Linux | Too many open files

With systemd:

/etc/systemd/system.conf

DefaultLimitNOFILE=128000


You are a lucky admin who is NOT running systemd:
/etc/security/limits.conf
* soft nofile 128000
* hard nofile 128000 
* hard nproc 128000
* soft nproc 128000
root soft nofile 128000
root hard nofile 128000 

Check with

 # ulimit -n