gtid_mode
WARNING
Rule IDs: bl_010
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
- OFF (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/replication-options-gtids.html#sysvar_gtid_mode
- Other vendors
What is checked
Rules that reference this variable, with their severity and what each rule detects:
- WARNING
bl_010: Always set enforce_gtid_consistency=ON when gtid_mode=ON.
Tuning guidance
- Recommended actions:
- Always set enforce_gtid_consistency=ON when gtid_mode=ON.
- Trade-offs: Binary logging is essential for replication and point-in-time recovery. sync_binlog=1 guarantees durability but adds fsync overhead. ROW format is safest for replication consistency but produces larger binlogs.
Example
-- Enable GTID (requires planned transition):
SET GLOBAL gtid_mode = OFF_PERMISSIVE;
SET GLOBAL gtid_mode = ON_PERMISSIVE;
SET GLOBAL enforce_gtid_consistency = ON;
SET GLOBAL gtid_mode = ON;
Always validate on a non-production instance first. Use SET PERSIST (MySQL 8.0+) for changes that should survive restarts.