[[restore-snapshot-api]]
=== Restore snapshot API
++++
<titleabbrev>Restore snapshot</titleabbrev>
++++

Restores a <<snapshot-restore,snapshot>> of a cluster or specified data streams and indices.

////
[source,console]
----
PUT /_snapshot/my_repository
{
  "type": "fs",
  "settings": {
    "location": "my_backup_location"
  }
}

PUT /_snapshot/my_repository/my_snapshot?wait_for_completion=true

PUT /index_1

PUT /index_2

PUT /index_3

PUT /index_4

PUT _snapshot/my_repository/snapshot_2?wait_for_completion=true
{
  "indices": "index_3,index_4",
  "ignore_unavailable": true,
  "include_global_state": false,
  "metadata": {
    "taken_by": "Elastic Machine",
    "taken_because": "backup testing"
  }
}

POST /index_1/_close

POST /index_2/_close

POST /index_3/_close

POST /index_4/_close

----
// TESTSETUP
////

[source,console]
----
POST /_snapshot/my_repository/my_snapshot/_restore
----
// TEST[s/_restore/_restore?wait_for_completion=true/]

[[restore-snapshot-api-request]]
==== {api-request-title}

`POST /_snapshot/<repository>/<snapshot>`

[[restore-snapshot-api-desc]]
==== {api-description-title}

Use the restore snapshot API to restore a snapshot of a cluster, including all data streams and indices in the snapshot. If you do not want to restore the entire snapshot, you can select specific data streams or indices to restore.

NOTE: You cannot restore a data stream if a stream with the same name already
exists.

You can run the restore operation on a cluster that contains an elected
<<master-node,master node>> and has data nodes with enough capacity to accommodate the snapshot
you are restoring. Existing indices can only be restored if they are
<<indices-close,closed>> and have the same number of shards as the indices in
the snapshot. The restore operation automatically opens restored indices if
they were closed and creates new indices if they do not exist in the cluster.

If a data stream is restored, its backing indices are also restored.
Alternatively, you can restore individual backing indices without restoring an
entire data stream. If you restore individual backing indices, they are not
automatically added to any existing data stream. For example, if only the
`.ds-logs-00003` backing index is restored from a snapshot, it is not
automatically added to the existing `logs` data stream.

include::{es-ref-dir}/snapshot-restore/restore-snapshot.asciidoc[tag=index-settings-data-stream-warning]

[[restore-snapshot-api-path-params]]
==== {api-path-parms-title}

`<repository>`::
(Required, string)
Name of the repository to restore a snapshot from.

`<snapshot>`::
(Required, string)
Name of the snapshot to restore.

[role="child-attributes"]
[[restore-snapshot-api-request-body]]
==== {api-request-body-title}

`ignore_unavailable`::
(Optional, boolean)
If `false`, the request returns an error for any data stream or index that is missing or closed. Defaults to `false`.
+
If `true`, the request ignores data streams and indices in `indices` that are missing or closed.

`ignore_index_settings`::
(Optional, string)
A comma-separated list of index settings that should not be restored from a snapshot.

`include_aliases`::
(Optional, boolean)
If `true`, index aliases from the original snapshot are restored.
Defaults to `true`.
+
If `false`, prevents aliases from being restored together with associated
indices.

[[restore-snapshot-api-include-global-state]]
`include_global_state`::
+
--
(Optional, boolean)
If `false`, the cluster state is not restored. Defaults to `false`.

If `true`, the current cluster state is included in the restore operation.

The cluster state includes:

* Persistent cluster settings
* Index templates
* Legacy index templates
* Ingest pipelines
* {ilm-init} lifecycle policies
--
+
IMPORTANT: By default, the entire restore operation will fail if one or more indices included in the snapshot do not have all primary shards available. You can change this behavior by setting <<restore-snapshot-api-partial,`partial`>> to `true`.

[[restore-snapshot-api-index-settings]]
`index_settings`::
(Optional, string)
A comma-separated list of settings to add or change in all restored indices. Use this parameter to override index settings when restoring snapshots.
+
For data streams, these index settings are applied to the restored backing
indices.
+
For more information regarding all the different index-level settings
that you can specify, see
<<index-modules,index modules>>.

`indices`::
(Optional, string)
A comma-separated list of data streams and indices to restore from the snapshot.
<<multi-index,Multi-index syntax>> is supported.
+
By default, a restore operation includes all data streams and indices in the snapshot. If this
argument is provided, the restore operation only includes the specified data streams and indices.

[[restore-snapshot-api-partial]]
`partial`::
(Optional, boolean)
If `false`, the entire restore operation will fail if one or more indices included in the snapshot do not have all primary shards available. Defaults to `false`.
+
If `true`, allows restoring a partial snapshot of indices with unavailable shards. Only shards that were successfully included in the snapshot
will be restored. All missing shards will be recreated as empty.

[[restore-snapshot-api-rename-pattern]]
`rename_pattern`::
(Optional, string)
Defines a rename pattern to apply to restored data streams and indices. Data streams and indices matching the rename pattern will be renamed according to
<<restore-snapshot-api-rename-replacement,`rename_replacement`>>.
+
The rename pattern is applied as defined by the regular expression that
supports referencing the original text, according to the https://docs.oracle.com/javase/8/docs/api/java/util/regex/Matcher.html#appendReplacement-java.lang.StringBuffer-java.lang.String-[`appendReplacement`] logic.
+
The request will fail if two or more data streams or indices will be renamed into the same name.
+
include::{es-ref-dir}/snapshot-restore/restore-snapshot.asciidoc[tag=rename-restored-data-stream-tag]

[[restore-snapshot-api-rename-replacement]]
`rename_replacement`::
(Optional, string)
Defines the rename replacement string. See <<restore-snapshot-api-rename-pattern,`rename_pattern`>> for more information.

`wait_for_completion`::
(Optional, boolean)
If `false`, the request returns a response when the restore operation initializes.
Defaults to `false`.
+
If `true`, the request returns a response when the restore operation
completes.

[[restore-snapshot-api-example]]
==== {api-examples-title}

The following request restores `index_1` and `index_2` from `snapshot_2`. The `rename_pattern` and `rename_replacement` parameters indicate any index matching the regular expression `index_(.+)` will be renamed using the pattern `restored_index_$1` when restored.

For example, `index_1` will be renamed to `restored_index_1`. `index_2` will be renamed to `restored_index_2`.

[source,console]
----
POST /_snapshot/my_repository/snapshot_2/_restore?wait_for_completion=true
{
  "indices": "index_1,index_2",
  "ignore_unavailable": true,
  "include_global_state": false,
  "rename_pattern": "index_(.+)",
  "rename_replacement": "restored_index_$1",
  "include_aliases": false
}
----

The API returns an acknowledgement if the request succeeds. If the request encounters errors, the response indicates any issues found, such as
open indices that are blocking the restore operation from completing.
