nano /etc/sysctl.conf
fs.file-max = 999999 net.core.rmem_max = 16777216 net.core.wmem_max = 16777216 net.ipv4.tcp_rmem = 4096 4096 16777216 net.ipv4.tcp_wmem = 4096 4096 16777216 net.ipv4.tcp_syncookies = 1 # this gives the kernel more memory for tcp # which you need with many (100k+) open socket connections net.ipv4.tcp_mem = 50576 64768 98152 net.core.netdev_max_backlog = 2500
nano /etc/security/limits.conf
* soft nofile 262144 * hard nofile 262144 * soft nproc 262144 * hard nproc 262144
cat /proc/sys/net/ipv4/ip_local_port_range
cat /proc/sys/kernel/threads-max
nano .bashrc
ulimit -t unlimited ulimit -c unlimited
ulimit -a
References
https://lists.launchpad.net/mosquitto-users/msg00163.html