mjhjmtu

I'm trying to fix the following error that I get after a day or two of running my game server.

2017/12/13 12:08:35 http: Accept error: accept tcp [::]:8081: accept4: too many open files; retrying in 1s

I added "fs.file-max = 2000000" to /etc/sysctl.conf and executed

sysctl -w fs.file-max=2000000
sysctl -p

My global limits are now updated (do I need to reboot?) but the soft and hard limits are still 1024 and 4096 respectively.

Also when using the following command to check for "open files" for root user:

su - root -c 'ulimit -aHS' -s '/bin/bash'

I'm getting 1024 as well.

What does the soft and hard limit do and do I need to change them in order for the global limits to have any effect? And how about the user (root) limit?

Thanks!

The limit you set with sysctl is a system setting that applies to the whole system. It is not a limit that applies to individual processes.

Each process can have no more than N files open where N is the process's NOFILE soft limit, and it can change its own soft limit to no more than the hard limit. Only processes running as root can raise their hard limit. Processes inherit their parent's limits.

The way to change the limit for a single service (which is what you should do) depends on your init system.

• For SysVinit (CentOS ≤6): edit the init script for the service (normally located in /etc/rc.d/init.d) to call ulimit before running the daemon, then restart the service.


• 
  

  For Systemd (CentOS ≥7): edit the service's unit file /etc/systemd/system/my_game_server.service and add a directive

  
  
  

  LimitNOFILE=16384
  

  
  
  

  Then run systemctl daemon-reload to reload the configuration, then restart your service.

  
  

You can change the limits in /etc/security/limits.conf. Log out and in to take effect.

Hardlimit: The boundary for a certain user - can not be increaed by that user during runtime, only decreased: ulimit -Hu 2000. List of Hardlimits: ulimit -Ha

Softlimit: A "soft" boundary within the hardlimit, can be changed by the user during runtime: ulimit -Su 10000.List of Softlimits: ulimit -Sa

Change ulimits for a running process: prlimit -p $$ --nproc=1200:. This will change the number of processes (softlimit) to 1200 for the current shell $$.

You can change the number of limits in file /etc/security/limits.conf (for particular user or for everyone)
You should add like this:

username soft nofile 4096
username hard nofile 5120

and this will set number of open files to 4096 (soft limit) and 5120 as top

After this edit you need to relogin and restrart the service(s) to get this in charge.

As far as I remember ulimit will make changes only till you logout from this user