arangorestore Examples

To restore data from a dump previously created with arangodump, ArangoDB provides the arangorestore tool.

Invoking arangorestore

arangorestore can be invoked from the command-line as follows:

arangorestore --input-directory "dump"

This connects to an ArangoDB server (tcp://127.0.0.1:8529 by default), then restores the collection structure and the documents from the files found in the input directory dump. Note that the input directory must have been created by running arangodump before.

arangorestore connects to the _system database by default, using the default endpoint. To override the endpoint, or specify a different user, use one of the following startup options:

  • --server.endpoint <string>: endpoint to connect to
  • --server.username <string>: username
  • --server.password <string>: password to use (omit this and you’ll be prompted for the password)
  • --server.authentication <bool>: whether or not to use authentication

If you want to connect to a different database or dump all databases you can additionally use the following startup options:

  • --server.database <string>: name of the database to connect to. Defaults to the _system database.
  • --all-databases true: restore multiple databases from a dump which used the same option.

Note that the specified user must have access to the database(s).

The arangorestore tool provides the --create-database option. Setting this option to true creates the target database if it does not exist. When creating the target database, the username and passwords passed to arangorestore (in options --server.username and --server.password) are used to create an initial user for the new database.

The option --force-same-database allows restricting arangorestore operations to a database with the same name as in the source dump’s dump.json file. It can thus be used to prevent restoring data into a “wrong” database by accident.

For example, if a dump was taken from database A, and the restore is attempted into database B, then with the --force-same-database option set to true, arangorestore aborts instantly.

The --force-same-database option is set to false by default to ensure backwards-compatibility.

Here’s an example of reloading data to a non-standard endpoint, using a dedicated database name:

arangorestore \
  --server.endpoint tcp://192.168.173.13:8531 \
  --server.username backup \
  --server.database mydb \
  --input-directory "dump" \

Also, more than one endpoint can be provided, such as:

arangorestore \
  --server.endpoint tcp://192.168.173.13:8531 \
  --server.endpoint tcp://192.168.173.13:8532 \
  --server.username backup \
  --server.database mydb \
  --input-directory "dump"

To create the target database when restoring, use a command like this:

arangorestore --server.username backup --server.database newdb --create-database true --input-directory "dump"

In contrast to the above calls, when working with multiple databases using --all-databases true the parameter --server.database mydb must not be specified:

arangorestore --server.username backup --all-databases true --create-database true --input-directory "dump-multiple"

arangorestore prints out its progress while running, and ends with a line showing some aggregate statistics:

Processed 2 collection(s), read 2256 byte(s) from datafiles, sent 2 batch(es)

By default, arangorestore re-creates all non-system collections found in the input directory and loads data into them. If the target database already contains collections which are also present in the input directory, the existing collections in the database are dropped and re-created with the properties and data found in the input directory.

The following parameters are available to adjust this behavior:

  • --create-collection <bool>: set to true to create collections in the target database if they don’t yet exist. If the target database already contains a collection with the same name, then it is dropped and recreated with the same properties as in the dump if the overwrite option is also set. If the overwrite option is not set, an existing collection is used as is, and its properties are not updated nor is its data discarded before restoring. If --create-collection is set to false, then arangorestore does not make any attempts to create the collection or modify its properties. Data is restored into the existing collections without wiping the collection beforehand. If set to false and arangorestore encounters a collection that is present in the input directory but not in the target database, it aborts with a “collection not found” error. The default value for --create-collection is true.
  • --overwrite <bool>: controls whether existing collections are dropped if --create-collection true is used. The default value is true.
  • --import-data <bool>: set to true to load document data into the collections in the target database. Set to false to not load any document data. The default value is true.
  • --include-system-collections <bool>: whether or not to include system collections when re-creating collections or reloading data. The default value is false.

For example, to (re-)create all non-system collections and load document data into them, use:

arangorestore --create-collection true --import-data true --input-directory "dump"

This drops potentially existing collections in the target database that are also present in the input directory.

To include system collections too, use --include-system-collections true:

arangorestore --create-collection true --import-data true --include-system-collections true --input-directory "dump"

To (re-)create all non-system collections without loading document data, use:

arangorestore --create-collection true --import-data false --input-directory "dump"

This also drops existing collections in the target database that are also present in the input directory.

To just load document data into existing non-system collections, use:

arangorestore --create-collection false --import-data true --input-directory "dump"

To restrict reloading to just specific collections, use the --collection option. It can be specified multiple times if required:

arangorestore --collection myusers --collection myvalues --input-directory "dump"

Collections are processed in alphabetical order by arangorestore, with all document collections being processed before all edge collections. This remains valid also when multiple threads are in use.

Note however that when restoring an edge collection no internal checks are made in order to validate that the documents that the edges connect exist. As a consequence, when restoring individual collections which are part of a graph you are not required to restore in a specific order.

When restoring only a subset of collections of your database, and graphs are in use, you need to make sure that you restore all the needed collections (the ones that are part of the graph). Otherwise, you might end up with edges pointing to non-existing documents.

To restrict reloading to specific Views, there is the --view option. Should you specify the --collection parameter, Views are not restored unless you explicitly specify them via the --view option.

arangorestore --collection myusers --view myview --input-directory "dump"

In the case of an arangosearch View, you must make sure that the linked collections are either also restored or already present on the server.

Encryption

See arangodump for details.

Compression

You can optionally let arangorestore compress the data for the network transfer with the --compress-transfer startup option. This can reduce the traffic and thus save time. Set the --compress-request-threshold startup option to define the minimum size for request bodies (in bytes) at which compression is applied.

arangorestore --input-directory "dump" --compress-transfer --compress-request-threshold 250

Reloading Data into a different Collection

arangorestore restores documents and edges with the exact same _key, _from, and _to values as found in the input directory.

