Hi, Andrei! On Jan 10, Andrei Elkin wrote:

revision-id: 9ea85a70a75 (mariadb-10.2.40-4-g9ea85a70a75) parent(s): 160d97a4aaa author: Andrei Elkin committer: Andrei Elkin timestamp: 2021-08-08 14:20:57 +0300 message:

MDEV-24654 GTID event falsely marked transactional

GTID event can be falsely marked transactional in few cases including binary-logging on the slave side upon execution. In some execution branches bin-logging of non-transactional events can be done through transactional cache. E.g see comments in THD::binlog_write_table_map().

I saw that and still couldn't understand why bin-logging of non-transactional events can be done through transactional cache.

In order to not create the false 'trans' tag the fact of Xid event logging is checked to compute correct argument to Gtid_log_event ctor.

This is wrong. Transactions only end with a Xid event if all participating engines support XA. Try to create an InnoDB+FederatedX transaction (I just did) and it'll end with Query_log_event("COMMIT")

diff --git a/sql/log.cc b/sql/log.cc index 1d9b4645421..7fef2e0d739 100644 --- a/sql/log.cc +++ b/sql/log.cc @@ -8118,9 +8118,11 @@ MYSQL_BIN_LOG::write_transaction_or_stmt(group_commit_entry *entry, uint64 commit_id) { binlog_cache_mngr *mngr= entry->cache_mngr; + bool has_xid= entry->end_event->get_type_code() == XID_EVENT; DBUG_ENTER("MYSQL_BIN_LOG::write_transaction_or_stmt");

- if (write_gtid_event(entry->thd, false, entry->using_trx_cache, commit_id)) + if (write_gtid_event(entry->thd, false, + entry->using_trx_cache && has_xid, commit_id)) DBUG_RETURN(ER_ERROR_ON_WRITE);

if (entry->using_stmt_cache && !mngr->stmt_cache.empty() &&

Regards, Sergei VP of MariaDB Server Engineering and security@mariadb.org