Concepts·MySQL
MySQL Health Checks
Seven counters that describe a server's health, and the two that quietly predict trouble: temporary tables spilling to disk, and joins running with no index at all.
Monitoring and Operations Guide 41 of 45 Intermediate
- OSUbuntu 26.04 LTS
- MySQL8.4.10-0ubuntu0.26.04.1
- Topologydb-a01 source, db-b01 and db-c01 replicas
- TimeAbout 13 min
All of these are cumulative since startup. A monitoring system should record deltas; a single reading tells you almost nothing.
| Server Name | IP Address | OS | Roles | CPU | RAM | HDD |
|---|---|---|---|---|---|---|
| db-a01 | 192.168.0.81 | Ubuntu 26.04 LTS | Primary / Source / Replica Set Member 1 | 2 Core | 4 GB | 50 GB |
This guide includes
Use this when you need a quick read on a server's health. This matters because seven counters describe it - and two of them quietly predict trouble that none of the others show.
- reading Uptime first, since it is the denominator for everything else
- reading the seven counters that describe the server's health
- finding the two that quietly predict trouble
Before you start
- Access to
performance_schemaon db-a01.
-
Read the seven numbers worth watching