Background

I am managing a Ruby on Rails application that needs to serve lots of static files too.

My setup presently is:

Debian Linux Lenny 5. Apache 2.2.9 Passenger 2.2.10

The issue

Everything runs fine. I see apache process spinning up, passenger instances get produced and everything works fast and snappy.

Then, after a while Apache doesn't react to demands anymore. Clients get an association and therefore are "awaiting an answerInch, but none of them comes.

I am unable to by hand reproduce this issue. It sometimes happens a couple of hrs following a restart, in other cases it requires a couple of days to occur. Some tips about what I discovered:

Apache process are up Passenger can there be, however it doesn't have any instances spun up (most likely because instances die over time of lack of exercise)

No error messages or problems in /var/log/syslog, /var/log/messages, not in apache's access and errors logs, not during my Rails production log. Nothing.

After I stop and begin apache things are normal again.

Does anyone have clues what is happening here? And just how it may be resolved?