Mysql out of control

I have RT-2.1.80 installed and working. For the most part it’s perfect,
but 2 times I have seen Mysql consume all available CPU and after ~10
minutes I restarted mysqld bringing RT back to life.

Are there any good debugging commands I should run to help me (and more
importantly developers) see what’s causing this? I’m going to turn up
the log level in right now.

The only guess I have as to why this happened is I found out 2 people
were logged in as the same user and actively working with RT. It did
happen a second time with only one user logged in as each username, the
only non normal actions was an Admin was adding groups and changing
group membership. I’d like to provide more info, but this is all I have
right now.

We are running Mysql 3.23.54 (RedHat 8.0), Apache 1.3.27, and