Jenkins operational log

Question

We have a situation where something causes our Jenkins master to start leaking memory at a certain time each night. No jobs are running at this time, so I'm not interested in logs of build jobs.
We would like to figure out what is happening around this time, but we cannot see much in the jenkins.out.log, since it doesn't log a lot and lacks timestamps.

Does anyone know if there is a way to turn on more detailed operational (not just errors) logging in Jenkins?

Answer 1

You could also use the Jenkins/Hudson monitoring plugin to see snapshots of memory use etc inside the JVM. Also you could install sar (sysstat) to see how the server itself is doing over time (if Linux).

Answer 2

You could use the logs accessible from the UI (Manage Jenkins » System Log) and set the log level to ALL for the default log recorder in Log Levels. This log is only accessible from the UI though.

Alternatively, you could increase the log level of the regular jenkins.log by passing --debug=9 to the Jenkins command. If you're on CentOS, changing the value of JENKINS_DEBUG_LEVEL in /etc/sysconfig/jenkins has the same effect.