Background
I'm running a Ruby on Rails application that has to serve a lot of static files as well.
My setup currently is:
Debian Linux Lenny 5.0 Apache 2.2.9 Passenger 2.2.10
The problem
Everything runs fine. I see apache process spinning up, passenger instances get created and everything works fast and snappy.
Then, after some time Apache does not respond to requests any more. Clients do get a connection and are "waiting for a response", but none comes.
I cannot manually reproduce this problem. Sometimes it occurs a few hours after a restart, other times it takes a few days to happen. Here's what I found:
Apache process are up; Passenger is there, but it does not have any instances spun up (probably because instances die after a period of inactivity)
No error messages or problems in /var/log/syslog, /var/log/messages, not in apache's access and errors logs, not in my Rails production log. Nothing.
When I stop and start apache everything is back to normal.
Does any one have any clues what's happening here? And how it can be resolved?