mysql 5.5半同步

半同步开启

主库

mysql> show variables like '%semi_sync%';

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

| Variable_name                              | Value |

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

| rpl_semi_sync_master_enabled               | ON    |  ON

| rpl_semi_sync_master_timeout               | 1000  |

| rpl_semi_sync_master_trace_level           | 1     |

| rpl_semi_sync_master_wait_no_slave         | ON    |

| rpl_semi_sync_slave_delay_sync_master_info | OFF   |

| rpl_semi_sync_slave_enabled                | ON    |     ON

| rpl_semi_sync_slave_trace_level            | 1     |

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

从库

mysql> show variables like '%semi_sync%';

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

| Variable_name                              | Value |

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

| rpl_semi_sync_master_enabled               | ON    |     ON

| rpl_semi_sync_master_timeout               | 1000  |

| rpl_semi_sync_master_trace_level           | 1     |

| rpl_semi_sync_master_wait_no_slave         | ON    |

| rpl_semi_sync_slave_delay_sync_master_info | OFF   |

| rpl_semi_sync_slave_enabled                | ON    |     ON

| rpl_semi_sync_slave_trace_level            | 1     |

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

异步

主库

mysql> show variables like "%semi_sync%";

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

| Variable_name                              | Value |

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

| rpl_semi_sync_master_enabled               | OFF   |     OFF

| rpl_semi_sync_master_timeout               | 1000  |

| rpl_semi_sync_master_trace_level           | 1     |

| rpl_semi_sync_master_wait_no_slave         | ON    |

| rpl_semi_sync_slave_delay_sync_master_info | OFF   |

| rpl_semi_sync_slave_enabled                | ON    |

| rpl_semi_sync_slave_trace_level            | 1     |

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

从库

mysql> show variables like '%semi_sync%';

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

| Variable_name                              | Value |

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

| rpl_semi_sync_master_enabled               | OFF   |     OFF

| rpl_semi_sync_master_timeout               | 1000  |

| rpl_semi_sync_master_trace_level           | 1     |

| rpl_semi_sync_master_wait_no_slave         | ON    |

| rpl_semi_sync_slave_delay_sync_master_info | OFF   |

| rpl_semi_sync_slave_enabled                | ON    |

| rpl_semi_sync_slave_trace_level            | 1     |

+--------------------------------------------+———+

关闭semi-sync的话，要

rpl_semi_sync_master_enabled  rpl_semi_sync_slave_enabled 都设置成OFF

开启semi-sync的话，要

主库rpl_semi_sync_master_enabled ON, rpl_semi_sync_slave_enabled OFF

备库rpl_semi_sync_master_enabled OFF, rpl_semi_sync_slave_enabled ON