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MySQL 并行复制从库更新的记录不存在实际却存在

程序员文章站 2022-06-24 21:51:03
并行复制从库更新的记录不存在实际却存在 背景 开了并行复制的半同步从库SQL 线程报1032错误,异步复制从库没有报错,偶尔会出现这种 分析 版本mysql 5.7.16 mysql show variables like '%slave_para%'; + + + | Variable_name ......

并行复制从库更新的记录不存在实际却存在

背景

开了并行复制的半同步从库SQL 线程报1032错误,异步复制从库没有报错,偶尔会出现这种

分析

版本mysql 5.7.16
mysql> show variables like '%slave_para%';
+------------------------+---------------+
| Variable_name | Value |
+------------------------+---------------+
| slave_parallel_type | LOGICAL_CLOCK |
| slave_parallel_workers | 16 |
+------------------------+---------------+
1、疑是对从库执行了更新操作,导致更新的记录不存在
2、查看error log发现

2018-04-03T10:11:47.720156+08:00 16 [ERROR] Slave SQL for channel '': Worker 13 failed executing transaction 'a272bbcf-874f-11e7-a288-00505695b721:687871861' at master log mysql-bin.004119, end_log_pos 376471678; Could not execute Update_rows event on table anytxn.seq_xxxx; Can't find record in 'seq_xxxx', Error_code: 1032; handler error HA_ERR_END_OF_FILE; the event's master log mysql-bin.004119, end_log_pos 376471678, Error_code: 1032

2018-04-03T10:11:47.720230+08:00 2 [Warning] Slave SQL for channel '': ... The slave coordinator and worker threads are stopped, possibly leaving data in inconsistent state. A restart should restore consistency automatically, although using non-transactional storage for data or info tables or DDL queries could lead to problems. In such cases you have to examine your data (see documentation for details). Error_code: 1756
2018-04-03T10:11:47.720959+08:00 2 [Note] Error reading relay log event for channel '': slave SQL thread was killed

3、从 SQL线程停止的position分析binlog发现

SET @@SESSION.GTID_NEXT= 'a272bbcf-874f-11e7-a288-00505695b721:687871861'/*!*/;
# at 376471694
#180403 10:11:47 server id 104073  end_log_pos 376471555 CRC32 0x1be91176   Query   thread_id=2086049   exec_time=0 error_code=0
SET TIMESTAMP=1522721507/*!*/;
BEGIN
/*!*/;
# at 376471768
#180403 10:11:47 server id 104073  end_log_pos 376471616 CRC32 0x10644d77   Table_map: `anytxn`.`seq_xxxx` mapped to number 301
# at 376471829
#180403 10:11:47 server id 104073  end_log_pos 376471678 CRC32 0x871a9787   Update_rows: table id 301 flags: STMT_END_F

### UPDATE `anytxn`.`seq_xxxx`
### WHERE
###   @1=7116088 /* LONGINT meta=0 nullable=0 is_null=0 */
###   @2=1 /* INT meta=0 nullable=0 is_null=0 */
### SET
###   @1=7116089 /* LONGINT meta=0 nullable=0 is_null=0 */
###   @2=1 /* INT meta=0 nullable=0 is_null=0 */
# at 376471891
#180403 10:11:47 server id 104073  end_log_pos 376471709 CRC32 0x9eb59238   Xid = 22247621418
COMMIT/*!*/;
# at 376471922
#180403 10:11:47 server id 104073  end_log_pos 376471774 CRC32 0xf7b6ad5d   GTID    last_committed=641254   sequence_number=641259
SET @@SESSION.GTID_NEXT= 'a272bbcf-874f-11e7-a288-00505695b721:687871862'/*!*/;
# at 376471987
#180403 10:11:47 server id 104073  end_log_pos 376471856 CRC32 0x6256de00   Query   thread_id=2085350   exec_time=0 error_code=0
SET TIMESTAMP=1522721507/*!*/;
BEGIN
/*!*/;
# at 376472069
#180403 10:11:47 server id 104073  end_log_pos 376471979 CRC32 0x6c329578   Table_map: `anytxn`.`bm_cc_customer_address_info` mapped to number 1569
# at 376472192
#180403 10:11:47 server id 104073  end_log_pos 376472162 CRC32 0x834cc8b9   Write_rows: table id 1569 flags: STMT_END_F


