MYSQL GTID 復(fù)制

MySQL5.7以后都基本用GTID方式復(fù)制了，相對(duì)于binlog和position號(hào)方式，在failover時(shí)候減少很多人工切換操作

GTID，global transaction identitifiers，基于全局事務(wù)的復(fù)制方式，由server_uuid:transaction_id組成,server_uuid在數(shù)據(jù)庫啟動(dòng)過程生成,在/data/auto.cnf中

復(fù)制過程：master事務(wù)提交時(shí)GTID，記錄到binlog；然后master的binlog傳送到slave的relaylog,slave讀取GTID生成gtid_next系統(tǒng)參數(shù);slave校驗(yàn)GTID是否在binlog并進(jìn)一步應(yīng)用事務(wù)（5.7后是存放在gtid_executed系統(tǒng)表，這樣不用開啟log_slave_updates參數(shù)，從而不用把relaylog記錄再記錄到binlog，減少slave壓力）

下面操作下：

首先主從都配置gtid_mode、enforce_gtid_consistency參數(shù),其中備庫多加個(gè)log_slave_updates=1

[root@localhost /usr/local/mysql/data]$ cat /etc/my.cnf
[mysqld]
datadir=/usr/local/mysql/data
log_bin=mysql-bin
server_id=1
gtid_mode=on
enforce_gtid_consistency=on
[root@localhost /usr/local/mysql/data]$

mysql> show variables like '%gtid%';
+----------------------------------+-----------+
| Variable_name                    | Value     |
+----------------------------------+-----------+
| binlog_gtid_simple_recovery      | ON        |
| enforce_gtid_consistency         | ON        |
| gtid_executed_compression_period | 1000      |
| gtid_mode                        | ON        |
| gtid_next                        | AUTOMATIC |
| gtid_owned                       |           |
| gtid_purged                      |           |
| session_track_gtids              | OFF       |
+----------------------------------+-----------+
8 rows in set (0.00 sec)

mysql>

然后將之前異步復(fù)制的配置去掉，重新配置slave中主庫信息即可

mysql> show variables like '%log_slave_updates%';
+-------------------+-------+
| Variable_name     | Value |
+-------------------+-------+
| log_slave_updates | ON    |
+-------------------+-------+
1 row in set (0.00 sec)

mysql> stop slave;
Query OK, 0 rows affected (0.01 sec)

mysql> reset slave all;
Query OK, 0 rows affected (0.02 sec)

mysql> change master to
    -> master_host='192.0.1.10',
    -> master_user='scott',
    -> master_password='tiger',
    -> master_port=3306,
    -> master_auto_position=1;
Query OK, 0 rows affected, 2 warnings (0.02 sec)

mysql> start slave;
Query OK, 0 rows affected (0.00 sec)
mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.0.1.10
                  Master_User: scott
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000004
          Read_Master_Log_Pos: 573
               Relay_Log_File: localhost-relay-bin.000002
                Relay_Log_Pos: 786
        Relay_Master_Log_File: mysql-bin.000004
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
              Replicate_Do_DB: 
          Replicate_Ignore_DB: 
           Replicate_Do_Table: 
       Replicate_Ignore_Table: 
      Replicate_Wild_Do_Table: 
  Replicate_Wild_Ignore_Table: 
                   Last_Errno: 0
                   Last_Error: 
                 Skip_Counter: 0
          Exec_Master_Log_Pos: 573
              Relay_Log_Space: 997
              Until_Condition: None
               Until_Log_File: 
                Until_Log_Pos: 0
           Master_SSL_Allowed: No
           Master_SSL_CA_File: 
           Master_SSL_CA_Path: 
              Master_SSL_Cert: 
            Master_SSL_Cipher: 
               Master_SSL_Key: 
        Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
                Last_IO_Errno: 0
                Last_IO_Error: 
               Last_SQL_Errno: 0
               Last_SQL_Error: 
  Replicate_Ignore_Server_Ids: 
             Master_Server_Id: 1
                  Master_UUID: 531fa6d1-627f-11e9-8dc7-000c297887a1
             Master_Info_File: /data/master.info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
           Master_Retry_Count: 86400
                  Master_Bind: 
      Last_IO_Error_Timestamp: 
     Last_SQL_Error_Timestamp: 
               Master_SSL_Crl: 
           Master_SSL_Crlpath: 
           Retrieved_Gtid_Set: 531fa6d1-627f-11e9-8dc7-000c297887a1:1-2
            Executed_Gtid_Set: 531fa6d1-627f-11e9-8dc7-000c297887a1:1-2
                Auto_Position: 1
         Replicate_Rewrite_DB: 
                 Channel_Name: 
           Master_TLS_Version: 
1 row in set (0.00 sec)

mysql>

測(cè)試一下，ok的，主庫狀態(tài)可以看到

mysql> show master status;
+------------------+----------+--------------+------------------+------------------------------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set                        |
+------------------+----------+--------------+------------------+------------------------------------------+
| mysql-bin.000004 |      573 |              |                  | 531fa6d1-627f-11e9-8dc7-000c297887a1:1-2 |
+------------------+----------+--------------+------------------+------------------------------------------+
1 row in set (0.00 sec)

mysql>

將slave中l(wèi)og_slave_updates關(guān)掉，就能看到mysql.gtid_executed表中記錄已執(zhí)行g(shù)tid信息了

mysql> select * from mysql.gtid_executed;
+--------------------------------------+----------------+--------------+
| source_uuid                          | interval_start | interval_end |
+--------------------------------------+----------------+--------------+
| 531fa6d1-627f-11e9-8dc7-000c297887a1 |              1 |            2 |
| 531fa6d1-627f-11e9-8dc7-000c297887a1 |              3 |            3 |
+--------------------------------------+----------------+--------------+
2 rows in set (0.00 sec)

由于是基于事務(wù)的，所以就有了限制條件： create table select的方式在基于行復(fù)制的情況下會(huì)被拆分為創(chuàng)建表和insert數(shù)據(jù)兩個(gè)事件，某些情況下這兩個(gè)事件會(huì)被分配相同GTID導(dǎo)致后面insert數(shù)據(jù)部分被忽略而產(chǎn)生錯(cuò)誤；一個(gè)事務(wù)中既包含InnoDB表又包含MyISAM表會(huì)導(dǎo)致可能產(chǎn)生多個(gè)gtid，或者表在主從庫中存儲(chǔ)引擎不一致都會(huì)產(chǎn)生gtid復(fù)制異常

posted @ 2019-08-16 08:57 九命貓幺閱讀(255) 評(píng)論(0) 收藏舉報(bào)

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MYSQL GTID 復(fù)制

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