How to set nginx max open files?

Question

Though I have done the following setting, and even restarted the server:

# head /etc/security/limits.conf -n2
www-data soft nofile -1
www-data hard nofile -1
# /         


        

Answer 1

For nginx simply editing nginx.conf and setting worker_rlimit_nofile should change the limitation. I initially thought it is a self-imposed limit of nginx, but it increases limit per process:

worker_rlimit_nofile 4096;

You can test by getting a nginx process ID (from top -u nginx), then run:

cat /proc/{PID}/limits

To see the current limits

Another way on CentOS 7 is by systemctl edit SERVICE_NAME, add the variables there:

[Service]
LimitNOFILE=65536

save that file and reload the service.