With some creativity you can also use arangodump and arangorestore to transfer data from one collection into another (either on the same server or not). For example, to copy data from a collection myvalues in database mydb into a collection mycopyvalues in database mycopy, you can start with the following command:

arangodump --collection myvalues --server.database mydb --output-directory "dump"

This creates two files, myvalues.structure.json and myvalues.data.json, in the output directory. To load data from the datafile into an existing collection mycopyvalues in database mycopy, rename the files to mycopyvalues.structure.json and mycopyvalues.data.json.

After that, run the following command:

arangorestore --collection mycopyvalues --server.database mycopy --input-directory "dump"

Enabling revision trees for older dumps

Introduced in: v3.8.7, v3.9.2

Collections in ArangoDB 3.8 and later can use an internal format that is based on revision trees for replication. Using this format has advantages over the previous format, because changes to the collection on the leader can quickly be detected when trying to get follower shards in sync.

Dumps taken from older versions of ArangoDB, i.e. ArangoDB 3.7 or before, do not contain any information about revision trees. The arangorestore behavior for these collections is as follows:

  • In ArangoDB versions before 3.8.7 and 3.9.2, the collections are restored without revision trees.
  • In ArangoDB versions 3.8.7, 3.9.2 or later, the collections use revision trees by default, but you can opt out of this by invoking arangorestore with the --enable-revision-trees false option.

If the --enable-revision-trees startup option is true (which is the default value), then arangorestore adds the necessary attributes for using revision trees when restoring the collections. It’s only done for the attributes which are not contained in the dump. If the option is set to false, arangorestore does not add the attributes when restoring collections.

Regardless of the setting of this option, arangorestore does not add the attributes, when they are already present in the dump. You may modify the attributes manually in the dump if you want to change their values.

Restoring in a Cluster

To restore data into a Cluster, simply point arangorestore to one of the Coordinators in your Cluster.

If arangorestore is asked to restore a collection, it uses the same number of shards, replication factor, and shard keys as when the collection was dumped. The distribution of the shards to the servers are also the same as at the time of the dump, provided that the number of DB-Servers in the cluster dumped from is identical to the number of DB-Servers in the to-be-restored-to cluster.

To modify the number of shards or the replication factor for all or just some collections, arangorestore provides the options --number-of-shards and --replication-factor. These options can be specified multiple times as well, in order to override the settings for dedicated collections, e.g.

arangorestore --number-of-shards 2 --number-of-shards mycollection=3 --number-of-shards test=4

The above command restores all collections except “mycollection” and “test” with 2 shards. “mycollection” has 3 shards when restored, and “test” has 4. It is possible to omit the default value and only use collection-specific overrides. In this case, the number of shards for any collections not overridden is determined by looking into the numberOfShards values contained in the dump.

The --replication-factor options works in the same way, e.g.

arangorestore --replication-factor 2 --replication-factor mycollection=1

sets the replication factor to 2 for all collections but “mycollection”, which gets a replication factor of just 1.

The options --number-of-shards and replication-factor, as well as the deprecated options --default-number-of-shards and --default-replication-factor, are not applicable to system collections. They are managed by the server.

If a collection was dumped from a single instance and is then restored into a cluster, the sharding is done by the _key attribute by default. You can manually edit the structural description for the shard keys in the dump files if required (*.structure.json).

If you restore a collection that was dumped from a cluster into a single ArangoDB instance, the number of shards, replication factor and shard keys are silently ignored.

Factors affecting speed of arangorestore in a Cluster

The following factors affect speed of arangorestore in a Cluster:

  • Replication Factor: the higher the replication factor, the more time the restore takes. To speed up the restore you can restore using a replication factor of 1 and then increase it again after the restore. This reduces the number of network hops needed during the restore.
  • Restore Parallelization: if the collections are not restored in parallel, the restore speed is highly affected. A parallel restore can be done by using the --threads option of arangorestore. Depending on your specific case, you might be able to achieve additional parallelization by restoring on multiple Coordinators at the same time.

Restoring collections with sharding prototypes

arangorestore yields an error when you try to restore a collection whose shard distribution follows a collection (distributeShardsLike property) which does not exist in the cluster and which was not dumped together with the other collection:

arangorestore --collection clonedCollection --server.database mydb --input-directory "dump"

WARNING [c6658] {restore} Error while creating document collection 'clonedCollection': got invalid response from server: HTTP 500: 'Collection not found: prototypeCollection in database _system' while executing restoring collection with this requestPayload: ...

ERROR [cb69f] {restore} got invalid response from server: HTTP 500: 'Collection not found: prototypeCollection in database _system' while executing restoring collection with this requestPayload: ...

INFO [a66e1] {restore} Processed 0 collection(s) from 1 database(s) in 0.04 s total time. Read 0 bytes from datafiles, sent 0 data batch(es) of 0 bytes total size.

You need to dump and restore collections that follow the sharding of a prototype collection together with the prototype collection:

arangorestore --collection clonedCollection --collection prototypeCollection --server.database mydb --input-directory "dump"

...
INFO [a66e1] {restore} Processed 2 collection(s) from 1 database(s) in 1.12 s total time. Read 0 bytes from datafiles, sent 0 data batch(es) of 0 bytes total size.

Restore into an authentication-enabled ArangoDB

Of course you can restore data into a password-protected ArangoDB as well. However this requires certain user rights for the user used in the restore process. The rights are described in detail in the Managing Users chapter. For restore this short overview is sufficient:

  • When importing into an existing database, the given user needs Administrate access on this database.
  • When creating a new database during restore, the given user needs Administrate access on _system. The user is promoted to Administrate access on the newly created database.

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