Service failover is a mechanism to specify a critical process that must be run somewhere in an Essbase cluster if service is disrupted on a processing server. This enables you to preferentially select which processes must be kept running. Any process-type opmn.xml file element may be configured as a service failover such that, once started, OPMN ensures that the configured number of processes for the service are running on Essbase instances somewhere in the cluster. You can configure which Essbase instances participate in the service failover on an instance-by-instance basis. You can configure each instance for preferential selection of running the process on available instances. Only one process-set may be defined for each process-type configured as a service failover. Only one process is run for each service failover instance.
In the following diagram, a service failover process has been started in a cluster where all instances are configured to participate in the service failover.
As shown in the diagram below, if the instance on which the service failover process is running goes down, such as for maintenance or an unprotected power outage or network failure, OPMN selects another participating Essbase instance on which to run the process. All of the instances shown in the diagram are participating in the service failover.
