`innodb_buffer_pool_size`

WARNING (2 rules)INFOOK

Rule IDs: bp_001, bp_002, bp_003, bp_008

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 dynamic (Dynamic = Yes). Runtime changes use SET GLOBAL (global scope) or SET SESSION (session scope) — confirm syntax and persistence (SET PERSIST) in the manual.
Default value: 128 MB (134217728) (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_buffer_pool_size
Other vendors: MariaDB KB Percona Docs

What is checked

Rules that reference this variable, with their severity and what each rule detects:

WARNING bp_001: Consider increasing innodb_buffer_pool_size. Aim for 60-80% of available RAM on a dedicated MySQL server.
WARNING bp_002: On a dedicated MySQL server, allocate 60-80% of physical RAM to innodb_buffer_pool_size. Start at ~66% if unsure about resource usage.
INFO bp_003: If the server is under normal workload, the buffer pool may be larger than needed. Monitor over time before reducing.
OK bp_008: Positive check — confirms configuration meets expected thresholds.

Tuning guidance

Recommended actions:
- Consider increasing innodb_buffer_pool_size. Aim for 60-80% of available RAM on a dedicated MySQL server.
- On a dedicated MySQL server, allocate 60-80% of physical RAM to innodb_buffer_pool_size. Start at ~66% if unsure about resource usage.
- If the server is under normal workload, the buffer pool may be larger than needed. Monitor over time before reducing.
Trade-offs: Larger buffer pools improve hit ratio but consume more RAM and increase restart warm-up time. Over-allocating risks OOM or swap. Under-allocating means more disk I/O.

Example

SET GLOBAL innodb_buffer_pool_size = 8589934592; -- 8 GB -- Or in my.cnf: innodb_buffer_pool_size = 8G

Always validate on a non-production instance first. Use SET PERSIST (MySQL 8.0+) for changes that should survive restarts.

Generated from the MySQL Advisor documentation build. Dynamic Yes/No reflects the excerpt aligned with Oracle MySQL 8.4 reference material consumed by this project.