Jenkins went totally unresponsive this morning. I was not even able to SSH into the Ec2 machine where I run my Jenkins (via docker container) on. 

What would be a good strategy to help uncover the cause of the hang? When I relaunch everything, the logs only go back to the point at which I launched the Jenkins docker container.

Should I stream a log file to Splunk, or similar? If so, which file?

This happened around 7:25am California time.. an hour in the morning when nothing's happening. No developers are at work yet so the instance is just sitting there doing nothing.