mysql数据库同步

mysql数据库同步

 1.1. Master 设置步骤

1. 配置 my.cnf 文件

   确保主服务器主机上my.cnf文件的[mysqld]部分包括一个log-bin选项。该部分还应有一个server-id=Master_id选项

   # vim /etc/mysql/my.cnf
   
   server-id               = 1
   log_bin                 = /var/log/mysql/mysql-bin.log
   expire_logs_days        = 10
   max_binlog_size         = 100M
   binlog_do_db            = test
   binlog_ignore_db        = mysql
   					

   bind-address默认是127.0.0.1你必须更改它，否则Slave将无法链接到 Master

   #bind-address		= 127.0.0.1
   bind-address		= 0.0.0.0
   					

   重启服务器

   neo@netkiller :~$ sudo /etc/init.d/mysql reload
    * Reloading MySQL database server mysqld          [ OK ]
   					

   建议使用reload,如果不起作用再用restart

2. 登录slave服务器，测试主库3306工作情况，如果看到下面相关信息表示工作正常。

   					
   # telnet 192.168.1.246 3306
   Trying 192.168.1.246...
   Connected to 192.168.1.246.
   Escape character is '^]'.
   I
   5.1.61-0ubuntu0.11.10.1-log1W<gs/*'#}p<u[J=5//:
   					
   					

3. 创建账户并授予REPLICATION SLAVE权限

   					
   mysql> GRANT REPLICATION SLAVE ON *.* TO 'replication'@'%.mydomain.com' IDENTIFIED BY 'slavepass';
   mysql> FLUSH PRIVILEGES;
   					
   					

   GRANT REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO replication@'192.168.245.131' IDENTIFIED BY 'slavepass'

4. 锁表禁止写入新数据

   					
   mysql> FLUSH TABLES WITH READ LOCK;
   					
   					

5. 查看Master 工作状态

   					
   mysql> SHOW MASTER STATUS;
   +------------------+----------+--------------+------------------+
   | File             | Position | Binlog_Do_DB | Binlog_Ignore_DB |
   +------------------+----------+--------------+------------------+
   | mysql-bin.000002 |      106 | test         | mysql            |
   +------------------+----------+--------------+------------------+
   1 row in set (0.00 sec)
   					
   					

   如果显示下面内容表示，配置不正确

   					
   
   mysql> SHOW MASTER STATUS;
   Empty set (0.02 sec)
   					
   					

   取得快照并记录日志名和偏移量后，可以在主服务器上重新启用写活动

   					
   mysql> UNLOCK TABLES;
   					
   					

5.1.2. Slave

过程 1.2. Slave 设置步骤

1. 配置my.cnf

   从服务器的ID必须与主服务器的ID不相同,如果设置多个从服务器，每个从服务器必须有一个唯一的server-id值，必须与主服务器的以及其它从服务器的不相同。

   # vim /etc/mysql/my.cnf
   
   [mysqld]
   server-id               = 2
   					

2. # service mysql restart
   mysql start/running, process 22893
   					

3. 指定 master 相关参数

   在从服务器上执行下面的语句，用你的系统的实际值替换选项值

   					
   mysql> CHANGE MASTER TO
   	->     MASTER_HOST='master_host_name',
   	->     MASTER_USER='replication_user_name',
       ->     MASTER_PASSWORD='replication_password',
       ->     MASTER_LOG_FILE='recorded_log_file_name',
       ->     MASTER_LOG_POS=recorded_log_position;
   	   				
   					

   CHANGE MASTER TO MASTER_HOST='192.168.245.129', MASTER_USER='replication', MASTER_PASSWORD='slavepass';

   					
   mysql> CHANGE MASTER TO MASTER_HOST='192.168.245.129', MASTER_USER='repl', MASTER_PASSWORD='slavepass';
   Query OK, 0 rows affected (0.14 sec)
   					
   					

4. 启动从服务器线程

   					
   mysql> START SLAVE;
   Query OK, 0 rows affected (0.00 sec)
   					
   					

5. SLAVE STATUS

   					
   mysql> SHOW SLAVE STATUS\G
   *************************** 1. row ***************************
                Slave_IO_State: Connecting to master
                   Master_Host: 192.168.245.129
                   Master_User: repl
                   Master_Port: 3306
                 Connect_Retry: 60
               Master_Log_File:
           Read_Master_Log_Pos: 4
                Relay_Log_File: mysqld-relay-bin.000002
                 Relay_Log_Pos: 98
         Relay_Master_Log_File:
              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: 0
               Relay_Log_Space: 98
               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
   1 row in set (0.00 sec)
   					
   					

