Level: Critical

Purpose: Alert Errigal engineers to a problem with replication to the secondary database(s). Replication databases are used for Reporting Applications, issues with replication mean the data becomes out of date and customer reports will be incorrect.

Scenario: MySQL Slave IO thread has not been running on <server> for 5m.

Resolution: Check the replication status on the server, 'show slave status'. Confirm slave io thread is actually not running. Check InnoDB engine logs to try to determine why replication stopped. To restart the IO process, Run 'stop slave' followed by 'start slave', check if replication status is restored.

If the replica database still refuses to resume, examine the error column in 'show slave status' and continues the investigation from this point.

Manual Action Steps:

- Check errors in 'show slave status'
- Restart replication on the replica
    - stop slave;
    - start slave;

Auto Clear: Yes