You would be far better off using the sar, iostat, and vmstat commands to monitor your machine. They will give you much better information about what is happening than top will. They do exactly what you want, without the overhead of starting perl from a cronjob every ten minutes (which would probably throw your stats.)

These tools are not process specific, so I would use these in combination with the output of ps. Then you could monitor the amount of ram per process.

I'm very interested to see if there are any solutions that are more Perl specific. Some of the *::proc modules look promising, but I've never used them.

If the server bogs down after a semi-regular interval you could just stop and start the server every 4 hours from a cronjob. Mercy killing it before it has a chance to kill itself.

HTH