When a service is running on a grid, the failover behavior depends on the following sources of failure:
Master Service Process
If you disable the master service process, the Service Manager elects another node to run the master service process. If the master service process shuts down unexpectedly, the Service Manager tries to restart the process before electing another node to run the master service process.
The master service process then reconfigures the grid to run on one less node. The PowerCenter Integration Service restores the state of operation, and the workflow fails over to the newly elected master service process.
The PowerCenter Integration Service can recover the workflow based on the workflow state and recovery strategy. If the workflow was enabled for high availability recovery, the PowerCenter Integration Service restores the state of operation for the workflow and recovers the workflow from the point of interruption. When the PowerCenter Integration Service restores the state of operation for the service, it restores workflow schedules, service requests, and workflows. The PowerCenter Integration Service performs failover and recovers the schedules, requests, and workflows.
If a scheduled workflow is not enabled for high availability recovery, the PowerCenter Integration Service removes the workflow from the schedule.
Worker Service Process
If you disable a worker service process, the master service process reconfigures the grid to run on one less node. If the worker service process shuts down unexpectedly, the Service Manager tries to restart the process before the master service process reconfigures the grid.
After the master service process reconfigures the grid, it can recover tasks based on task state and recovery strategy.
Because workflows do not run on the worker service process, workflow failover is not applicable.
Service
When the PowerCenter Integration Service becomes unavailable, you must enable the service and start the service processes. You can manually recover workflows and sessions based on the state and the configured recovery strategy. Workflows start if they are configured to run continuously or on initialization. You must reschedule all other workflows.
Node
When the node running the master service process becomes unavailable, the failover behavior is the same as the failover for the master service process. When the node running the worker service process becomes unavailable, the failover behavior is the same as the failover for the worker service process.
You cannot configure a PowerCenter Integration Service to fail over in safe mode when it runs on a grid.