Check mysql-temp-tables

Overview

Checks the number of on-disk versus in-memory temporary tables created in MySQL/MariaDB. Logic is taken from MySQLTuner script:mysql_stats(), v1.9.8.

Hints:

  • On RHEL 7+, one way to install the Python MySQL Connector is via pip install pymysql

  • Compared to check_mysql / MySQLTuner this check currently:

    • supports only simple login with username/password (not via SSL/TLS)

    • does not support a connection via socket

Fact Sheet

Check Plugin Download

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

Check Interval Recommendation

Every 15 minutes

Can be called without parameters

Yes

Available for

Python 3, Windows

Requirements

Python module pymysql; 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.

Help

usage: mysql-temp-tables [-h] [-V] [--always-ok] [-H HOSTNAME] [-p PASSWORD]
                         [--port PORT] [-u USERNAME]

Checks the number of on-disk versus in-memory temporary tables created 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.
  -H HOSTNAME, --hostname HOSTNAME
                        MySQL/MariaDB hostname. Default: 127.0.0.1
  -p PASSWORD, --password PASSWORD
                        Use the indicated password to authenticate the
                        connection. Default:
  --port PORT           MySQL/MariaDB port. Default: 3306
  -u USERNAME, --username USERNAME
                        MySQL/MariaDB username. Default: root

Usage Examples

./mysql-temp-tables --hostname localhost --username root --password mypassword

Output:

17.9% temporary tables created on disk (2.4M on disk / 13.6M total).

States

  • WARN if pct_temp_disk (number of on-disk temporary tables) > 25%

Perfdata / Metrics

Name

Type

Description

mysql_created_tmp_disk_tables

Continous Counter

Number of on-disk temporary tables created.

mysql_created_tmp_tables

Continous Counter

Number of in-memory temporary tables created.

mysql_max_heap_table_size

Bytes

Maximum size in bytes for user-created MEMORY tables.

mysql_max_tmp_table_size

Bytes

max(max_heap_table_size, tmp_table_size)

mysql_pct_temp_disk

Percentage

Created_tmp_disk_tables / Created_tmp_tables * 100

mysql_tmp_table_size

Bytes

The largest size for temporary tables in memory (not MEMORY tables) although if max_heap_table_size is smaller the lower limit will apply.

Credits, License