Mysql 主從資料庫同步(centos篇)

環境:主伺服器:centos 5.2 mysql 5.1.35 源碼 IP:192.168.1.22從伺服器:centos 5.2 mysql 5.1.35 源碼 IP:192.168.1.33配置:一、主伺服器 1.1、建立一個複製使用者，具有replication slave 許可權。mysql>grant replication slave on *.* to 'repl'@'192.168.1.22' identified by 'repl'; 1.2、編輯my.cnf檔案vi /etc/my.cnf
添加
server-id=1
並開啟log-bin二進位記錄檔
log-bin=mysql-bin注:需要把預設的server-id=1去掉 1.3、啟動mysql資料庫

mysqld_safe --user=mysql &

1.4、設定讀鎖

mysql>flush tables with read lock;

1.5、得到binlog記錄檔名和位移量mysql>show master status;+------------------+----------+--------------+------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.0000010 | 106| | |
+------------------+----------+--------------+------------------+ 1.6、備份要同步的資料庫

mysqldump test > test.sql

1.7、解鎖mysql>unlock tables; 二、從伺服器 2.1、編輯my.cnf檔案vi /etc/my.cnf
添加
server-id=2注:需要把預設的server-id=1去掉 2.2、啟動從資料庫

mysqld_safe --user=mysql &

2.3、對從資料庫進行相應設定mysql> change master to
-> master_host='192.168.1.22'
-> master_user='repl'
-> master_password='repl'
-> master_log_file='mysql-bin.0000010'
-> master_log_pos=106; 2.4、啟動從伺服器slave線程mysql>start slave;執行show processlist命令顯示以下進程:mysql>show processlist\G
*************************** 2. row ***************************
Id: 2
User: system user
Host:
db: NULL
Command: Connect
Time: 2579
State: Has read all relay log; waiting for the slave I/O thread to update it
Info: NULL

表示slave已經串連上master，開始接受並執行日誌 2.5、查看slave線程狀態mysql>show slave status;*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.1.22 Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.0000010
Read_Master_Log_Pos: 106
Relay_Log_File: centos-relay-bin.000002
Relay_Log_Pos: 529
Relay_Master_Log_File: mysql-bin.0000010
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: 106
Relay_Log_Space: 830
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:
1 row in set (0.00 sec) 驗證是否配置正確在從伺服器上執行show slave status\G;
Waiting for master to send event
Slave_IO_Running: Yes
Slave_SQL_Running: Yes如以上二行同時為Yes 說明配置成功 測試1、在主伺服器test資料庫中建立user表mysql>use test;
mysql>create table user(id int);2、在從伺服器中查看user表mysql>use test;
mysql> show tables like 'user';
+----------------------+
| Tables_in_test(user) |
+----------------------+
| user |
+----------------------+
1 row in set (0.00 sec)說明主從資料同步成功。 問題?1.在從資料庫中查看slave狀態時出現The slave I/O thread stops because master and slave have equal MySQL server ids; these ids must be different for replication to work (or the --replicate-same-server-id option must be used on slave but this does not always make sense; please check the manual before using it)說明方從伺服器裡my.cnf中的server-id有相同的。解決辦法:修改my.cnf裡的server-id，並重啟資料庫服務。my.cnf檔案預設有server-id=1 其它說明主伺服器my.cnf#binlog-do-db=需要備份的資料庫名，可寫多行
#binlog-ignore-db=不需要備份的資料庫名，可寫多行
從伺服器my.cnf# replicate-do-db=test 需要備份的資料庫名
# replicate-ignore-db=mysql 忽略的資料庫
# master-connect-retry=60 如果從伺服器發現主伺服器斷掉，重新串連的時間差(秒)以下設定也可直接修改my.cnf設定檔log-bin=mysql-bin
master-host=192.168.1.22master-user=replmaster-password=repl
master-port=3306

主從伺服器同步維護由於各種原因，導致主從資料不一致，在負載低的時候，進行手動同步.在主伺服器上執行 mysql>flush tables with read lock;Query OK,rows affected (0.01 sec)mysql>show master status;+------------------+----------+--------------+------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.0000011 | 260| | |
+------------------+----------+--------------+------------------+在從伺服器上執行先得到當前主伺服器的二進位檔案名和位移量,執行命令使從伺服器與主伺服器同步

mysql>select master_pos_wait('mysql-bin.0000011','260');
+--------------------------------------------------+
| master_pos_wait('mysql-bin.0000011','260') |
+--------------------------------------------------+
| 0 |
+--------------------------------------------------+
1 row in set (0.01 sec)

同步完成後，在主伺服器上執行解鎖mysql>unlock tables; 切換主從伺服器 當主伺服器出現故障時，可將從伺服器當主伺服器來使用.步驟如下:1、保證所有從資料庫都已經執行了relay log中的全部更新，在從伺服器中執行stop slave io_thread,用show processlist檢查，查看狀態是否是Has read all relay log,表示更新完成.mysql>stop slave io_thread;
Query OK,0 affected (0.00 sec)
mysql>show processlist\G; *************************** 2. row ***************************
Id: 2
User: system user
Host:
db: NULL
Command: Connect
Time: 4757
State: Has read all relay log; waiting for the slave I/O thread to update it
Info: NULL2、在從伺服器上執行stop slave，reset master命令，重設成主要資料庫mysql>stop slave;
Query OK,0 affected (0.00 sec)
mysql>reset master;
Query OK,0 affected (0.00 sec)

3、刪除新的主伺服器資料庫目錄中的master.info和relay-log.info檔案，否則下次重啟時還會按照從伺服器來啟動.