Performing Maintenance on a Primary

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