Check mysql-system

Overview

Checks system requirements and kernel settings specifically for MySQL/MariaDB. Logic is taken from MySQLTuner script:get_kernel_info(), v1.9.8.

Unlike MySQLTuner, this plugin does not check if all processes other than MySQL/MariaDB use more than 15% of the total system memory. One reason for this is that you may want or need to run a small DB server on an application server and have it well tuned for that use case. Another reason is that if you are running MySQL/MariaDB on an application server with a lot of RAM, the DB may not need or require 85% RAM.

Hints:

  • See additional notes for all mysql monitoring plugins

  • Does not need access to MySQL/MariaDB itself.

  • Must be running locally on the MySQL/MariaDB server to be able to check the system requirements.

  • On Windows there are no kernel settings that can be checked.

Fact Sheet

Check Plugin Download

https://github.com/Linuxfabrik/monitoring-plugins/tree/main/check-plugins/mysql-system

Check Interval Recommendation

Every 5 minutes

Can be called without parameters

Yes

Compiled for

Linux, Windows

3rd Party Python modules

psutil

Help

usage: mysql-system [-h] [-V] [--always-ok]
                    [--maxportsallowed MAXPORTSALLOWED]

Checks system requirements and kernel settings specifically for MySQL/MariaDB.

options:
  -h, --help            show this help message and exit
  -V, --version         show program's version number and exit
  --always-ok           Always returns OK.
  --maxportsallowed MAXPORTSALLOWED
                        Number of ports opened allowed on this host. Default:
                        0 (check disabled)

Usage Examples

./mysql-system --maxportsallowed 15

Output:

There are too many listening ports: 56 opened > 15 allowed (consider dedicating a server for your database installation with less services running on). vm.swappiness is 60, should be <= 10 (use `echo 10 > /proc/sys/vm/swappiness`). sunrpc.tcp_slot_table_entries is 2, should be > 100 (use `echo 128 > /proc/sys/sunrpc/tcp_slot_table_entries`).

States

  • WARN if there are too many listening ports.

  • WARN if any of the checked Linux Kernel parameters is not in the optimal range.

  • OK in all other cases.

Perfdata / Metrics

Name

Type

Description

mysql_kernel_fs.aio-max-nr

Number

Defines the maximum number of asynchronous I/O operations the system can handle on the server.

mysql_kernel_sunrpc.tcp_slot_table_entries

Number

Sets the number of (TCP) RPC entries to pre-allocate for in-flight RPC requests (essentially the minimum).

mysql_kernel_vm.swappiness

Percentage

Changes the balance between swapping out runtime memory, as opposed to dropping pages from the system page cache.

mysql_opened_ports

Number

Number of opened ports.

Credits, License