5.1.3. Testing

1. 登录 master

   复制进程的信息

   SHOW PROCESSLIST语句可以提供在主服务器上和从服务器上发生的关于复制的信息

   mysql> SHOW PROCESSLIST\G
   *************************** 1. row ***************************
        Id: 62
      User: replication
      Host: ken-hx409.local:36465
        db: NULL
   Command: Binlog Dump
      Time: 679
     State: Has sent all binlog to slave; waiting for binlog to be updated
      Info: NULL
   *************************** 2. row ***************************
        Id: 64
      User: root
      Host: localhost
        db: NULL
   Command: Query
      Time: 0
     State: NULL
      Info: SHOW PROCESSLIST
   2 rows in set (0.00 sec)
   
   					

2. 登录从库，查看复制线程

   					
   mysql> SHOW PROCESSLIST\G
   *************************** 1. row ***************************
        Id: 273
      User: root
      Host: localhost
        db: NULL
   Command: Query
      Time: 0
     State: NULL
      Info: SHOW PROCESSLIST
   *************************** 2. row ***************************
        Id: 276
      User: system user
      Host:
        db: NULL
   Command: Connect
      Time: 2
     State: Waiting for master to send event
      Info: NULL
   *************************** 3. row ***************************
        Id: 277
      User: system user
      Host:
        db: NULL
   Command: Connect
      Time: 2
     State: Has read all relay log; waiting for the slave I/O thread to update it
      Info: NULL
   3 rows in set (0.00 sec)
   					
   					

   如果没有复制进程，请使用start slave;启动

   					
   mysql> SHOW PROCESSLIST\G
   *************************** 1. row ***************************
        Id: 273
      User: root
      Host: localhost
        db: NULL
   Command: Query
      Time: 0
     State: NULL
      Info: SHOW PROCESSLIST
   1 row in set (0.02 sec)
   
   mysql> start slave;
   Query OK, 0 rows affected (0.00 sec)
   					
   					

3. 登录 master

   					
   mysql> insert into foo(id,data) values(2,'Hello world!!!');
   Query OK, 1 row affected (0.00 sec)
   					
   					

4. 登录 slave

   					
   mysql> select * from foo;
   					
   					

   在master服务器上插入一条记录，你可以立刻在slave服务器上看到变化。

5.1.4. 将现有数据库迁移到主从结构数据库

数据库已经存在的情况下怎么迁移

1. Master 锁表禁止写入新数据

   					
   mysql> FLUSH TABLES WITH READ LOCK;
   					
   					

2. Slave 停止复制进程

   					
   mysql> stop slave;
   					
   					

3. 备份Master数据库

   					
   mysqldump yourdb | gzip > yourdb.sql.gz
   					
   					

4. 恢复数据库

   如果使用mysqldump备份主服务器的数据，将转储文件装载到从服务器

   					
   # zcat yourdb.sql.gz | mysql -u root -p yourdb
   					
   					

5. 启动 Slave 复制进程

   					
   mysql> start slave;
   					
   					

6. 解除 Master 表锁定

   					
   mysql> UNLOCK TABLES;
   					
   					

MyIASM引擎可以采用下面方法

备份数据库

# tar zcvf mysql-snapshot.tar.gz /var/lib/mysql/neo
			

复制给从数据库

scp mysql-snapshot.tar.gz  [email protected]:/tmp
			

snapshot 恢复

$ tar zxvf mysql-snapshot.tar.gz
$ cd /var/lib/mysql

$ mv /tmp/var/lib/mysql/neo .
$ sudo chown mysql.mysql -R neo
			

重新启动Mysql

$ sudo /etc/init.d/mysql restart
			

有兴趣可以看看mysqlhotcopy

5.1.5. 主从复制安全问题

复制帐号权限

grant replication slave on *.* to 'replication'@'192.168.1.%' identified by '000000';
			

主库数据库操作帐号权限

grant DELETE, INSERT, SELECT, UPDATE ON your_user.* to yourdb@'your_host' identified by 'password' with grant option;
			

从库数据库操作帐号权限

grant SELECT ON your_user.* to yourdb@'your_host' identified by 'password' with grant option;
			

从库必须收回写操作

5.1.6. 主从不同步问题

执行下面语句

stop slave;
set global sql_slave_skip_counter =1 ;
start slave;
			

Seconds_Behind_Master 值从NULL变为大于等于0是表示已经同步

Seconds_Behind_Master: NULL
Seconds_Behind_Master: 8893
			

5.2. Master Master(主主)

5.2.1. Master A

my.cnf 文件加入下面的内容

cp /etc/mysql/my.cnf /etc/mysql/my.cnf.old
vim /etc/mysql/my.cnf

[mysqld]
server-id = 1
log-bin=/data/mysql/binlog/binlog
binlog-do-db = test
binlog-ignore-db=mysql

log-slave-updates
sync_binlog=1
auto_increment_offset=1
auto_increment_increment=2
replicate-do-db = test
replicate-ignore-db = mysql,information_schema
			

