changing the maximum num of connections

nginx.conf

worker_processes    4;
worker_rlimit_nofile 1024768;

events {
    worker_connections  20480;
    use                 epoll;
}

ulimit.md

ulimit

cat /proc/sys/fs/file-max
3296746

With 20480 Connections per worker, the nginx master may need 20480 * 12 (256760) file descriptors.

sudo -i bash -c 'echo "* hard nofile 262400" >> /etc/security/limits.conf'
sudo -i bash -c 'echo "* soft nofile 262400" >> /etc/security/limits.conf'
sudo -i bash -c 'echo "fs.file-max = 3296746" >> /etc/sysctl.conf'

sudo -i sysctl -w fs.file-max=262400
sudo -i sysctl -p

cat /proc/sys/fs/file-max
262400

oops...

sudo vi /etc/security/limits.conf

Remove nofile lines inserted above.

sudo -i sysctl -w fs.file-max=3296746

sudo -i sysctl -p

cat /proc/sys/fs/file-max
3296746

All good again