Disk Persistence Backup and Restore

Disk persistence backup can be performed without interruption to clients while servers are running.

Disk persistence backup saves a copy of message and acknowledgment data for a persistence service at a single point in time.

By default, backup copies are written to the data directory of each persistence service. A custom backup directory can be configured by specifying the savedir parameter in the FTL server YAML configuration file. See Persistence Service Configuration Parameters.

If the original disk persistence files are lost, the persistence state can be restored from a backup copy. This effectively sets the persistence service back in time to the point when the backup was taken.

See FTL Administration Utility for the commands to backup or restore persistence data.

Some example commands to backup/restore follow:

tibftladmin --ftlserver <url> --backup_persist --cluster <cluster_name>

tibftladmin --restore_persist --name <persistence_service_name> --datadir <path> --backupdir <path>

Note the following differences between backups and saving the state of the persistence cluster.

You use backups only when disk persistence is enabled.
Unlike saving the state of the persistence cluster (which involves suspending the cluster), backups do not prevent clients from sending or receiving messages while the backup is in progress.

For details saving and loading the state of any persistence cluster, including in-memory clusters, see Saving and Loading Persistence State.