innodb_purge_threads
INFO
Rule IDs: mi_004
Overview
- Purpose
- Documented in the MySQL 8.4 manual as a server system variable (scope: Global). Purpose and semantics are described at the linked manual page.
- Dynamic (MySQL 8.4 reference)
- MySQL 8.4 marks this variable as not dynamic (
Dynamic= No). It must be set inmy.cnfor on the command line; changing it requires a restart. - Default value
- 4 (MySQL 8.4)
- Version and product notes
- MariaDB and Percona Server may use different names, defaults, or dynamic behavior; verify their documentation.
- Documentation
- https://dev.mysql.com/doc/refman/8.4/en/innodb-parameters.html#sysvar_innodb_purge_threads
- Other vendors
What is checked
Rules that reference this variable, with their severity and what each rule detects:
- INFO
mi_004: Set innodb_purge_threads=4 (MySQL 8.0 default). Increase if history list length grows consistently.
Tuning guidance
- Recommended actions:
- Set innodb_purge_threads=4 (MySQL 8.0 default). Increase if history list length grows consistently.
- Trade-offs: Validate recommendations against monitoring, workload profiles, and vendor documentation before making changes.
Example
Configure in my.cnf (or equivalent) or server startup options, then restart.