mysql主从同步，数据库双机热备份
mysql主从同步：
主服务器：
master：192.168.1.200
从服务器：
slave：192.168.1.225
一、master端配置：
vi /etc/my.cnf
server-id = 1 master端ID号
log-bin=/data/logbin/mysql-bin 日志路径及文件名
#binlog-do-db = cacti 同步cacti，此处关闭的话，就是除不允许的，其它的库均同步。
binlog-ignore-db = mysql 不同步mysql库，以下同上
binlog-ignore-db = test
binlog-ignore-db = information_schema
[root@localhost ~]# mysql -u root -p
mysql> grant replication slave on *.* to backdata@'192.168.1.225' identified by "backpass";
Query OK, 0 rows affected (0.03 sec)
（添加同步用的账号backdata 密码backpass，从服务器要用到）
mysql> flush privileges;
Query OK, 0 rows affected (0.02 sec)
mysql> flush tables with read lock;
Query OK, 0 rows affected (0.01 sec)
mysql> show master status;
+------------------+----------+--------------+------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000009 | 120366 | | |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)
（这里要记录下File和Position的值，在从服务器中要用到）
mysql> unlock tables;
(下面这一步是要在备份服务器上建立这个数据库，如果备份服务器上没有会出错，至于错误下面会有介绍)
#cd /var/lib/mysql
#tar -zcvf cacti.tgz
[root@localhost mysql]# scp cacti.tgz [email protected]:/var/lib/mysql/cacti.tgz
二、slave端配置：
[root@localhost ~]#vi /etc/my.cnf
server-id=2 #添加这一句
[root@localhost ~]# mysql -u root -p
mysql> slave stop;
Query OK, 0 rows affected, 1 warning (0.00 sec)
mysql> change master to
-> master_host='192.168.1.200',
-> master_user='backdata',
-> master_password='backpass',
-> master_log_file='mysql-bin.000009',
-> master_log_pos=120366;
Query OK, 0 rows affected (0.25 sec)
（这里面填的值就是在主服务器上刚才设置 记录的值）
mysql> start slave;
ERROR 1200 (HY000): The server is not configured as slave; fix in config file or with CHANGE MASTER TO
[root@localhost ~]#service mysqld restart
mysql> slave start;
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 4
Current database: *** NONE ***
Query OK, 0 rows affected (0.00 sec)
重启数据库后没有了上面的错误提示
mysql> show slave status \G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.1.200
Master_User: backdata
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000009
Read_Master_Log_Pos: 155726
Relay_Log_File: mysqld-relay-bin.000003
Relay_Log_Pos: 251
Relay_Master_Log_File: mysql-bin.000009
Slave_IO_Running: Yes
Slave_SQL_Running: No
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 1146
Last_Error: Error 'Table 'cacti.settings' doesn't exist' on query. Default database: 'cacti'. Query: 'REPLACE
INTO settings (name,value) VALUES ('poller_lastrun',1375515901)'
Skip_Counter: 0
Exec_Master_Log_Pos: 120366
Relay_Log_Space: 35767
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: NULL
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 1146
Last_SQL_Error: Error 'Table 'cacti.settings' doesn't exist' on query. Default database: 'cacti'. Query: 'REPLACE
INTO settings (name,value) VALUES ('poller_lastrun',1375515901)'
1 row in set (0.00 sec)
查看上面的Slave_IO_Running: Yes 和Slave_SQL_Running: Yes 2个都为yes则证明主从同步正常，如果有任一个显示NO,则证明同步有问题。
看错误提示是没有cacti这个数据库，在master复制过来数据库，上面已有介绍
[root@localhost mysql]# scp cacti.tgz [email protected]:/var/lib/mysql/cacti.tgz
[root@localhost mysql]#tar -zxvf cacti.tgz
[root@localhost mysql]#service mysqld restart
mysql> show slave status \G
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 4
Current database: *** NONE ***
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.1.200
Master_User: backdata
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000009
Read_Master_Log_Pos: 169963
Relay_Log_File: mysqld-relay-bin.000005
Relay_Log_Pos: 251
Relay_Master_Log_File: mysql-bin.000009
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: 169963
Relay_Log_Space: 407
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)
正常了
以上是安装过程，同步的情况将继续测试。