I've setup a radiant 0.9 (edge) instance running on a 256MB Slicehost slice
(running Ubuntu Hardy) and am noticing some significant performance issues.
Wonder if anyone might shed some light.

The http sever is litespeed. Database is mysql. Monitoring with "top" I see
lshttpd (litespeed) using 0.7-1% of memory, mysqld using 2-3%. Neither
process uses any negligible cpu. "free -m" shows numbers like:
  -/+ buffers/cache:        160         95
  Swap:            511         90        421

On the other hand, there are usually 2-4 ruby processes each using about
20-30% memory, and peaking at about 25% cpu usage. Machine load average
ranges from .01 to .9.

Under these circumstances, I'm seeing these kinds of numbers in the
production.log when accessing pages on the site:

  Completed in 1445ms (DB: 127) ...
  Completed in 1838ms (DB: 317) ...
  Completed in 4037ms (DB: 998) ...
  Completed in 4865ms (DB: 488) ...

These are "good" numbers; sometimes the total completed is in the
20000-40000ms range! I don't understand where the bottleneck is. The db
times are consistently less than 1000ms and usually under 500ms.

What's worse though is over time, no idea why, the ruby processes will start
to runaway and I'll end up with 8-10 of them each vying for 20-30% of
memory. Machine load avg spikes up to 14 and the system is essentially
unusable and needs a reboot.

I'm considering bumping the slice memory up to 512MB, but am concerned that
all it will do is delay the inevitable runaway ruby processes.

Anyone have any idea what might be going on here? Anything I can do to
pinpoint the cause of the problem?

Any and all help greatly appreciated.

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