MySQL複製環境中使用slave_exec_mod參數

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.

[plain] view plaincopyprint?
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> 

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>
意思是說slave_exec_mod預設是STRICT可選值是IDEMPOTENT，在多主大型複製系統中建議使用IDEMPOTENT值，它避免duplicate-key 和 no-key-found等錯誤。這個參數是動態，可以直接修改。

[plain] view plaincopyprint?
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)