Debugging WEBrick problems?

My site has been up for about 10 days with a moderate load. Today I
discovered the site was unresponsive. I don’t really know how to begin
debugging WEBrick problems. I looked in the
~webroot/log/production.log
file but didn’t see anything obvious.

I killed the ruby server process (had to kill -9) and just restarted it
normally and everything came up fine.

Where would you start hunting for clues? Are there any script/server
switches I could use to debug?

Thanks

You’ve deployed in production mode with webrick?