Primary maintenance must be carried out when the Primary has been switched to a Replica, and then shunned. The Primary can be temporarily switched to a Replica, taken out of the dataservice through shunning, and then added back to the dataservice and then switched back again to be the Primary.
The complete sequence and commands required to perform maintenance on an active Primary are shown in the table below. The table assumes a dataservice with three datasources:
| Step | Description | Command | host1 | host2 | host3 |
|---|---|---|---|---|---|
| 1 | Initial state | Primary | Replica | Replica | |
| 2 |
Set the MAINTENANCE policy
| set policy maintenance | Primary | Replica | Replica |
| 3 | Switch Primary | switch to host2 | Replica | Primary | Replica |
| 4 |
Shun host1
| datasource host1 shun | Shunned | Primary | Replica |
| 5 | Perform maintenance | Shunned | Primary | Replica | |
| 6 |
Recover the Replica ( host1)
| datasource host1 recover | Replica | Primary | Replica |
| 7 | Ensure the Replica has caught up | Replica | Primary | Replica | |
| 8 |
Switch Primary back to
host1
(optional)
| switch to host1 | Primary | Replica | Replica |
| 9 |
Set AUTOMATIC policy
| set policy automatic | Primary | Replica | Replica |