Icecast - Too many open files

Question

I'm running an Icecast 2.4.3 server on a CentOS 7. When I have a lot of listeners, I receive these errors and everything stops working:

[2017-06-21  18:56:37] WARN connection/_accept_connection accept() failed with error 24: Too many open files

It's running on "ices" user:

sudo -u ices /opt/icecast/bin/icecast -c /opt/icecast/etc/icecast.xml -b

Or running as root with "changeowner" option to "ices" user.

I set limits.conf:

ices         hard    nofile      65536
ices         soft    nofile      65536

From ulimit:

[root@orfeu inweb]# su ices
[ices@orfeu inweb]$ ulimit -n
65536

But when I check the PID, I get:

tcp        0      0 <IP>:8000       0.0.0.0:*               LISTEN      21650/icecast

[root@orfeu inweb]# cat /proc/21650/limits
Limit                     Soft Limit           Hard Limit           Units
...
Max open files            1024                 4096                 files
...

How can I fix this, to enforce 65536 file descriptors? Thank you.

Answer 1

Probably I found a solution. Need to check when the problem happens again.

I realize that limits.conf set the limits per user. I found out a way to set the limits per process.

/usr/bin/prlimit -n30000 -p `cat /var/run/icecast.pid`

Now I have:

Max open files            30000                30000                files

I don't know if there's a way to always start "icecast" binary with these limits, or always need to run the command against the PID after run.