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Check mysql-slow-queries

Overview

Checks the slow query log, which is a record of SQL queries that took a long time to perform on MySQL/MariaDB. Logic is taken from MySQLTuner script:mysql_stats(), v1.9.8.

Hints:

Fact Sheet

Fact Value
Check Plugin Download https://github.com/Linuxfabrik/monitoring-plugins/tree/main/check-plugins/mysql-slow-queries
Check Interval Recommendation Every 5 minutes
Can be called without parameters Yes
Compiled for Windows No
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-slow-queries [-h] [-V] [--always-ok]
                          [--defaults-file DEFAULTS_FILE]
                          [--defaults-group DEFAULTS_GROUP]
                          [--timeout TIMEOUT]

Checks the slow query log, which is a record of SQL queries that took a long
time to perform on 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-slow-queries --defaults-file=/var/spool/icinga2/.my.cnf

Output:

Slow queries: 7.0% (7.0 slow queries/100.0 questions) [WARNING]. Set long_query_time <= 10. Enable the slow_query_log to troubleshoot bad queries.

States

  • WARN if the number of slow queries is more than 5% of all queries.

Perfdata / Metrics

Name Type Description
mysql_long_query_time Seconds If a query takes longer than this many seconds to execute, the Slow_queries status variable is incremented and, if enabled, the query is logged to the slow query log.
mysql_questions Continous Counter Number of statements executed by the server, excluding COM_PING, COM_STATISTICS, COM_STMT_PREPARE, COM_STMT_CLOSE, and COM_STMT_RESET statements. Doesn't count statements executed within stored programs.
mysql_slow_queries Continous Counter Number of queries which took longer than long_query_time to run. The slow query log does not need to be active for this to be recorded.
mysql_pct_slow_queries Percentage Slow_queries / Questions * 100

Credits, License