規劃
master 192.168.56.2
slave 192.168.56.5
1、在主庫上，設置一個復制使用的賬戶rep1，並授予REPLICATION SLAVE權限。
mysql> grant replication slave on *.* to 'rep1'@'192.168.56.2' identified by '123456'; Query OK, 0 rows affected (0.01 sec)
2、修改主數據庫服務器的配置文件my.cnf，開啟BINLOG,並設置server-id的值。這兩個參數的修改需要重新啟動數據庫服務才可以生效。
vi /etc/my.cnf
[mysqld]
log-bin=/home/mysql/log/mysql-bin.log
server-id=1
[root@rhel6 ~]# service mysql restart Shutting down MySQL.. [ OK ] Starting MySQL. [ OK ]
3、在主庫上，設置讀鎖定有效，這個操作是為了確保沒有數據庫操作，以便獲得一個一致性的快照。
mysql> flush tables with read lock; Query OK, 0 rows affected (0.02 sec)
4、得到主庫上當前的二進制日志名和偏移量值。這個操作的目的是為了從數據庫啟動以後，從這個點開始進行數據的恢復。
mysql> show master status; +-----------------+----------+--------------+------------------+-------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set | +-----------------+----------+--------------+------------------+-------------------+ | mysqlbin.000021 | 120 | | | | +-----------------+----------+--------------+------------------+-------------------+ 1 row in set (0.03 sec)
5、現在主數據庫服務器已經停止了更新操作，需要生成主數據庫的備份，備份的方式有很多種，可以直接在操作系統下復制全部的數據文件到從數據庫服務器上，也可以通過mysqldump導出數據或者使用ibbackup工具進行數據庫的備份。如果主數據庫的服務可以停止，那麼直接復制數據文件應該是最快的生成快照的方法：
[root@rhel6 lib]# tar -zcvf mysql.tar.gz mysql mysql/ tar: mysql/mysql.sock: socket ignored mysql/mysqlbin.000019 mysql/test1/ mysql/test1/db.opt mysql/test1/pack.MYD mysql/test1/myisam2.frm mysql/test1/emp.ibd mysql/test1/mer_myisam.MRG mysql/test1/emp.frm mysql/test1/pri_t.TRG .... 傳到從數據庫 [root@rhel6 lib]# scp mysql.tar.gz [email protected]:/root [email protected]'s password: mysql.tar.gz 100% 1402KB 1.4MB/s 00:00
6、主數據庫備份完畢後可恢復寫操作，剩下的只需要在從庫上執行
mysql> unlock tables; Query OK, 0 rows affected (0.02 sec)
7、將主數據庫的一致性備份恢復到從數據庫上。如果是使用.tar.gz打包的文件包，只需要解開到相應的目錄即可。
tar -zxvf mysql.tar.gz
8、修改從數據庫的配置文件my.cnf，增加server-id參數。注意server-id的值必須是唯一的，不能和主數據庫的配置相同，如果有多個從數據庫服務器，每個從數據庫服務器必須有自己唯一的server-id值。
vi my.cnf
[mysqld]
server-id=2
9、在從庫上，使用--skip-slave-start選項啟動數據庫，這樣不會立即啟動從數據庫服務上的復制進程，方便我們對從數據庫的服務進行進一步的配置(可選)
mysqld_safe --skip-slave-start &
或者修改my.cnf,添加skip-slave-start參數，service mysql start
10、對從數據庫服務器做相應設置，指定復制使用的用戶，主數據庫服務器的IP、端口以及開始執行復制的日志文件和位置等
mysql> change master to -> master_host='192.168.56.2', -> master_user='rep1', -> master_port=3306, -> master_password='123456', -> master_log_file='mysqlbin.000021', -> master_log_pos=120; Query OK, 0 rows affected, 2 warnings (0.08 sec)
11、在從庫上，啟動slave線程
mysql> start slave; Query OK, 0 rows affected (0.17 sec)
12、從庫上查看進程
mysql> show processlist \G; *************************** 1. row *************************** Id: 1 User: root Host: localhost db: zx Command: Query Time: 0 State: init Info: show processlist *************************** 2. row *************************** Id: 4 User: system user Host: db: NULL Command: Connect Time: 1484 State: Waiting for master to send event Info: NULL *************************** 3. row *************************** Id: 5 User: system user Host: db: NULL Command: Connect Time: 739 State: Slave has read all relay log; waiting for the slave I/O thread to update it Info: NULL 3 rows in set (0.00 sec) mysql> show slave status \G *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 192.168.56.2 Master_User: rep1 Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysqlbin.000021 Read_Master_Log_Pos: 652 Relay_Log_File: rhel6-relay-bin.000002 Relay_Log_Pos: 814 Relay_Master_Log_File: mysqlbin.000021 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: 652 Relay_Log_Space: 987 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: 3743271b-aa6d-11e6-aa2e-080027e5f5dd Master_Info_File: /mysqldata/master.info SQL_Delay: 0 SQL_Remaining_Delay: NULL Slave_SQL_Running_State: Slave has read all relay log; waiting for the slave I/O thread to update it Master_Retry_Count: 86400 Master_Bind: Last_IO_Error_Timestamp: Last_SQL_Error_Timestamp: Master_SSL_Crl: Master_SSL_Crlpath: Retrieved_Gtid_Set: Executed_Gtid_Set: Auto_Position: 0 1 row in set (0.00 sec)
Slave_IO_Running和Slave_SQL_Running全部為YES才算搭建成功。如果出錯查看報錯原因。我搭建時遇到的兩個錯誤：
(1)Last_IO_Error: Fatal error: The slave I/O thread stops because master and slave have equal MySQL server UUIDs; these UUIDs must be different for replication to work.
原因：搭建時把主庫整個目錄復制過來的，主庫和從庫的UUID一致了，修改從庫的UUID即可。
方法：修改$datadir/auto.cnf，按照16進制格式隨便改一下，重啟mysql即可。
(2)Last_IO_Error: Got fatal error 1236 from master when reading data from binary log: 'Could not find first log file name in binary log index file'
原因：配置change master to時把master_log_file配置錯誤
方法：change master to master_log_file='mysqlbin.000021';start slave;即可。
13、測試復制的正確性
主庫 mysql> create database zx; Query OK, 1 row affected (0.05 sec) mysql> use zx; Database changed mysql> create table t(id int); Query OK, 0 rows affected (0.09 sec) mysql> insert into t values(1),(2),(3); Query OK, 3 rows affected (0.01 sec) Records: 3 Duplicates: 0 Warnings: 0 從庫 mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | data | | mysql | | performance_schema | | test | | test1 | | zx | +--------------------+ 7 rows in set (0.00 sec) mysql> use zx Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A Database changed mysql> select * from t; +------+ | id | +------+ | 1 | | 2 | | 3 | +------+ 3 rows in set (0.00 sec)
