mysql数据库同步

mysql数据库同步

1.1. Master 设置步骤

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

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//:

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'
锁表禁止写入新数据
```
mysql> FLUSH TABLES WITH READ LOCK;
```

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

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
					
```

# service mysql restart

mysql start/running, process 22893

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)

启动从服务器线程

mysql> START SLAVE;

Query OK, 0 rows affected (0.00 sec)

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

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)

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)

mysql> insert into foo(id,data) values(2,'Hello world!!!');

Query OK, 1 row affected (0.00 sec)

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

Master 锁表禁止写入新数据
```
mysql> FLUSH TABLES WITH READ LOCK;
```
Slave 停止复制进程
```
mysql> stop slave;
```

备份Master数据库

mysqldump yourdb | gzip > yourdb.sql.gz

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
```
启动 Slave 复制进程
```
mysql> start slave;
```
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  neo@192.168.245.131:/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