Reported by ibiatiroler via e-mail

> Since I've updated the Role Strategy Plugin plugin to version 2.3.0, there's a malicious behaviour:
After a few minutes (mostly 2-3), the jenkins-master does not respond;
I.e., the Browser waits for the HTTP-response (but w/o timeout) - for at least 2 minutes (after that time, I've restarted the service).
There were no noticeable activities at this time: the Jenkins-instance was idle (0-2% CPU).

> Since you have written in the pull-request #13 (Treat user authorities as roles), that there's a possible performance problems,
that this can still occur with the implemented cache in a huge/large AD-environment?

> Note: We are using the Active Directory plugin for authentication (with recursive group queries, irrelevant groups are removed) and
"only" about 40 users have the permission to log on. BUT, the Windows AD is set up as Forest and contains > 3000 accounts and each
user (with nested groups) is in approx. >50 groups.

> Sorry, I have no log-entries or other hints, traces - I assume that this enhancement makes our master to stop responding;
after reverting to the previous version, this issue has gone.