1、什么是GTID?
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1、全局唯一,一個(gè)事務(wù)對(duì)應(yīng)一個(gè)GTID 2、替代傳統(tǒng)的binlog+pos復(fù)制;使用master_auto_position=1自動(dòng)匹配GTID斷點(diǎn)進(jìn)行復(fù)制 3、MySQL5.6開始支持 4、在傳統(tǒng)的主從復(fù)制中,slave端不用開啟binlog;但是在GTID主從復(fù)制中,必須開啟binlog 5、slave端在接受master的binlog時(shí),會(huì)校驗(yàn)GTID值 6、為了保證主從數(shù)據(jù)的一致性,多線程同時(shí)執(zhí)行一個(gè)GTID
2、組成
Master_UUID:序列號(hào)
舉例:
ceb0ca3d-8366-11e8-ad2b-000c298b7c9a:1-5
ceb0ca3d-8366-11e8-ad2b-000c298b7c9a其實(shí)就是master的uuid值;1-5是序列號(hào),每次一個(gè)事務(wù)完成都會(huì)自增1,也就是說下一次為1-6。
3、工作原理
1、master更新數(shù)據(jù)時(shí),會(huì)在事務(wù)前產(chǎn)生GTID,一同記錄到binlog日志中。 2、slave端的i/o 線程將變更的binlog,寫入到本地的relay log中。 3、sql線程從relay log中獲取GTID,然后對(duì)比slave端的binlog是否有記錄。 4、如果有記錄,說明該GTID的事務(wù)已經(jīng)執(zhí)行,slave會(huì)忽略。 5、如果沒有記錄,slave就會(huì)從relay log中執(zhí)行該GTID的事務(wù),并記錄到binlog。 6、在解析過程中會(huì)判斷是否有主鍵,如果沒有就用二級(jí)索引,如果沒有就用全部掃描
4、GTID主從配置
版本:MySQL5.7
配置master
vim /etc/my.cnf [client] socket=/usr/local/mysql/mysql.sock [mysqld] basedir=/usr/local/mysql datadir=/usr/local/mysql/data user=mysql pid-file=/usr/local/mysql/data/mysqld.pid log-error=/usr/local/mysql/data/mysql.err socket=/usr/local/mysql/mysql.sock port=3306 server-id=1 gtid-mode=ON enforce-gtid-consistency=ON server-id=1 binlog_format=row log-bin=/usr/local/mysql/data/mysql-bin systemctl restart mysqld firewall-cmd --add-port=3306/tcp --permanent firewall-cmd --reload
配置slave
vim /etc/my.cnf [client] socket=/usr/local/mysql/mysql.sock [mysqld] basedir=/usr/local/mysql datadir=/usr/local/mysql/data user=mysql pid-file=/usr/local/mysql/data/mysqld.pid log-error=/usr/local/mysql/data/mysql.err socket=/usr/local/mysql/mysql.sock port=3306 server-id=2 gtid-mode=ON enforce-gtid-consistency=ON server-id=2 binlog_format=ROW log-bin=/usr/local/mysql/data/mysql-bin log_slave_updates=ON skip-slave-start=1 systemctl restart mysqld firewall-cmd --add-port=3306/tcp --permanent firewall-cmd --reload
master授權(quán)配置
mysql -uroot -p mysql> grant replication slave on *.* to 'rep'@'10.0.0.%' identified by '123'; mysql> flush privileges;
slave配置同步
mysql -uroot -p mysql> change master to master_host='10.0.0.132', master_user='rep',master_password='123',master_port=3306,master_auto_position=1; mysql> start slave;
查看slave的狀態(tài)
mysql> show slave status\G; *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 10.0.0.132 Master_User: rep Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000003 Read_Master_Log_Pos: 635 Relay_Log_File: slave-relay-bin.000005 Relay_Log_Pos: 848 Relay_Master_Log_File: mysql-bin.000003 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: 635 Relay_Log_Space: 1308 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: ceb0ca3d-8366-11e8-ad2b-000c298b7c9a Master_Info_File: /usr/local/mysql/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: ceb0ca3d-8366-11e8-ad2b-000c298b7c9a:1-4 Executed_Gtid_Set: ceb0ca3d-8366-11e8-ad2b-000c298b7c9a:1-4 Auto_Position: 1 Replicate_Rewrite_DB: Channel_Name: Master_TLS_Version: 1 row in set (0.00 sec)
