MySQL复制环境中使用slave_exec_mod参数

http://blog.csdn.net/staricqxyz/article/details/18889143

先看下slave_exec_mod官方描述

Command-Line Format	--slave-exec-mode=mode
Option-File Format	slave_exec_mode
System Variable Name	slave_exec_mode
Variable Scope	Global
Dynamic Variable	Yes
	Permitted Values
Type	enumeration
Default	STRICT (ALL)
Default	IDEMPOTENT (NDB)
Valid Values	IDEMPOTENT
STRICT

Controls whether

IDEMPOTENT

or

STRICT

mode
is used in replication conflict resolution and error checking.

IDEMPOTENT

mode causes suppression
of duplicate-key and no-key-found errors.

This mode is needed for multi-master replication, circular replication, and some other special replication scenarios for MySQL Cluster Replication.

SLAVE@root@test 07:21:41>show variables like 'slave_exec_mode';

+-----------------+--------+

| Variable_name | Value |

+-----------------+--------+

| slave_exec_mode | STRICT |

+-----------------+--------+

1 row in set (0.00 sec)

SLAVE@root@test 07:21:42>

意思是说slave_exec_mod默认是STRICT可选值是IDEMPOTENT，在多主大型复制系统中建议使用IDEMPOTENT值，它避免duplicate-key 和 no-key-found等错误。这个参数是动态的，可以直接修改。

SLAVE@root@test 07:39:58>show variables like 'slave_exec_mode';

+-----------------+------------+

| Variable_name | Value |

+-----------------+------------+

| slave_exec_mode | IDEMPOTENT |

+-----------------+------------+

1 row in set (0.00 sec)

SLAVE@root@test 07:40:09>set global slave_exec_mode='strict';

Query OK, 0 rows affected (0.00 sec)

SLAVE@root@test 07:40:23>show variables like 'slave_exec_mode';

+-----------------+--------+

| Variable_name | Value |

+-----------------+--------+

| slave_exec_mode | STRICT |

+-----------------+--------+

1 row in set (0.00 sec)

SLAVE@root@test 07:40:24>set global slave_exec_mode='IDEMPOTENT';

Query OK, 0 rows affected (0.00 sec)