I'm not even sure how to ask this question, so I'm just throwing out some details to see if anyone has any ideas about what might be happening.
I'm running RStudio Server Professional (Academic license) for use in my research group and graduate classes. For the last couple of months, I periodically login to the /admin panel, and the CPU usage will be pegged at 32 cores, and will have been sitting there for days. When I login to the server directly, and check the processes, there are always several cron jobs running from some of the users, splitting the cores evenly across them (in particular, two graduate students who are regular users of the RStudio server).
When I check with them, they aren't actually running anything, and the sessions check shows that they aren't doing anything in specific rsessions. But the only thing that these students do on this server is use RStudio. They don't login via SSH, they don't run any other services, nothing.
So does anyone have any idea what might be triggering an extremely high computational load via cron job, but not as part of an explicit rsession? It's happened half a dozen times in the last two months, and happened again this morning (and for the last three days, it turns out), and I'm out of ideas to try, aside from disabling those user accounts' access to cron jobs in an attempt to force an error or bug which reveals the culprit.