出現(xiàn)這兩個(gè)yes表示同步成功
通過slave的狀態(tài)信息,可以看到GTID的值、Matser_UUID等信息
查看master狀態(tài)
mysql> show master status; +------------------+----------+--------------+------------------+------------------------------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set | +------------------+----------+--------------+------------------+------------------------------------------+ | mysql-bin.000003 | 635 | | | ceb0ca3d-8366-11e8-ad2b-000c298b7c9a:1-4 | +------------------+----------+--------------+------------------+------------------------------------------+ 1 row in set (0.00 sec)
注意對(duì)比slave端,Executed_Gtid_Set的值應(yīng)該是一樣的。
5、驗(yàn)證主從
master上
mysql> create database test01; Query OK, 1 row affected (0.00 sec) mysql> show master status; +------------------+----------+--------------+------------------+------------------------------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set | +------------------+----------+--------------+------------------+------------------------------------------+ | mysql-bin.000003 | 800 | | | ceb0ca3d-8366-11e8-ad2b-000c298b7c9a:1-5 | +------------------+----------+--------------+------------------+------------------------------------------+ 1 row in set (0.00 sec)
slave上
mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | sys | | test01 | +--------------------+ 5 rows in set (0.07 sec) mysql> show slave status\G; *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 10.0.0.132 Master_User: rep Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000003 Read_Master_Log_Pos: 800 Relay_Log_File: slave-relay-bin.000005 Relay_Log_Pos: 1013 Relay_Master_Log_File: mysql-bin.000003 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: 800 Relay_Log_Space: 1473 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: ceb0ca3d-8366-11e8-ad2b-000c298b7c9a Master_Info_File: /usr/local/mysql/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: ceb0ca3d-8366-11e8-ad2b-000c298b7c9a:1-5 Executed_Gtid_Set: ceb0ca3d-8366-11e8-ad2b-000c298b7c9a:1-5 Auto_Position: 1 Replicate_Rewrite_DB: Channel_Name: Master_TLS_Version: 1 row in set (0.00 sec)
需要注意的是,GTID的值在完成一次事務(wù)后,變成了ceb0ca3d-8366-11e8-ad2b-000c298b7c9a:1-5(自增1)
6、排障
思路
a、確保master開放3306端口
b、最好關(guān)閉selinux
c、master上授權(quán)同步,slave上change master命令指定master的信息不要寫錯(cuò)
d、UUID問題
如果你出現(xiàn)了上圖所示的問題,表示你的master和slave的UUID是一樣的,一般這種情況多出現(xiàn)于克隆虛擬機(jī)
解決辦法:
找到slave上的MySQL數(shù)據(jù)目錄下的auto.cnf文件(這個(gè)文件其實(shí)是自動(dòng)生成的mysql服務(wù)器的UUID值),將它刪除,然后重啟MySQL,然后MySQL會(huì)重新生成一個(gè)UUID。然后停掉slave,重新開啟就可以了(我的mysql的數(shù)據(jù)目錄是在/usr/local/mysql/data下,詳情查看my.cnf配置文件)
cd /usr/local/mysql/data rm -f auto.cnf systemctl restart mysql
[root@slave data]# cat auto.cnf [auto] server-uuid=020c7f26-be57-11e8-8e2d-000c29b63bad
通過cat命令查看該文件,發(fā)現(xiàn)UUID已經(jīng)改變
mysql -uroot -p mysql> stop slave; mysql> start slave;
e、總結(jié)
排障過程中,注意需要停掉slave,做完修改之后在開啟,否則你的修改可能是不會(huì)生效的。