I noticed my CPU randomly seems to peg to ~18%. This has happened several times without warning.

I used a Jenkins monitoring feature in order to look at all of the threads and I noticed this one thread which seemed to be taking a huge amount of resources and I decided to click on the terminate button on the right

After terminating that thread, the CPU levels returned to their normal levels:

The only clue that I can think of is that I run a script on the master host which uses the jenkins CLI to idempotently ensure certain workers are attached on a 10m interval.. that's why you see a spike every 10m. The CPU problem I am reporting seems to usually kick off at the beginning of those 10m intervals.