Take the 2-minute tour ×
Server Fault is a question and answer site for professional system and network administrators. It's 100% free, no registration required.

I'm using nginx for serving static files and as a proxy for an Erlang IM server. Each user is using two long-polling http connections. OS is ubuntu server.

On peak hours I see:

> sudo more /proc/sys/fs/file-nr
1024 0 38001

On normal hours the number of file descriptors goes below 1024 but it never exceeds 1024. Users reporting on lost connections when I'm hitting the 1024 limit.

Why am I limited by 1024 file descriptors although the root user (erlang), www-data user (nginx) and open TCP connections are lower than 1024 each? Is there some global 1024 limit?

Do I need to use worker_rlimit_nofile with nginx or is it enough to increase the nofile in limits.conf for all users?

Thanks

More info that might be relevant:

> sudo nano /etc/security/limits.conf
...
root           hard    nofile          30000
root           soft    nofile          30000

> sudo sysctl fs.file-max
fs.file-max = 38001

> ulimit -a
core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 4160
max locked memory       (kbytes, -l) 32
max memory size         (kbytes, -m) unlimited
open files                      (-n) 1024
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 8192
cpu time               (seconds, -t) unlimited
max user processes              (-u) 4160
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited
share|improve this question
add comment

1 Answer

Another user besides root is most likely hitting your file descriptor limit.

Try switching /etc/security/limits.conf to

...
*           hard    nofile          30000
*           soft    nofile          30000

That way every user has a upper limit of 30000.

share|improve this answer
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.