Debian 8.4 jessie ulimit issue: Operation not permitted.

[tholu]

When starting the redis-server on Debian 8.4, it cannot increase the maximum open files limit.

24401:M 13 Apr 13:50:01.156 # You requested maxclients of 10000 requiring at least 10032 max file descriptors.
24401:M 13 Apr 13:50:01.156 # Redis can't set maximum open files to 10032 because of OS error: Operation not permitted.
24401:M 13 Apr 13:50:01.156 # Current maximum open files is 4096. maxclients has been reduced to 4064 to compensate for low ulimit. If you need higher maxclients increase 'ulimit -n'.
                _._
           _.-``__ ''-._
      _.-``    `.  `_.  ''-._           Redis 3.0.7 (00000000/0) 64 bit
  .-`` .-```.  ```\/    _.,_ ''-._
 (    '      ,       .-`  | `,    )     Running in standalone mode
 |`-._`-...-` __...-.``-._|'` _.-'|     Port: 6379
 |    `-._   `._    /     _.-'    |     PID: 24401
  `-._    `-._  `-./  _.-'    _.-'
 |`-._`-._    `-.__.-'    _.-'_.-'|
 |    `-._`-._        _.-'_.-'    |           http://redis.io
  `-._    `-._`-.__.-'_.-'    _.-'
 |`-._`-._    `-.__.-'    _.-'_.-'|
 |    `-._`-._        _.-'_.-'    |
  `-._    `-._`-.__.-'_.-'    _.-'
      `-._    `-.__.-'    _.-'
          `-._        _.-'
              `-.__.-'

24401:M 13 Apr 13:50:01.156 # Server started, Redis version 3.0.7
24401:M 13 Apr 13:50:01.203 * DB loaded from disk: 0.046 seconds
24401:M 13 Apr 13:50:01.203 * The server is now ready to accept connections on port 6379

As root:

$ ulimit -n
65536

I guess it's because redis-server runs under the user redis on Debian. What is the preferred way to increase the maximum open files for non-root users on Debian?

[tholu]

Note: Version 3.0.7 was from dotdeb, issue is the same with 3.0.6 from Debian jessie backports.

[tholu]

Solution:

edit /lib/systemd/system/redis-server.service and add to the [Service] section the line (after: User=redis and Group=redis) LimitNOFILE=65536

run: systemctl daemon-reload && systemctl restart redis-server

Thanks to http://serverfault.com/questions/770037/debian-8-4-jessie-set-open-files-limit-for-redis-user/