Monitor the log synchronization status of a standby tenant

After the log synchronization of a standby tenant starts, you can monitor the log synchronization status in real time by using the DBA_OB_TENANTS view, so that you can make timely adjustments.

View the synchronization progress of standby tenants from the sys tenant

You can log on to the sys tenant to view the synchronization progress of all tenants or a specified tenant.

1. Log on to the database as the administrator of the sys tenant of the cluster where the specified standby tenant resides.

2. Execute the following statement to view the synchronization progress of the specified standby tenant.

   Sample statement:

   SELECT TENANT_NAME, TENANT_ROLE, SWITCHOVER_STATUS, SCN_TO_TIMESTAMP(SYNC_SCN)
   FROM oceanbase.DBA_OB_TENANTS WHERE TENANT_NAME = 'oracle_standby';
   +------------------+-------------+-------------------+---------------------------------+
   | TENANT_NAME      | TENANT_ROLE | SWITCHOVER_STATUS | SCN_TO_TIMESTAMP(SYNC_SCN)      |
   +------------------+-------------+-------------------+---------------------------------+
   | oracle_standby   | STANDBY     | NORMAL            | 2023-03-08 14:39:36.089486      |
   +-----------     --+-------------+-------------------+---------------------------------+
   1 row in set
   

   The SCN_TO_TIMESTAMP(SYNC_SCN) field in the query result displays the synchronization progress of the specified standby tenant. You can compare the displayed time with the current time. A large difference indicates that the synchronization progress of the standby tenant lags behind that of the primary tenant.

   For more information about the DBA_OB_TENANTS view, see oceanbase.DBA_OB_TENANTS (MySQL Mode) or DBA_OB_TENANTS (Oracle Mode).

View the synchronization progress of a standby tenant from the current tenant

You can log on to a standby tenant to view the synchronization progress of the current tenant.

1. Log on to the database as the administrator of the standby tenant.

2. Execute the following statement to view the synchronization progress of the current tenant.

   Sample statement:

   • MySQL mode

     SELECT TENANT_NAME, TENANT_ROLE, SWITCHOVER_STATUS, SCN_TO_TIMESTAMP(SYNC_SCN) FROM oceanbase.DBA_OB_TENANTS;
     +------------------+-------------+-------------------+---------------------------------+
     | TENANT_NAME      | TENANT_ROLE | SWITCHOVER_STATUS | SCN_TO_TIMESTAMP(SYNC_SCN)      |
     +------------------+-------------+-------------------+---------------------------------+
     | mysql_standby    | STANDBY     | NORMAL            | 2023-03-10 15:35:36.089486      |
     +------------------+-------------+-------------------+---------------------------------+
     1 row in set
     

   • Oracle mode

     SELECT TENANT_NAME, TENANT_ROLE, SWITCHOVER_STATUS, SCN_TO_TIMESTAMP(SYNC_SCN) FROM DBA_OB_TENANTS;
     +------------------+-------------+-------------------+---------------------------------+
     | TENANT_NAME      | TENANT_ROLE | SWITCHOVER_STATUS | SCN_TO_TIMESTAMP(SYNC_SCN)      |
     +------------------+-------------+-------------------+---------------------------------+
     | oracle_standby   | STANDBY     | NORMAL            | 08-MAR-23 14:39:36.089486       |
     +------------------+-------------+-------------------+---------------------------------+
     1 row in set
     

   The SCN_TO_TIMESTAMP(SYNC_SCN) field in the query result displays the synchronization progress of the standby tenant. You can compare the displayed time with the current time. A large difference indicates that the synchronization progress of the standby tenant lags behind that of the primary tenant.

   For more information about the DBA_OB_TENANTS view, see oceanbase.DBA_OB_TENANTS (MySQL Mode) or DBA_OB_TENANTS (Oracle Mode).

More information

Adjust the log synchronization performance of a standby tenant