Werk #22756: MySQL Connections: incomplete agent data

Component

Checks & agents

Title

MySQL Connections: incomplete agent data

Date

Oct 16, 2026

Level

Trivial Change

Class

Bug Fix

Compatibility

Compatible - no manual interaction needed

Checkmk versions & editions

3.0.0b1 Not yet released	Checkmk Community, Checkmk Pro, Checkmk Ultimate, Checkmk Cloud, Checkmk Ultimate MT
2.5.0p17 Not yet released	Checkmk Community, Checkmk Pro, Checkmk Ultimate, Checkmk Cloud, Checkmk Ultimate MT
2.4.0p38 Not yet released	Checkmk Community, Checkmk Pro, Checkmk Ultimate, Checkmk Cloud, Checkmk Ultimate MT

If the agent output of a MySQL or MariaDB instance lacked the server variable max_connections, for example because querying the server variables failed in one check cycle, the MySQL Connections service crashed with KeyError: 'max_connections'.

The service now goes to UNKNOWN and names the missing values, for example Connection information is missing: max_connections. This message replaces the previous, unspecific Connection information is missing.

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