100% CPU every now and then requiring session wipe to fix

[Cyberwizzard]

Every now and then, and especially when a bunch of users logs in, the Lets Chat server goes to 100% CPU, goes to 500% of its normal memory use and generates a lot of disk I/O. I have this issue with version 4.8.0.

The whole chat server is unresponsive and the only 'fix' I found so far is to wipe the 'session' collection in MongoDB, requiring all users to log in again. Since this happens at least once a week, this went from a minor annoyance to being a real problem.

I already tried rebooting the Lets Chat server on a weekly schedule.

I have no idea how to debug the server when it locks up like this, so I don't know what it is doing. Are there any guides on how to proceed? Or would it help to update to master?