9.5. Dynamic Control of FailSafe Services

FailSafe allows you to perform a variety of administrative tasks that can help you troubleshoot a system with problems without bringing down the entire system. These tasks include the following:

• You can add or delete nodes from a cluster without affecting the FailSafe services and the applications running in the cluster

• You can add or delete a resource group without affecting other online resource groups

• You can add or delete resources from a resource group while it is still online

• You can change FailSafe parameters such as the heartbeat interval and the node timeout and have those values take immediate affect while the services are up and running

• You can start and stop FailSafe services on specified nodes

• You can move a resource group online, or take it offline

• You can stop the monitoring of a resource group by putting the resource group into maintenance mode. This is not an expensive operation, as it does not stop and start the resource group, it just puts the resource group in a state where it is not available to FailSafe.

• You can reset individual nodes

For information on how to perform these tasks, see Chapter 5, and Chapter 7.