group_replication_single_primary_mode
INFO
1 automated check cover this variable.
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 useSET GLOBAL(global scope) orSET SESSION(session scope) — confirm syntax and persistence (SET PERSIST) in the manual. - Default value
- Default depends on MySQL version, build, and platform — see the manual page for this variable.
- 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/group-replication-system-variables.html#sysvar_group_replication_single_primary_mode
- Other vendors
What is checked
Rules that reference this variable, with their severity and what each rule detects:
- INFO Multi-primary mode requires careful conflict avoidance in the application (no hot rows, no cross-member write conflicts). Single-primary mode is recommended for most workloads.
Tuning guidance
- Recommended actions:
- Multi-primary mode requires careful conflict avoidance in the application (no hot rows, no cross-member write conflicts). Single-primary mode is recommended for most workloads.
- Trade-offs: Validate recommendations against monitoring, workload profiles, and vendor documentation before making changes.
Example
Consult the manual for whether SET GLOBAL, SET PERSIST, or SET SESSION applies.