While slave drift is not a concern, there is no account of schema changes on different hosts due to performance reasons, such as different partitioning system, or usage of the TokuDB engine instead of InnoDB.
Create a script or application to check for unaccounted object differences (tables, triggers, dbs), schema changes in tables and data differences.
While there are open source solutions for that, we need to accommodate those tools to our particular setup:
- Heavy use of filters
- sanitized host with some of the data missing
- Not yet applied or undocumented schema changes (good changes applied to production only but not to mediawiki; changes applied to mediawiki but never scheduled for production; etc.)
Ideally, in the end we will have those checks automatized somehow (not necessarily in a cron). Fix should be manual, but tool-assisted.