MySQL半同步复制实践(2)

做几个简单的测试：主库插入一行数据
mysql> select * from test;
+----+--------+
| id | name  |
+----+--------+
|  1 | 小明  |
+----+--------+
1 row in set (0.00 sec) 
mysql> insert into test values(2,'test');
Query OK, 1 row affected (0.00 sec) #可以看见延迟几乎可以忽略

从库这边，数据正常说明成功了~
12345678 mysql> select * from test;
+----+--------+
| id | name  |
+----+--------+
|  1 | 小明  |
|  2 | test  |
+----+--------+
2 rows in set (0.00 sec)

模拟下从库故障
mysql> stop slave IO_THREAD;
Query OK, 0 rows affected (0.01 sec)

我们再在主从插入数据
mysql> insert into test values(3,'test');
Query OK, 1 row affected (10.01 sec) #插入时间很久，10秒钟，10秒超时后，自动切换回异步复制了
mysql> show global status like '%rpl_semi%';
+--------------------------------------------+-------+
| Variable_name                              | Value |
+--------------------------------------------+-------+
| Rpl_semi_sync_master_clients              | 1    |
| Rpl_semi_sync_master_net_avg_wait_time    | 498  |
| Rpl_semi_sync_master_net_wait_time        | 1495  |
| Rpl_semi_sync_master_net_waits            | 3    |
| Rpl_semi_sync_master_no_times              | 3    |
| Rpl_semi_sync_master_no_tx                | 2    |
| Rpl_semi_sync_master_status                | OFF  | #关闭状态
| Rpl_semi_sync_master_timefunc_failures    | 0    |
| Rpl_semi_sync_master_tx_avg_wait_time      | 799  |
| Rpl_semi_sync_master_tx_wait_time          | 1599  |
| Rpl_semi_sync_master_tx_waits              | 2    |
| Rpl_semi_sync_master_wait_pos_backtraverse | 0    |
| Rpl_semi_sync_master_wait_sessions        | 0    |
| Rpl_semi_sync_master_yes_tx                | 2    |
+--------------------------------------------+-------+
14 rows in set (0.00 sec)

恢复IO线程
mysql> start slave IO_THREAD;
Query OK, 0 rows affected (0.00 sec)
mysql> show global status like '%rpl_semi%';
+--------------------------------------------+-------+
| Variable_name                              | Value |
+--------------------------------------------+-------+
| Rpl_semi_sync_master_clients              | 1    |
| Rpl_semi_sync_master_net_avg_wait_time    | 4526  |
| Rpl_semi_sync_master_net_wait_time        | 18107 |
| Rpl_semi_sync_master_net_waits            | 4    |
| Rpl_semi_sync_master_no_times              | 3    |
| Rpl_semi_sync_master_no_tx                | 2    |
| Rpl_semi_sync_master_status                | ON    | #重新开启了
| Rpl_semi_sync_master_timefunc_failures    | 0    |
| Rpl_semi_sync_master_tx_avg_wait_time      | 799  |
| Rpl_semi_sync_master_tx_wait_time          | 1599  |
| Rpl_semi_sync_master_tx_waits              | 2    |
| Rpl_semi_sync_master_wait_pos_backtraverse | 0    |
| Rpl_semi_sync_master_wait_sessions        | 0    |
| Rpl_semi_sync_master_yes_tx                | 2    |
+--------------------------------------------+-------+
14 rows in set (0.00 sec)