You may refer the following Note to see if it can help as there is no particular noticed for this
Concurrent Processing - Best Practices for Performance for Concurrent Managers in E-Business Suite (Doc ID 1057802.1)
You may use this navigation and verify primary / secondary node.
SYSADMIN > Concurrent > Manager > Define >
Hope this helps!
You may use this query
select node_name , node_name2,CONCURRENT_QUEUE_NAME from fnd_concurrent_queues