Maintenance mode for recovery groups is an optional feature. You must explicitly configure Continentalclusters to use this feature. Consider the following guidelines when you move a recovery group into the maintenance mode:

•Configure a shared disk with a file system in all primary clusters and in the recovery cluster. This shared disk is local to the cluster and need not be replicated.

•Configure the CONTINENTAL_CLUSTER_STATE_DIR parameter in the Continentalcluster configuration file with an absolute path to a file system. Create this path in all nodes and reserve it for Continentalclusters. This file system is used to hold the current maintenance mode setting for recovery groups.

•Configure the monitor package control script to mount the file system in the shared disk for the path specified with the CONTINENTAL_CLUSTER_STATE_DIR parameter.

When a recovery group is in the maintenance mode, start up of a recovery package with cmrecovercl, cmrunpkg or cmmodpkg commands is prevented by Continentalclusters for that recovery group.

When a recovery group is in the maintenance mode there is no impact on the availability of the primary packages. The primary package continues to be up and is highly available within the primary cluster (i.e., local failover allowed). Clients can continue to connect to the primary package and access its production data on the primary cluster.

There is no dependency on data replication to move a recovery group into maintenance mode. Array based replication can be suspended or can be in progress. Similarly, logical replication can either be suspended (receiver package is down) or can be resumed (receiver package is up).

Table 7 describes the impact on recovery when a recovery group is in the maintenance mode.

Table 7 Impact of Maintenance Mode

Default Mode

Maintenance Mode

 

 

Recovery package startup using cmrecovercl,

Recovery package startup using cmrecovercl, cmrunpkg,

cmrunpkg, cmmodpkg or cmforceconcl commands

cmmodpkg or cmforceconcl commands is not allowed.

is allowed.

 

 

 

Cross-checking is done between primary and recovery

No impact to primary packages. The primary package

packages to ensure both packages are not up at the

continues to run irrespective of the mode.

same time.

 

The primary package is allowed to start only if the

 

recovery package is down. Similarly, a recovery

 

package is allowed to start only if the primary package

 

is down.

 

 

 

Moving a Recovery Group into Maintenance Mode

Run the following command to disable a recovery group and move it into the maintenance mode:

cmrecovercl -d [-f] -g <recovery group>

Where:

<recovery group> is the name of the recovery group to be disabled.

Understanding Continentalclusters Concepts 43