Restoring a cluster

Restore the data in a cluster from the stored backups.

You can restore data to a cluster from local keyspace backups and backups stored to cloud storage providers like Amazon S3. These restores can be from a particular point-in-time if you enabled commitlog backups.

When performing a restore operation, you can restore all the keyspaces from a backup or select specific keyspaces and tables.

When restoring from backups stored on Amazon S3, OpsCenter will choose an agent to determine which nodes in the cluster have data that needs to be restored. The SSTables stored in the S3 bucket are sorted into directories with the node ID of original node. If the cluster topology is unchanged from when the backup was taken, OpsCenter will tell each node to restore the set of SSTables that were stored on that node before. If the cluster topology has changed since the backup was completed, OpsCenter will try to match the SSTables to the node that originally stored the SSTable, and will distribute the remaining SSTables to the remaining nodes to distribute the load evenly.

If you are doing a point-in-time restore, your cluster topology must not have changed since the backup. Attempting to perform a point-in-time restore on a cluster whose topology has changed will result in a failure. We recommend that you perform a snapshot backup before any topology changes. You can then restore the cluster based on that backup.