创建复制权限

grant replication slave on *.* to 'replication'@'192.168.1.%' identified by '000000';
flush privileges;
			

			
mysql>flush tables with read lock;

mysql> show master status\G
*************************** 1. row ***************************
File: binlog.000007
Position: 107
Binlog_Do_DB: test
Binlog_Ignore_DB: mysql
1 row in set (0.00 sec)
			
			

5.2.2. Master B

创建复制权限

grant replication slave on *.* to 'replication'@'192.168.1.%' identified by '000000';
flush privileges;
			

my.cnf 文件加入下面的内容

[mysqld]
server-id = 2
log-bin = /data/mysql/binlog/binlog
replicate-do-db = test
replicate-ignore-db = mysql,information_schema

binlog-do-db = test
binlog-ignore-db=mysql
log-slave-updates
sync_binlog=1
auto_increment_offset=2
auto_increment_increment=2
			

B 与 A 配置文件不同的两处。

server-id = 2
auto_increment_offset=2
			

			
mysql> show master status\G
*************************** 1. row ***************************
File: binlog.000005
Position: 107
Binlog_Do_DB: test
Binlog_Ignore_DB: mysql
1 row in set (0.00 sec)
			
			

5.2.3. 将Master A 数据库 同步到 Master B 两端数据库内容保持一致

Master A，首先锁表为只读状态

			
mysqldump --databases test > /tmp/test.sql
			
			

Master B 创建一个与Master A同名的空数据库,然后将备份文件恢复到数据库中

			
# mysql
mysql> CREATE DATABASE test;
mysql>\q

# scp 192.168.1.1:/tmp/test.sql ./
# mysql -uroot -p test < /tmp/test.sql
  			
			

5.2.4. Master A - B 同步两端数据库

master-A

			
mysql>change master to master_host='192.168.1.2', master_user='replication', master_password='000000', master_log_file='binlog.000005', master_log_pos=107;
			
			

master-B

			
mysql>change master to master_host='192.168.1.1', master_user='replication', master_password='000000', master_log_file='binlog.000007', master_log_pos=107;
			
			

5.2.5. Master A 数据库解除只读权限

Master A 解锁

			
mysql> UNLOCK TABLES;
			
			

5.2.6. 查看主主的工作状态

分别在Master A与B 上运行

			
mysql>show slave status\G;

Slave_IO_Running: Yes
Slave_SQL_Running: Yes
			
			

5.3. 与复制有关的问题

5.3.1. expire-logs-days

缺省expire-logs-days为30天。这里设为7天，可根据自己情况调整。

[mysqld]
expire-logs-days = 7
			

5.3.2. Semisynchronous Replication

			
mysql> SHOW VARIABLES LIKE "have_dynamic_loading";
+----------------------+-------+
| Variable_name        | Value |
+----------------------+-------+
| have_dynamic_loading | YES   |
+----------------------+-------+
1 row in set (0.00 sec)

mysql>
			
			

master  > INSTALL PLUGIN rpl_semi_sync_master SONAME ‘libsemisync_master.so’;
slave-x > INSTALL PLUGIN rpl_semi_sync_slave SONAME ‘libsemisync_slave.so’;
master  > SET GLOBAL rpl_semi_sync_master_enabled=1;
slave-x > SET GLOBAL rpl_semi_sync_slave_enabled=1;
			

CREATE USER 'replication'@'192.168.1.%' IDENTIFIED BY 'password';
GRANT ALL PRIVILEGES ON *.* TO 'replication'@'192.168.1.%' IDENTIFIED BY 'password' WITH GRANT OPTION MAX_QUERIES_PER_HOUR 0 MAX_CONNECTIONS_PER_HOUR 0 MAX_UPDATES_PER_HOUR 0 MAX_USER_CONNECTIONS 0 ;
			

master_heartbeat_period

STOP SLAVE;
CHANGE MASTER TO master_heartbeat_period= milliseconds;
START SLAVE;
			

mysql> CHANGE MASTER TO MASTER_HOST='xxx.xxx.xxx.xxx', MASTER_USER='root', MASTER_PASSWORD='password', MASTER_PORT=3306, MASTER_CONNECT_RETRY=10, MASTER_LOG_FILE='mysql-bin.000004', MASTER_LOG_POS=107;
			

跳过出问题的MySQL实例

CHANGE MASTER TO MASTER_HOST=xxx.xxx.xxx.xxx IGNORE_SERVER_IDS=y
			

编辑my.cnf加入

# On Master
[mysqld]
rpl_semi_sync_master_enabled=1
rpl_semi_sync_master_timeout=1000 # 1 second

# On Slave
[mysqld]
rpl_semi_sync_slave_enabled=1