Temporarily terminating read applications on an active standby database
Although an HADR active standby database
can be used to run read-only workloads, its main role is to replay
log records in order to stay synchronized with the HADR primary in
case it has to take over the primary's role.
In cases
where the read-only workload is causing the standby to fall behind
in its log replay, you might want to temporarily terminate all of
the connections to the standby to allow it to catch up.
About this task
Use the following procedure to temporarily make an active standby inaccessible to readers.
Procedure
- Issue the FORCE APPLICATION command. This terminates existing connections to the standby.
- Change the virtual IP configuration. This prevents new connections to the standby.
What to do next
After the standby has caught up with the primary through log replay, you need to revert the virtual IP configuration to its original setting to allow the connections to the active standby to resume.