Hi, Andrei, On Mar 01, Andrei Elkin wrote:

...

On Feb 28, Andrei wrote:

...

revision-id: 880e92a48ba (mariadb-10.6.6-16-g880e92a48ba) parent(s): 4030a9fb2eb author: Andrei committer: Andrei timestamp: 2022-02-21 14:58:13 +0200 message:

MDEV-27760 event may non stop replicate in circular semisync setup

diff --git a/sql/slave.cc b/sql/slave.cc index c0eef02ca7a..a1f4f4f0081 100644 --- a/sql/slave.cc +++ b/sql/slave.cc @@ -6186,13 +6186,13 @@ static int queue_event(Master_info* mi, const uchar *buf, ulong event_len) bool is_rows_event= false; /* The flag has replicate_same_server_id semantics and is raised to accept - a same-server-id event on the semisync slave, for both the gtid and legacy - connection modes. - Such events can appear as result of this server recovery so the event - was created there and replicated elsewhere right before the crash. At recovery - it could be evicted from the server's binlog. - */ - bool do_accept_own_server_id= false; + a same-server-id event group by the gtid strict mode semisync slave. + Own server-id events can appear as result of this server crash-recovery: + the transaction was created on this server then being master, got replicated + elsewhere right before the crash before commit; + finally at recovery the transaction gets evicted from the server's binlog. + */ + static bool do_accept_own_server_id= false;

No, sorry, it cannot be static. If you need to preserve it between events, you can keep it, for example, in Master_info.

The var is set by Gtid events to serve as a marker of the whole current Gtid-headed group of event. Only next Gtid event may change the current value.

Why can't it?

Why it cannot be static? Because it's not a property of the server, it's a property of a specific replication stream. Technically one can have a multi-source and do_accept_own_server_id could have different values for different masters.

...

So, the question now is, why do you need to preserve the value of do_accept_own_server_id between queue_event invocations?

The flag as said above applies to the whole group of events, so it's preserved at least through so many queue_event() calls as many event in the group (I count Gtid itself in).

As far as I can see, you can calculate it for every event just the same.

...

...

@@ -6281,6 +6281,8 @@ static int queue_event(Master_info* mi, const uchar *buf, ulong event_len) dbug_rows_event_count = 0; };); #endif + s_id= uint4korr(buf + SERVER_ID_OFFSET); + mysql_mutex_lock(&mi->data_lock);

switch (buf[EVENT_TYPE_OFFSET]) { @@ -6722,6 +6724,11 @@ static int queue_event(Master_info* mi, const uchar *buf, ulong event_len)

++mi->events_queued_since_last_gtid; inc_pos= event_len; + + do_accept_own_server_id= + (s_id == global_system_variables.server_id && rpl_semi_sync_slave_enabled + && mi->using_gtid != Master_info::USE_GTID_NO && opt_gtid_strict_mode) ? + true : false;

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