MySQL 5.6主从复制第三部分[把从服务器提升为主服务器]

MySQL 5.6主从复制第三部分[把从服务器提升为主服务器]

第三部分测试主服务器挂掉，提升某个从服务器的情况。

继续用mysql::sandbox来测试。

主服务器(别名black)(server-id:1)安装在 /home/modify/sandboxes/msb_5_6_10/ 使用5610端口。

从服务器(别名blue)(server-id:2)安装在 /home/modify/sandboxes/msb_5_6_10_a/ 使用5611端口。

从服务器(别名green)(server-id:3)安装在 /home/modify/sandboxes/msb_5_6_10_b/ 使用5612端口。

从服务器(别名red)(server-id:4)安装在 /home/modify/sandboxes/msb_5_6_10_c/ 使用5613端口。

MySQL 5.6主从复制第一部分[简介及配置]

MySQL 5.6主从复制第二部分[恢复某一台从服务器]

MySQL 5.6主从复制第三部分[把从服务器提升为主服务器]

MySQL 5.6主从复制第四部分[一些被忽视的操作细节]

MySQL 主从复制事件校验 MySQL Replication Event Checksum

使用pt-table-checksum检查主从复制是否正常

----------------------------------------分割线----------------------------------------

然后再构造一种最特殊的情况：

当主服务器挂掉的时候，blue获取到的gtid及transaction比green要少， green比red要少，然后要求把green提升为主服务器。

主black 写入一条数据:
mysql [localhost] {msandbox} (test) > SHOW CREATE TABLE t;
+-------+-------------------------------------------------------------------------------------+
| TABLE | CREATE TABLE                                                                        |
+-------+-------------------------------------------------------------------------------------+
| t     | CREATE TABLE `t` (
  `id` INT(11) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8 |
+-------+-------------------------------------------------------------------------------------+
1 ROW IN SET (0.00 sec)
 
mysql [localhost] {msandbox} (test) > INSERT INTO t SET id=1;
Query OK, 1 ROW affected (0.00 sec)
mysql [localhost] {msandbox} (test) > SHOW master STATUS;
+------------------+----------+--------------+------------------+-------------------------------------------+
| File             | POSITION | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set                         |
+------------------+----------+--------------+------------------+-------------------------------------------+
| black-bin.000002 |     6771 |              |                  | 05b47d41-7b10-11e2-9fff-00241db92e69:1-30 |
+------------------+----------+--------------+------------------+-------------------------------------------+
1 ROW IN SET (0.00 sec)
 
 
从blue:
获取到gtid:30之后，就停止复制：
mysql [localhost] {msandbox} (test) > SHOW slave STATUS\G
......
......
           Retrieved_Gtid_Set: 05b47d41-7b10-11e2-9fff-00241db92e69:16-30
            Executed_Gtid_Set: 05b47d41-7b10-11e2-9fff-00241db92e69:1-30
                Auto_Position: 1
 
mysql [localhost] {msandbox} (test) > stop slave;
Query OK, 0 ROWS affected (0.00 sec)
 
主black 继续写入一条数据:
mysql [localhost] {msandbox} (test) > INSERT INTO t SET id=2;
Query OK, 1 ROW affected (1.27 sec)
 
mysql [localhost] {msandbox} (test) > SHOW master STATUS;
+------------------+----------+--------------+------------------+-------------------------------------------+
| File             | POSITION | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set                         |
+------------------+----------+--------------+------------------+-------------------------------------------+
| black-bin.000002 |     7141 |              |                  | 05b47d41-7b10-11e2-9fff-00241db92e69:1-31 |
+------------------+----------+--------------+------------------+-------------------------------------------+
1 ROW IN SET (0.00 sec)
 
从green:
获取到gtid:31之后，停止复制：
mysql [localhost] {msandbox} (test) > SHOW slave STATUS\G
.......
.......
           Retrieved_Gtid_Set: 05b47d41-7b10-11e2-9fff-00241db92e69:18-31
            Executed_Gtid_Set: 05b47d41-7b10-11e2-9fff-00241db92e69:1-31
                Auto_Position: 1
 
mysql [localhost] {msandbox} (test) > stop slave;
Query OK, 0 ROWS affected (0.00 sec)
 
主black 继续写入一条数据:
mysql [localhost] {msandbox} (test) > INSERT INTO t SET id=3;
Query OK, 1 ROW affected (0.00 sec)
 
mysql [localhost] {msandbox} (test) > SHOW master STATUS;
+------------------+----------+--------------+------------------+-------------------------------------------+
| File             | POSITION | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set                         |
+------------------+----------+--------------+------------------+-------------------------------------------+
| black-bin.000002 |     7511 |              |                  | 05b47d41-7b10-11e2-9fff-00241db92e69:1-32 |
+------------------+----------+--------------+------------------+-------------------------------------------+
1 ROW IN SET (0.00 sec)
 
从red:
获取到gtid:32之后，停止复制：
mysql [localhost] {msandbox} (test) > SHOW slave STATUS\G
......
......
           Retrieved_Gtid_Set: 05b47d41-7b10-11e2-9fff-00241db92e69:20-32
            Executed_Gtid_Set: 05b47d41-7b10-11e2-9fff-00241db92e69:1-32
                Auto_Position: 1
 
 
关闭主black:
[MODIFY@H209 msb_5_6_10]$ ./stop 
 
三台从服务器都START slave:
mysql [localhost] {msandbox} (test) > START slave;
Query OK, 0 ROWS affected, 1 warning (0.00 sec)
 
现在slave的状态应该是IO thread在connecting black(5610端口)，但是连接失败。 SQL thread应该是正常的:
mysql [localhost] {msandbox} (test) > SHOW slave STATUS \G
*************************** 1. ROW ***************************
               Slave_IO_State: Connecting TO master
                  Master_Host: 127.0.0.1
                  Master_User: repl_user
                  Master_Port: 5610
                Connect_Retry: 60
              Master_Log_File: black-bin.000001
          Read_Master_Log_Pos: 1809
               Relay_Log_File: mysql_sandbox5613-relay-bin.000002
                Relay_Log_Pos: 1382
        Relay_Master_Log_File: black-bin.000001
             Slave_IO_Running: Connecting
            Slave_SQL_Running: Yes
			......
			......
                Last_IO_Errno: 2003
                Last_IO_Error: error connecting TO master 'repl_user@127.0.0.1:5610' - retry-TIME: 60  retries: 1
               Last_SQL_Errno: 0
               Last_SQL_Error:

场景构造完毕。