Hi, Oleksandr! On Mar 09, Oleksandr Byelkin wrote:

revision-id: dc3d6c9edb3536e5f0c87ac1e9c04891d50fc420 (mariadb-10.2.13-32-gdc3d6c9edb3) parent(s): 6cf25e5eb76923550173a0059036d80c80a053d6 author: Oleksandr Byelkin committer: Oleksandr Byelkin timestamp: 2018-03-09 14:39:40 +0100 message:

MDEV-15477: SESSION_SYSVARS_TRACKER does not track last_gtid

register changes of last_gtid

diff --git a/mysql-test/t/session_tracker_last_gtid.test b/mysql-test/t/session_tracker_last_gtid.test --- /dev/null +++ b/mysql-test/t/session_tracker_last_gtid.test @@ -0,0 +1,18 @@ + +--source include/have_innodb.inc +--source include/have_binlog_format_mixed_or_statement.inc

Why "mixed or statement"?

diff --git a/sql/log.cc b/sql/log.cc --- a/sql/log.cc +++ b/sql/log.cc @@ -5945,7 +5945,20 @@ MYSQL_BIN_LOG::write_gtid_event(THD *thd, bool standalone, } if (err) DBUG_RETURN(true); + bool changed_gtid= (thd->last_commit_gtid.seq_no != gtid.seq_no); thd->last_commit_gtid= gtid; + if (changed_gtid && + thd->session_tracker.get_tracker(SESSION_SYSVARS_TRACKER)->is_enabled()) + { + sys_var *svar; + mysql_mutex_lock(&LOCK_plugin); + if ((svar= find_sys_var_ex(thd, "last_gtid", + sizeof("last_gtid") - 1, + false, true))) + thd->session_tracker.get_tracker(SESSION_SYSVARS_TRACKER)-> + mark_as_changed(thd, (LEX_CSTRING*)svar); + mysql_mutex_unlock(&LOCK_plugin); + }

No, please. You svar will always be Sys_last_gtid. There is no need to search for it on every write_gtid_event(), under a mutex. See in sys_vars.cc around Sys_autocommit how to do it easier. Also, perhaps it'd be safer to rename last_commit_gtid to m_last_commit_gtid, make it private and provide a setter and a getter. The setter will update the tracker. I'll make sure that last_commit_gtid is not changed anywhere else bypassing the tracker. Regards, Sergei Chief Architect MariaDB and security@mariadb.org