5.14.1. Performing Maintenance on a Single Slave

Performing maintenance on a single slave can be achieved by temporarily shunning the slave (while in AUTOMATIC policy mode) and doing the necessary maintenance. Shunning a datasource in this way will temporarily remove it from the dataservice, and prevent active and new connections from using the datasource for operations.

The steps are:

  1. Shun the slave:

    [LOGICAL:EXPERT] /alpha > datasource host2 shun

    Shunning a datasource does not put the replicator offline, so the replicator should also be put in the offline state to prevent replication and changes being applied to the database:

    [LOGICAL:EXPERT] /alpha > replicator host2 offline
  2. Perform the required maintenance, including updating the operating system, software or hardware changes.

  3. Validate the server configuration :

    shell> tpm validate
  4. Recover the slave back to the dataservice:

    [LOGICAL:EXPERT] /alpha > datasource host2 recover

Once the datasource is added back to the dataservice, the status of the node should be checked to ensure that the datasource has been correctly added back, and the node is ONLINE and up to date.

While the datasource is shunned, the node can be shutdown, restarted, upgraded, or any other maintenance. Throughout the process, the slave should be monitored to ensure that the datasource is correctly added back into the dataservice, and has caught up with the master. Any problems should be addressed immediately.