How to find the Preferred node in Oracle RAC?

 

To find the preferred node in Oracle RAC from the configuration. It find the details from Oracle Cluster Registry (OCR). It displays the Oracle Restart configuration information

$ srvctl config service -d db01 db01_Kline PREF: db0101t1 AVAIL: db01t2 db01_watch PREF: db01t2 db01t1 AVAIL:

To find the status of the services, on which instances, it  is running

$ srvctl status service -d db01 Service db01_Kline is running on instance(s) db01t2 Service db01_watch is running on instance(s) db01t2, db01t1

To relocate the services from one node to another or one instance to another

srvctl relocate service -d db_unique_name -s service_name {-c source_node -n target_node | -i old_instance_name -t new_instance_name} [-f]

What is Service in Oracle RAC?

Services allow you granular definition of workload and the DBA can dynamically define which instances provide the service. Connection Load Balancing (provided by Oracle Net Services) still needs to be set up to allow the user connections to be balanced across all instances providing a service.