database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-08-31 22:22:30 +03:00
Code Activity

MDEV-6775: Wrong binlog order in parallel replication: Intermediate commit

Browse Source 
The code in binlog group commit around wait_for_commit that controls commit
order, did the wakeup of subsequent commits early, as soon as a following
transaction is put into the group commit queue, but before any such commit has
actually taken place. This causes problems with too early wakeup of
transactions that need to wait for prior to commit, but do not take part in
the binlog group commit for one reason or the other.

This patch solves the problem, by moving the wakeup to happen only after the
binlog group commit is completed.

This requires a new solution to ensure that transactions that arrive later
than the leader are still able to participate in group commit. This patch
introduces a flag wait_for_commit::commit_started. When this is set, a waiter
can queue up itself in the group commit queue.

This way, effectively the wait_for_prior_commit() is skipped only for
transactions that participate in group commit, so that skipping the wait is
safe. Other transactions still wait as needed for correctness.
This commit is contained in:
Kristian Nielsen
2014-11-13 10:31:20 +01:00
parent eec04fb4f6
commit d08b893b39
5 changed files with 250 additions and 136 deletions
Download Patch File Download Diff File Expand all files Collapse all files

49
mysql-test/suite/rpl/r/rpl_parallel.result
View File

@@ -923,6 +923,55 @@ a
32
33
34
*** MDEV-6775: Wrong binlog order in parallel replication ***
DELETE FROM t4;
INSERT INTO t4 VALUES (1,NULL), (3,NULL), (4,4), (5, NULL), (6, 6);
include/save_master_gtid.inc
include/sync_with_master_gtid.inc
include/stop_slave.inc
SET @old_dbug= @@GLOBAL.debug_dbug;
SET GLOBAL debug_dbug="+d,inject_binlog_commit_before_get_LOCK_log";
SET @old_format=@@GLOBAL.binlog_format;
SET GLOBAL binlog_format=ROW;
SET GLOBAL slave_parallel_threads=0;
SET GLOBAL slave_parallel_threads=10;
SET @old_format= @@binlog_format;
SET binlog_format= statement;
SET debug_sync='commit_after_release_LOCK_prepare_ordered SIGNAL master_queued1 WAIT_FOR master_cont1';
UPDATE t4 SET b=NULL WHERE a=6;
SET debug_sync='now WAIT_FOR master_queued1';
SET @old_format= @@binlog_format;
SET binlog_format= statement;
SET debug_sync='commit_after_release_LOCK_prepare_ordered SIGNAL master_queued2';
DELETE FROM t4 WHERE b <= 3;
SET debug_sync='now WAIT_FOR master_queued2';
SET debug_sync='now SIGNAL master_cont1';
SET binlog_format= @old_format;
SET binlog_format= @old_format;
SET debug_sync='RESET';
SELECT * FROM t4 ORDER BY a;
a b
1 NULL
3 NULL
4 4
5 NULL
6 NULL
include/start_slave.inc
SET debug_sync= 'now WAIT_FOR waiting';
SELECT * FROM t4 ORDER BY a;
a b
1 NULL
3 NULL
4 4
5 NULL
6 NULL
SET debug_sync= 'now SIGNAL cont';
include/stop_slave.inc
SET GLOBAL debug_dbug=@old_dbug;
SET GLOBAL binlog_format= @old_format;
SET GLOBAL slave_parallel_threads=0;
SET GLOBAL slave_parallel_threads=10;
include/start_slave.inc
include/stop_slave.inc
SET GLOBAL slave_parallel_threads=@old_parallel_threads;
include/start_slave.inc