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MDEV-6321: close_temporary_tables() in format description event not serialised correctly

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When a master server starts up, it logs a special format_description event at
the start of a new binlog to mark that is has restarted. This is used by a
slave to drop all temporary tables - this is needed in case the master crashed
and did not have a chance to send explicit DROP TEMPORARY TABLE statements to
the slave.

In parallel replication, we need to be careful when dropping the temporary
tables - we need to be sure that no prior events are still executing that
might be using the temporary tables to be dropped, _and_ that no following
events have started executing that might have created new temporary tables
that should not be dropped.

This was not handled correctly, which could cause errors about access to not
existing temporary tables or even crashes. This patch implements that such
format_description events cause serialisation of event execution; all prior
events are executed to completion first, then the format_description event is
executed, dropping temporary tables, then following events are queued for
execution.

Master restarts should be sufficiently infrequent that the resulting loss of
parallelism should be of minimal impact.
This commit is contained in:
Kristian Nielsen
2014-07-02 12:51:45 +02:00
parent bd2117d154
commit 4cb1e0eea0
5 changed files with 279 additions and 0 deletions
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86
mysql-test/suite/rpl/r/rpl_parallel_temptable.result Normal file
View File

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include/rpl_init.inc [topology=1->2]
*** MDEV-6321: close_temporary_tables() in format description event not serialised correctly ***
SET @old_parallel_threads=@@GLOBAL.slave_parallel_threads;
include/stop_slave.inc
SET GLOBAL slave_parallel_threads=5;
CHANGE MASTER TO master_use_gtid= current_pos;
include/start_slave.inc
CREATE TABLE t1 (a INT PRIMARY KEY, b VARCHAR(100) CHARACTER SET utf8);
include/stop_slave.inc
SET gtid_domain_id= 1;
INSERT INTO t1 VALUES (1, 0);
CREATE TEMPORARY TABLE t2 (a int);
SET gtid_domain_id= 2;
CREATE TEMPORARY TABLE t3 (a INT PRIMARY KEY);
CREATE TEMPORARY TABLE t4 (a int);
INSERT INTO t3 VALUES (100);
INSERT INTO t4 SELECT a+1 FROM t3;
INSERT INTO t2 VALUES (2), (4), (6), (8), (10), (12), (14), (16), (18), (20);
INSERT INTO t2 VALUES (3), (6), (9), (12), (15), (18);
INSERT INTO t2 VALUES (4), (8), (12), (16), (20);
INSERT INTO t3 SELECT a+2 FROM t4;
INSERT INTO t4 SELECT a+4 FROM t3;
INSERT INTO t2 VALUES (5), (10), (15), (20);
INSERT INTO t2 VALUES (6), (12), (18);
INSERT INTO t2 VALUES (7), (14);
INSERT INTO t2 VALUES (8), (16);
INSERT INTO t2 VALUES (9), (18);
INSERT INTO t2 VALUES (10), (20);
INSERT INTO t3 SELECT a+8 FROM t4;
INSERT INTO t4 SELECT a+16 FROM t3;
INSERT INTO t2 VALUES (11);
INSERT INTO t2 VALUES (12);
INSERT INTO t2 VALUES (13);
INSERT INTO t3 SELECT a+32 FROM t4;
INSERT INTO t2 VALUES (14);
INSERT INTO t2 VALUES (15);
INSERT INTO t2 VALUES (16);
INSERT INTO t4 SELECT a+64 FROM t3;
INSERT INTO t2 VALUES (17);
INSERT INTO t2 VALUES (18);
INSERT INTO t2 VALUES (19);
INSERT INTO t3 SELECT a+128 FROM t4;
INSERT INTO t2 VALUES (20);
INSERT INTO t1 SELECT a, a MOD 7 FROM t3;
INSERT INTO t1 SELECT a, a MOD 7 FROM t4;
INSERT INTO t1 SELECT a, COUNT(*) FROM t2 GROUP BY a;
FLUSH TABLES;
SET SESSION debug_dbug="+d,crash_dispatch_command_before";
SELECT 1;
Got one of the listed errors
INSERT INTO t1 VALUES (0, 1);
include/start_slave.inc
SELECT * FROM t1 WHERE a <= 20 ORDER BY a;
a b
0 1
1 0
2 1
3 1
4 2
5 1
6 3
7 1
8 3
9 2
10 3
11 1
12 5
13 1
14 3
15 3
16 4
17 1
18 5
19 1
20 5
SELECT COUNT(*) FROM t1 WHERE a BETWEEN 100+0 AND 100+256;
COUNT(*)
55
SHOW STATUS LIKE 'Slave_open_temp_tables';
Variable_name Value
Slave_open_temp_tables 0
include/stop_slave.inc
SET GLOBAL slave_parallel_threads=@old_parallel_threads;
include/start_slave.inc
DROP TABLE t1;
include/rpl_end.inc