tick value.

To create a full copy of the collections on the server, a replication client can execute these steps:

• call the /inventory API method. This returns the lastLogTick value and the array of collections and indexes from the server.

• for each collection returned by /inventory, create the collection locally and call /dump to stream the collection data to the client, up to the value of lastLogTick. After that, the client can create the indexes on the collections as they were reported by /inventory.

If the clients wants to continuously stream replication log events from the logger server, the following additional steps need to be carried out:

• the client should call /_api/wal/tail initially to fetch the first batch of replication events that were logged after the client’s call to /inventory.

  The call to /_api/wal/tail should use a from parameter with the value of the lastLogTick as reported by /inventory. The call to /_api/wal/tail will return the x-arango-replication-lastincluded header which will contain the last tick value included in the response.

• the client can then continuously call /_api/wal/tail to incrementally fetch new replication events that occurred after the last transfer.

  Calls should use a from parameter with the value of the x-arango-replication-lastincluded header of the previous response. If there are no more replication events, the response will be empty and clients can go to sleep for a while and try again later.

Creates a new dump batch and returns the batch’s id.

The response is a JSON object with the following attributes:

• id: the id of the batch
• lastTick: snapshot tick value using when creating the batch
• state: additional leader state information (only present if the state URL parameter was set to true in the request)

Deletes the existing dump batch, allowing compaction and cleanup to resume.

Extends the time-to-live (TTL) of an existing dump batch, using the batch’s ID and the provided TTL value.

If the batch’s TTL can be extended successfully, the response is empty.

Returns the data from a collection for the requested range.

The chunkSize query parameter can be used to control the size of the result. It must be specified in bytes. The chunkSize value will only be honored approximately. Otherwise a too low chunkSize value could cause the server to not be able to put just one entry into the result and return it. Therefore, the chunkSize value will only be consulted after an entry has been written into the result. If the result size is then greater than chunkSize, the server will respond with as many entries as there are in the response already. If the result size is still less than chunkSize, the server will try to return more data if there’s more data left to return.

If chunkSize is not specified, some server-side default value will be used.

The Content-Type of the result is application/x-arango-dump. This is an easy-to-process format, with all entries going onto separate lines in the response body.

Each line itself is a JSON object, with at least the following attributes:

• tick: the operation’s tick attribute

• key: the key of the document/edge or the key used in the deletion operation

• rev: the revision id of the document/edge or the deletion operation

• data: the actual document/edge data for types 2300 and 2301. The full document/edge data will be returned even for updates.

• type: the type of entry. Possible values for type are:

  • 2300: document insertion/update

  • 2301: edge insertion/update

  • 2302: document/edge deletion

Returns the Merkle tree associated with the specified collection.

The result will be JSON/VelocyPack in the following format:

{
  version: <Number>,
  branchingFactor: <Number>
  maxDepth: <Number>,
  rangeMin: <String, revision>,
  rangeMax: <String, revision>,
  nodes: [
    { count: <Number>, hash: <String, revision> },
    { count: <Number>, hash: <String, revision> },
    ...
    { count: <Number>, hash: <String, revision> }
  ]
}

At the moment, there is only one version, 1, so this can safely be ignored for now.

Each <String, revision> value type is a 64-bit value encoded as a string of 11 characters, using the same encoding as our document _rev values. The reason for this is that 64-bit values cannot necessarily be represented in full in JavaScript, as it handles all numbers as floating point, and can only represent up to 2^53-1 faithfully.

The node count should correspond to a full tree with the given maxDepth and branchingFactor. The nodes are laid out in level-order tree traversal, so the root is at index 0, its children at indices [1, branchingFactor], and so on.

Rebuilds the Merkle tree for a collection.

If successful, there will be no return body.

Returns the revision IDs of documents within the requested ranges.

The body of the request should be JSON/VelocyPack and should consist of an array of pairs of string-encoded revision IDs:

[
  [<String, revision>, <String, revision>],
  [<String, revision>, <String, revision>],
  ...
  [<String, revision>, <String, revision>]
]

In particular, the pairs should be non-overlapping, and sorted in ascending order of their decoded values.

The result will be JSON/VelocyPack in the following format:

{
  ranges: [
    [<String, revision>, <String, revision>, ... <String, revision>],
    [<String, revision>, <String, revision>, ... <String, revision>],
    ...,
    [<String, revision>, <String, revision>, ... <String, revision>]
  ]
  resume: <String, revision>
}

The resume field is optional. If specified, then the response is to be considered partial, only valid through the revision specified. A subsequent request should be made with the same request body, but specifying the resume URL parameter with the value specified. The subsequent response will pick up from the appropriate request pair, and omit any complete ranges or revisions which are less than the requested resume revision. As an example (ignoring the string-encoding for a moment), if ranges [1, 3], [5, 9], [12, 15] are requested, then a first response may return [], [5, 6] with a resume point of 7 and a subsequent response might be [8], [12, 13].

If a requested range contains no revisions, then an empty array is returned. Empty ranges will not be omitted.

Each <String, revision> value type is a 64-bit value encoded as a string of 11 characters, using the same encoding as our document _rev values. The reason for this is that 64-bit values cannot necessarily be represented in full in JavaScript, as it handles all numbers as floating point, and can only represent up to 2^53-1 faithfully.

Returns documents by revision for replication.

The body of the request should be JSON/VelocyPack and should consist of an array of string-encoded revision IDs:

[
  <String, revision>,
  <String, revision>,
  ...
  <String, revision>
]

In particular, the revisions should be sorted in ascending order of their decoded values.

The result will be a JSON/VelocyPack array of document objects. If there is no document corresponding to a particular requested revision, an empty object will be returned in its place.

The response may be truncated if it would be very long. In this case, the response array length will be less than the request array length, and subsequent requests can be made for the omitted documents.

Each <String, revision> value type is a 64-bit value encoded as a string of 11 characters, using the same encoding as our document _rev values. The reason for this is that 64-bit values cannot necessarily be represented in full in JavaScript, as it handles all numbers as floating point, and can only represent up to 2^53-1 faithfully.

Starts a full data synchronization from a remote endpoint into the local ArangoDB database.

The sync method can be used by replication clients to connect an ArangoDB database to a remote endpoint, fetch the remote list of collections and indexes, and collection data. It will thus create a local backup of the state of data at the remote ArangoDB database. sync works on a per-database level.

sync will first fetch the list of collections and indexes from the remote endpoint. It does so by calling the inventory API of the remote database. It will then purge data in the local ArangoDB database, and after start will transfer collection data from the remote database to the local ArangoDB database. It will extract data from the remote database by calling the remote database’s dump API until all data are fetched.

In case of success, the body of the response is a JSON object with the following attributes:

• collections: an array of collections that were transferred from the endpoint

• lastLogTick: the last log tick on the endpoint at the time the transfer was started. Use this value as the from value when starting the continuous synchronization later.

WARNING: calling this method will synchronize data from the collections found on the remote endpoint to the local ArangoDB database. All data in the local collections will be purged and replaced with data from the endpoint.

Use with caution!

Returns the array of collections and indexes available on the cluster.

The response will be an array of JSON objects, one for each collection. Each collection contains exactly two keys, parameters and indexes. This information comes from Plan/Collections/{DB-Name}/* in the Agency, just that the indexes attribute there is relocated to adjust it to the data format of arangodump.