Make backups in replication environments¶
There are options specific to back up from a replication replica.
The --slave-info option¶
This option is useful when backing up a replication replica server. It prints the
binary log position and name of the source server. It also writes this
information to the xtrabackup_slave_info file as a CHANGE MASTER
statement.
This option is useful for setting up a new replica for this source.
You can start a replica server with this backup and issue the statement saved in the
xtrabackup_slave_info file. More details of this procedure can be found
in How to setup a replica for replication in 6 simple steps with Percona XtraBackup.
The --safe-slave-backup option¶
In order to assure a consistent replication state, this option stops the replication
SQL thread and waits to start backing up until Slave_open_temp_tables in
SHOW STATUS is zero. If there are no open temporary tables, the backup will
take place, otherwise the SQL thread will be started and stopped until there are
no open temporary tables. The backup will fail if Slave_open_temp_tables
does not become zero after --safe-slave-backup-timeout
seconds (defaults to 300 seconds). The replication SQL thread will be restarted when
the backup finishes.
Note
Prior to Percona XtraBackup 8.0.22-15.0, using a safe-slave-backup stops the SQL replica thread after the InnoDB tables and before the non-InnoDB tables are backed up.
As of Percona XtraBackup 8.0.22-15.0, using a safe-slave-backup option stops the SQL replica thread before copying the InnoDB files.
Using this option is always recommended when taking backups from a replica server.
Warning
Make sure your replica is a true replica of the source before using it as a source for backup. A good tool to validate a replica is pt-table-checksum.