Movatterモバイル変換

The plugins for semisynchronous replication expose a number of status variables that enable you to monitor their operation. To check the current values of the status variables, useSHOW STATUS:

mysql> SHOW STATUS LIKE 'Rpl_semi_sync%';

Beginning with MySQL 8.0.26, new versions of the source and replica plugins are supplied, which replace the terms“master” and“slave” with“source” and“replica” in system variables and status variables. If you install the newrpl_semi_sync_source andrpl_semi_sync_replica plugins, the new system variables and status variables are available but the old ones are not. If you install the oldrpl_semi_sync_master andrpl_semi_sync_slave plugins, the old system variables and status variables are available but the new ones are not. You cannot have both the new and the old version of the relevant plugin installed on an instance.

AllRpl_semi_sync_xxx status variables are described atSection 7.1.10, “Server Status Variables”. Some examples are:

When the source switches between asynchronous or semisynchronous replication due to commit-blocking timeout or a replica catching up, it sets the value of theRpl_semi_sync_source_status orRpl_semi_sync_master_status status variable appropriately. Automatic fallback from semisynchronous to asynchronous replication on the source means that it is possible for therpl_semi_sync_source_enabled orrpl_semi_sync_master_enabled system variable to have a value of 1 on the source side even when semisynchronous replication is in fact not operational at the moment. You can monitor theRpl_semi_sync_source_status orRpl_semi_sync_master_status status variable to determine whether the source currently is using asynchronous or semisynchronous replication.