Find the log file using a query like the following;
SELECT logfile_name FROM fnd_concurrent_processes WHERE concurrent_process_id=(SELECT controlling_manager FROM fnd_concurrent_requests WHERE request_id=<reqid>);
As you see, you can even find the concurrent manager's log file using the request_id of a request, that was executed by concurrent manager in question.
It was nice. I found the logfle according a reqid. However, as it was a new Concurrent Manager, I was looking for the informations of its creation, its activation, etc ...
run a concurrent request by assigning it to that custom concurrent manager and then check with the query that I provided you earlier. For instance assign Active Users concurrent program to that manager and run the program.. Then check with the query I provided.
This is a quick solution :)
I m on vacation and got a limited connection. So I can't check on a real EBS system. But normally, you can find the log and its creation time using OS utils -> ls -al, stat and file commands.. In the concurrent manager log directory, check with some suffix such as .mgr then analyze it with file or stat command . .This is an alternative way.