Recently we're having problems running Jenkins, due to a high CPU load on the Jenkins master and as a result an increasingly unresponsive Jenkins web interface.
We run Jenkins using the internal winstone webserver on https using a custom SSL certificate.
The situation seems to be the following:
Some user on the network tries to access a project's workspace for which it lacks permission. The user's https client seems to unfriendly terminate the connection as a result causing a "connection reset" exception.
After that the java VM runs at 100 percent CPU load (like some thread going wild). The web interface will still work at that point but very slow. After a while the web interface won't react any more at all.
Jenkins can't be shut down orderly any more in that state but has to be killed via SIGKILL.
Attached is the relevant part of the log file that seems to lead to that situation.