How to Retrieve and Restore Snapshots from S3 Repository in OpenSearch

Step 1: List Available Snapshots

First, you need to list the snapshots available in your S3 repository. You can do this by running the following query:

GET /_snapshot/my_s3_repository/_all

This will return a list of all snapshots in the my_s3_repository. The response will include details like the snapshot id, creation date, and state (e.g., success, partial).

Step 2: Restore a Snapshot

Once you’ve identified the snapshot you want to restore, you can proceed with the restoration process. Here’s an example of how to restore an index from a snapshot:

POST /_snapshot/my_s3_repository/snapshot_id/_restore
{
  "indices": "my_index",
  "ignore_unavailable": true,
  "include_global_state": false,
  "include_aliases": false,
  "partial": false
}

• Replace snapshot_id with the actual snapshot ID you retrieved earlier.
• Specify the index to restore in the "indices" field (e.g., "my_index").
• "ignore_unavailable": true allows the restoration to proceed even if the index is unavailable.
• “include_global_state": false means you won’t restore the global cluster state (optional).
• "include_aliases": false ensures that index aliases are not included in the restore process.
• "partial": false ensures that the entire snapshot is restored, not just partial data.

Step 3: Monitor the Restore Process

After initiating the restore, OpenSearch will start the process. You can monitor the status of the restore operation by checking the tasks:

GET /_cat/tasks?v

This will show you the status of ongoing tasks, including restores. Once completed, your index (restored_my_index) will be available for use.