Bug #77423 systemd doesn't define liberal ulimits for number of files
Submitted: 21 Jun 2015 22:03 Modified: 2 Dec 2016 9:37
Reporter: Michael Krieger Email Updates:
Status: Closed Impact on me:
Category:MySQL Server: Packaging Severity:S3 (Non-critical)
Version:5.6 OS:Debian (jessie)
Assigned to: CPU Architecture:Any
Tags: open files, systemd, ulimit

[21 Jun 2015 22:03] Michael Krieger
/lib/systemd/system/mysql.service provided my MySQL Debian packages (APT Repository) does not set liberal limits for systemd to implement when starting MySQL.

Accordingly the addition of items like max_open_files over 1024 will fail with errors such as:
  [Warning] Buffered warning: Could not increase number of max_open_files to more than 1024 (request: ...)
  [Warning] Buffered warning: Changed limits: max_connections: 214 (requested ...)
  [Warning] Buffered warning: Changed limits: table_open_cache: 400 (requested ...)

How to repeat:
Use the default installation and increase max_open_files over 1024.

Suggested fix:
This file should have parameters such as
in order to prevent this oddity.

There may be other parameters which are worthy of reviewing.

MySQL often uses significant resources and its parameters should accommodate that.
[1 Jul 2015 16:48] Michael Krieger
Incorrectly said squeeze- actually jessie
[2 Dec 2016 9:37] Terje Røsten

This has been fixed in MySQL 5.7: