I have an Apache server that's accessing source code over NFS (from a separate dedicated NFS file server). Periodically the Apache server stops accepting new requests (effectively bringing down the server), and when I look into it, it's filling up MaxClients. Upon further research, the site is not that busy... the reason the stack filled up was each Apache process is stuck in a "sending Reply" state (all W's via mod_status). Additionally in top, each apache process is in state "lockf", which makes me think it's an NFS issue. I can't find much information about it online, and I've been pulling my hair out this weekend trying to figure it out. Does anyone have any ideas on what might be going on, or how I can further diagnose the problem?
Thanks so much!