Apache File Descriptor Limit?

Did someone run into hitting limits in Apache?
We have here a client where the web app runs and after some days you can’t connect any more to the server as it can’t run another child process. Seems like it’s running out of file descriptors.

Linux in general has limits on open file descriptors - really depends on what distro etc
Its usually fairly high (like 75000 for a single login)
ulimit can tell more

if you su into apache’s account and run ulimit -Hn and ulimit -Sn then you should get an idea of what the limits for apache are

you may need to add a line to the beginning of apache’s config like ulimit -n 20000 to increase the number of open files it’s allowed