HP 3PAR Cluster Extension Software Administrator Guide for Windows (5697-1821, April 2012)

The ApplicationStartup object can be customized to determine whether an application
service starts locally or is transferred back to the remote data center (if possible) to
start immediately without waiting for disk pair resynchronization. This object is used
only if an application service has already been transferred to the secondary site
and no recovery procedure has been applied to the Remote Copy volume group
(the Remote Copy volume group has not been recovered and is not in a normal
state). This process is considered a failback attempt without prior Remote Copy
volume group recovery.
HP 3PAR Cluster Extension can detect the most current copy of your data based on
the Remote Copy volume group information. If HP 3PAR Cluster Extension detects
that the remote HP 3PAR storage system has the most current data, it orders a
resynchronization of the local disk from the remote disk, or it stops the startup process
to enable the cluster software to fail back to the remote HP 3PAR storage system.
If a resynchronization is ordered, HP 3PAR Cluster Extension monitors the progress
of the copy process. If the application service was running on a secondary HP 3PAR
storage system without a replication link, a large number of records may need to
be copied. If the copy process takes longer than the configured application startup
timeout value, the application startup will fail.
Windows cluster
If the ApplicationStartup resource property is set to FASTFAILBACK, and the
FailoverThreshold value is set to a number higher than the current number of clustered
systems for the service or application, the service or application will restart on
configured nodes until one of the following conditions is met:
• The resource is brought online in the remote data center.
• The resource failed because the FailoverThreshold value has been reached.
• The resource failed because the FailoverPeriod timeout value has been reached.
CAUTION: Disable subsequent automated failover procedures for recovery failback
operations. If you want to use HP 3PAR Cluster Extension capabilities to recover a
suspended Remote Copy volume group state during a failover, ensure that subsequent
failover operations are disabled in case the recovery attempt fails. To disable
subsequent failover attempts, set the FailoverThreshold to zero (0) until the recovery
operation has finished successfully.
Valid values FASTFAILBACK (default)
The cluster group is brought online in the remote data center (if possible) without
waiting for resynchronization. The application startup process is stopped locally and
HP 3PAR Cluster Extension reports a data center error. Depending on the cluster
software, the application service cannot start on any system in the local data center,
and the cluster software transfers the application service back to the remote data
center. Use this value to provide the highest level of application service availability.
In a two-node cluster, this process does not work because the target failback system
is not available. In this case, the application service must be started manually, or
the ApplicationStartup object must be set to RESYNCWAIT.
RESYNCWAIT
The online operation in the local cluster group must wait until the Remote Copy
volume group status is no longer in syncing state. HP 3PAR Remote Copy initiates
a resynchronization of the local virtual volume based on the remote virtual volume.
HP 3PAR Cluster Extension monitors the syncing process. If no copy progress is made
after configured ResyncWaitTimeout value, HP 3PAR Cluster Extension returns a
global error. If RESYNCWAIT has been specified for the ApplicationStartup object,
APPLICATION objects 67