Check mysql-table-locks

Overview

Checks whether a certain percentage of table locks had to wait in MySQL/MariaDB. Logic is taken from MySQLTuner script:mysql_stats(), v1.9.8.

Hints:

Fact Sheet

Check Plugin Download

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

Check Interval Recommendation

Once an hour

Can be called without parameters

Yes

Compiled for

Linux, Windows

Requirements

User with no privileges, locked down to 127.0.0.1 - for example monitoring\@127.0.0.1. Usernames in MySQL/MariaDB are limited to 16 chars in specific versions.

3rd Party Python modules

pymysql

Help

usage: mysql-table-locks [-h] [-V] [--always-ok]
                         [--defaults-file DEFAULTS_FILE]
                         [--defaults-group DEFAULTS_GROUP]
                         [--timeout TIMEOUT]

Checks whether a certain percentage of table locks had to wait in
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.
  --defaults-file DEFAULTS_FILE
                        Specifies a cnf file to read parameters like user,
                        host and password from (instead of specifying them on
                        the command line), for example
                        `/var/spool/icinga2/.my.cnf`. Default:
                        /var/spool/icinga2/.my.cnf
  --defaults-group DEFAULTS_GROUP
                        Group/section to read from in the cnf file. Default:
                        client
  --timeout TIMEOUT     Network timeout in seconds. Default: 3 (seconds)

Usage Examples

./mysql-table-locks --defaults-file=/var/spool/icinga2/.my.cnf

Output:

100% table locks acquired immediately (2.6K immediate / 2.6K locks).

States

  • WARN if less than 95% table locks were completed immediately.

Perfdata / Metrics

Name

Type

Description

mysql_pct_table_locks_immediate

Percentage

Table_locks_immediate / (Table_locks_waited + Table_locks_immediate) * 100

mysql_table_locks_immediate

Continous Counter

Number of table locks which were completed immediately.

mysql_table_locks_waited

Continous Counter

Number of table locks which had to wait. Indicates table lock contention.

Credits, License