[asterisk-users] Too many open files: what might cause this?

[Adam Moffett]

So a few people just reported that they couldn't make any calls.  I 
logged into asterisk and at first everything on the console looked 
normal, then I got swamped with messages about too many open files.

This is from my asterisk/messages log file:
[Oct  2 16:46:00] WARNING[19429] rtp.c: Unable to allocate RTCP socket: 
Too many open files
[Oct  2 16:46:00] WARNING[19429] udptl.c: Unable to allocate socket: Too 
many open files
[Oct  2 16:46:00] WARNING[19429] acl.c: Cannot create socket
[Oct  2 16:46:00] WARNING[19429] channel.c: Channel allocation failed: 
Can't create alert pipe! Try increasing max file descriptors with ulimit -n

Messages like that repeat a few dozen times, and then I get this one....

manager.c: Accept returned -1: Too many open files

...and that repeated tens of thousands of times.  I killed asterisk and 
restarted it.  Looks normal again.

What the heck just happened?  A bug? Was I attacked? Maybe I'm honestly 
hitting some system limit and I should bump up max file descriptors like 
the message says?  We do have a few hundred SIP peers and maybe we'll 
hit 20-30 simultaneous calls at peak times but I didn't think that was 
particularly high load.

This is Asterisk 1.4.44.  I know the 1.4 branch is old, but it had been 
trouble free for years (until now), and I'd have to rewrite some config 
syntax to upgrade so I didn't see a need to do it.