wsrep XID is checkpointed in innodb rollback segment during transaction commit, and this checkpointing is supposed to happen in strict GTID sequence order.
MDEV-23851 under highly conflicting multi-master work loads, it was observed that Xid checkpointing order can be violated in two scenarios:
- if MariaDB is configured with binlogging enabled but with log_slave_updates = OFF, fairly frequent Xid checkpoint ordering violating happens
- write sets, which failed in certification can perform Xid checkpointing too early in receiving nodes
These Xid checkpointing failures do not cause the issue with
MDEV-23851, but they make troubleshooting MDEV-23851 harder by hiding the underlying issue