The Cluster Service continues to try and fail over a group until it succeeds or until the number of attempts occurs within a predetermined time span. A group’s failover policy specifies the maximum number of failover attempts that can occur in an interval of time. The Cluster Service will discontinue the failover process when it exceeds the number of attempts in the group’s failover policy.
Modifying Your Failover Policy
Because a group’s failover policy provides a framework for the failover process, make sure that your failover policy is appropriate for your particular needs. When you modify your failover policy, consider the following guidelines:
•Define the method in which the Cluster Service detects and responds to individual resource failures in a group.
•Establish dependency relationships between the cluster resources to control the order in which the Cluster Service takes resources offline.
•Specify
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–Threshold and Period control how many times the Cluster Service attempts to fail over a resource in a particular period of time.
•Specify a Possible owner list for your cluster resources. The Possible owner list for a resource controls which cluster nodes are allowed to host the resource.
Failback
When the System Administrator repairs and restarts the failed cluster node, the opposite process occurs. After the original cluster node has been restarted and rejoins the cluster, the Cluster Service will bring the running application and its resources offline, move them from the failover cluster node to the original cluster node, and then restart the application. This process of returning the resources back to their original cluster node is called failback.
You can configure failback to occur immediately at any given time, or not at all. However, be sure to configure the failback time during your offpeak hours to minimize the effect on users, as they may see a delay in service until the resources come back online.
Using MSCS
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