When you create a PowerCenter Repository Service, service processes are enabled by default on the designated nodes, even if you do not enable the service. You disable and enable service processes on the Processes view. You may want to disable a service process to perform maintenance on the node or to tune performance.
If you have the high availability option, you can configure the service to run on multiple nodes. At any given time, a single process is running for the PowerCenter Repository Service. The service continues to be available as long as one of the designated nodes for the service is available. With the high availability option, disabling a service process does not disable the service if the service is configured to run on multiple nodes. Disabling a service process that is running causes the service to fail over to another node.