http://blog.chinaunix.net/uid-451-id-3081801.html

配置MySQL半同步复制

1. 安装
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On the master:

mysql> INSTALL PLUGIN rpl_semi_sync_master SONAME 'semisync_master.so';

On each slave:

mysql> INSTALL PLUGIN rpl_semi_sync_slave SONAME 'semisync_slave.so';

2. 必须同时两端激活
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At runtime:

On the master:

SET GLOBAL rpl_semi_sync_master_enabled = 1;
SET GLOBAL rpl_semi_sync_master_timeout = 3000;

On the slave:

SET GLOBAL rpl_semi_sync_slave_enabled = 1;
STOP SLAVE IO_THREAD; START SLAVE IO_THREAD;


3. 监视
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看配置

SHOW VARIABLES LIKE 'rpl_semi_sync%';

看状态:
SHOW STATUS LIKE 'Rpl_semi_sync%';