### INSERT INTO `anytxn`.`bm_xxxxxxxxxxxxxx`
### SET
###   @1=14480779 /* LONGINT meta=0 nullable=0 is_null=0 */
###   @2='0000001002380654' /* STRING(96) meta=65120 nullable=0 is_null=0 */
###   @3='B001' /* VARSTRING(30) meta=30 nullable=1 is_null=0 */
###   @4=NULL /* STRING(12) meta=65036 nullable=1 is_null=1 */
###   @5='10000010001202000000001' /* VARSTRING(96) meta=96 nullable=1 is_null=0 */
###   @6='B00' /* STRING(9) meta=65033 nullable=1 is_null=0 */
###   @7='xxxxxxxxxxx' /* VARSTRING(765) meta=765 nullable=1 is_null=0 */
###   @8=NULL /* STRING(18) meta=65042 nullable=1 is_null=1 */
###   @9=NULL /* STRING(18) meta=65042 nullable=1 is_null=1 */
###   @10=NULL /* STRING(18) meta=65042 nullable=1 is_null=1 */
 mysql@ACSXFDB6.xwbank.com:/home/mysql>  mysqlbinlog -v -v --start-datetime='2018-04-03 10:11:45' --stop-datetime='2018-04-03 10:11:48'  /data/mysql/ACSXFDB6-relay-bin.005477 | grep last_comm | grep 10:11:47 | grep 641254
#180403 10:11:47 server id 104073  end_log_pos 376469618 CRC32 0xb6dc6cef   GTID    last_committed=641227   sequence_number=641254
#180403 10:11:47 server id 104073  end_log_pos 376471774 CRC32 0xf7b6ad5d   GTID    last_committed=641254   sequence_number=641259
#180403 10:11:47 server id 104073  end_log_pos 376472258 CRC32 0x27cf3013   GTID    last_committed=641254   sequence_number=641260

从上面信息可以看出,发生更新记录不存在是在更新anytxn.seq_xxxx表的标识为7116088 的记录
有两个并发提交的事务last_committed=641254 ,与发现更新的记录不存在的 687871861 事务还有提交的事务 sequence_number=641260(即insert另一张表的操作)

4、查看更新的记录不存在的表和相关记录

show create table seq_xxxx;
| seq_xxxx | CREATE TABLE seq_xxxx (
currentValue bigint(20) NOT NULL,
increment int(11) NOT NULL DEFAULT '1'

mysql> select * from seq_xxxx;
+--------------+-----------+
| currentValue | increment |
+--------------+-----------+
| 7116088 | 1 |
+--------------+-----------+
可以发现实际数据库中是存在该记录的

测试

mysql> select @@version;
+------------+
| @@version |
+------------+
| 5.7.19-log |
+------------+
1 row in set (0.00 sec)
mysql> show variables like '%para%';
+------------------------+---------------+
| Variable_name | Value |
+------------------------+---------------+
| slave_parallel_type | LOGICAL_CLOCK |
| slave_parallel_workers | 4 |
+------------------------+---------------+

sysbench /usr/share/sysbench/tests/include/oltp_legacy/oltp.lua --mysql-host=10.186.30.73 --mysql-socket=/opt/mysql/data/3307/mysqld.sock --mysql-port=3307  --db-driver=mysql  --mysql-db=test --mysql-user=admin --mysql-password=admin --table_size=100000 --tables=5 --threads=100 --time=120 --report-interval=5  run

有并发提交的事务,但没有模拟重现出更新的记录不存在,但在库中却存在的情况
MySQL 并行复制从库更新的记录不存在实际却存在

相关bug链接
Repeated multi-threaded slave replication failures