MYSQL Replication 主从配置
MySQL Replication 又叫做AB复制或者主从复制。它主要用于MySQL的实时备份或者读写分离。在配置之前先做一下准备工作，配置两台mysql服务器，或者在一台服务器上配置两个端口也可以。本文创建了两个虚拟机各安装了一个mysql用于主从配置，文章结尾处也有同一台服务器配置两个不同端口mysql方法，可供参考。
一、主服务称master，从服务器称slave
[root@localhost 主服务器]# hostname master
[root@localhost 从服务器]# hostname slave
二、配置master
1. 配置文件
[root@localhost mysql]# vi /etc/my.cnf
#主数据库端ID号
server_id = 1
#开启二进制日志
log-bin = mysql-bin
#需要复制的数据库名，如果复制多个数据库，重复设置这个选项即可
binlog-do-db = db
2. 重启服务，如果启动失败，杀死进程试试
[root@localhost ~]# killall mysqld
[root@localhost ~]# /etc/init.d/mysqld restart
Starting MySQL.. SUCCESS!
3.配置slave访问master的用户的ip权限
[root@localhost ~]# mysql -uroot -p
Enter password:
mysql> grant replication slave on *.* to 'slave'@'192.168.159.131' identified by '123456';
//ip填写从服务器ip，slave是创建的mysql用户名
Query OK, 0 rows affected (0.00 sec)
//现在slave可以连接master数据库了
mysql> flush tables with read lock;
//锁定数据库，此时不允许更改任何数据
mysql> show master status;
//查看状态，这些数据是要记录的，一会要在slave端用到
+------------------+----------+--------------+------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000030 | 730 | | |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)
三、配置slave
1.配置文件
[root@localhost mysql]# vi /etc/my.cnf
server-id = 2
#log-bin=mysql-bin
找到 “server-id = 1” 这一行，删除掉或者改为 “server-id = 2” 总之不能让这个id和master一样，否则会报错。另外在 从上，你也可以选择性的增加如下两行，对应于主上增加的两行:
replicate-do-db=databasename1,databasename2
replicate-ignore-db=databasename1,databasename2
2.重启服务，如果启动失败，杀死进程试试
[root@localhost ~]# killall mysqld
[root@localhost ~]# /etc/init.d/mysqld restart
Starting MySQL.. SUCCESS!
3. slave连接master数据库测试
[root@localhost mysql]# mysql -uslave -p123456 -h192.168.159.132
Welcome to the MySQL monitor. Commands end with ; or \g.
mysql>
四、主从关联配置
1．master配置关联
[root@localhost ~]# mysqldump -uroot -p123456 java_test > 1.sql
//将master数据库拷贝到1.sql
[root@localhost ~]# scp 1.sql [email protected]:/root/
//将1.sql拷贝到slave上
2. slave配置关联
[root@localhost ~]# mysql -uroot -p123456
mysql> slave stop;
//先把从的服务停掉
mysql>change master to master_host='192.168.159.132', ->master_port=3306,
-> master_user='slave', master_password='123456',
-> master_log_file='mysql-bin.000030',master_log_pos=730;
//配置关联master，3306可以默认不写，master_log_file参考之前记录的信息
mysql> slave start;
Query OK, 0 rows affected (0.00 sec)
4.master解锁数据库以便从库查询
[root@localhost /]# mysql -uroot -p123456
mysql> unlock tables;
5.然后查看slave的状态
mysql> show slave status\G;
确认以下两项参数都为yes:
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
6.如果报错参考
发生错误：ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version
解决方案有两个:
一、mysql> grant replication slave on *.* to 'slave'@'192。168.159.131' identified by '123456';时候语句有误导致权限不够,重新创建重复之后操作
二、删除mysql数据存放目录的多余*bin*文件
[root@localhost data]#rm -rf /var/mysql/data/*bin*
123.sql mysql-bin.000001 mysql-bin.000012 mysql-bin.000023
haha/ mysql-bin.000002 mysql-bin.000013 mysql-bin.000024
ibdata1 mysql-bin.000004 mysql-bin.000015 mysql-bin.000026
五、测试主从效果
master端创建haha数据库
slave端查询可显示则说明数据同步
附加：一台服务器配置两个mysql方法
1.配lnmp环境时已经装好一个mysql，直接复制
[root@localhost ~]# cd /usr/local/
[root@localhost local]# cp -r mysql mysql_2
[root@localhost local]# cd mysql_2
[root@localhost mysql_2]# ./scripts/mysql_install_db --user=mysql --datadir=/var/mysql2/data
2.初始化mysql
[mysql@localhost ~]$ cd /usr/local/mysql
[mysql@localhost mysql]$ scripts/mysql_install_db
3.复制配置文件
[root@localhost mysql_2]# cp /etc/my.cnf ./my.cnf
[root@localhost mysql_2]# vim my.cnf
修改
port = 3307
datadir = /var/mysql2/data
socket = /usr/local/mysql_2/mysql.sock
4.复制启动脚本
[root@localhost mysql_2]# cp support-files/mysql.server /etc/init.d/mysqld2
修改
basedir=/usr/local/mysql_2
datadir=/var/mysql2/data
$bindir/mysqld_safe --defaults-file=$basedir/my.cnf --datadir="$datadir" --pid-file="$mysqld_pid_file_path" $other_args >/dev/null 2>&1 &
5.启动两个mysql并检测
[root@localhost mysql]# /etc/init.d/mysqld restart
Shutting down MySQL. SUCCESS!
Starting MySQL.. SUCCESS!
[root@localhost mysql]# /etc/init.d/mysqld2 restart
Shutting down MySQL. SUCCESS!
Starting MySQL.. SUCCESS!
[root@localhost mysql]# netstat -lnp | grep mysql
tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 4038/mysqld
tcp 0 0 0.0.0.0:3307 0.0.0.0:* LISTEN 4392/mysqld
unix 2 [ ACC ] STREAM LISTENING 12888 4392/mysqld /usr/local/mysql_2/mysql.sock
unix 2 [ ACC ] STREAM LISTENING 12645 4038/mysqld /usr/local/mysql/mysql.sock
如果报错Starting MySQL.. ERROR! The server quit without updating PID file (/var/mysql/data/localhost.localdomain.pid).请尝试初始化./scripts/mysql_install_db --user=mysql --datadir=/var/mysql2/data
