centos lvs+keepalived+mysql实现mysql数据库热备主主复制
一、环境：
linux：centos6.6虚拟ip(vip)：192.168.20.199
mysql master：192.168.20.193
mysql slave：192.168.20.195
（这里只是为了后文方便区分，一个叫master，一个叫slave，其实在主主复制中，都是master也都是slave，没有主从之分）
二、分别在两台服务器上安装同版本mysql
1、安装mysql
# yum -y install mysql-server mysql
# /etc/init.d/mysqld start #启动mysql 注意权限 非root使用sudo
# chkconfig mysqld on #设为开机启动
# cp /usr/share/mysql/my-medium.cnf /etc/my.cnf #拷贝配置文件（注意：如果/etc目录下面默认有一个my.cnf，直接覆盖即可）
2、为root账户设置密码
# mysql_secure_installation
回车，根据提示输入Y
输入2次密码，回车
根据提示一路输入Y
最后出现：Thanks for using MySQL!
mysql密码设置完成，重新启动 mysql：
# /etc/init.d/mysqld restart #重启
# mysql -V
mysql Ver 14.14 Distrib 5.1.73, for redhat-linux-gnu (x86_64) using readline 5.1
三、修改两台mysql配置文件
修改master的配置文件： vi /etc/my.cnf
#在[mysqld]添加如下内容#server-id = 193 #//只要主从不一样就行 我这里以ip地址后3位方便区分
log-bin = mysql-bin #开启二进制日志
binlog_format = MIXED #非必需
relay-log = mysqld-relay-bin #定义中继日志名，开启从服务器中继日志
#binlog-do-db=db_name #只复制db_name数据库
binlog-ignore-db = mysql #不复制mysql数据库
binlog-ignore-db = information_schema
binlog-ignore-db = performance_schema
replicate-wild-ignore-table = mysql.% #不复制mysql所有表
replicate-wild-ignore-table = information_schema.%
replicate-wild-ignore-table = performance_schema.%修改slave的配置文件： vi /etc/my.cnf#在[mysqld]添加如下内容#
server-id = 195
log-bin = mysql-bin
binlog_format = MIXED #非必需
relay-log = mysqld-relay-bin
binlog-ignore-db = mysql
binlog-ignore-db = information_schema
binlog-ignore-db = performance_schema
replicate-wild-ignore-table = mysql.%
replicate-wild-ignore-table = information_schema.%
replicate-wild-ignore-table = performance_schema.%四、手动同步数据库
如果master上已经有数据，那么执行主主互备之前，需要将master和slave上的两个mysql的数据保持同步，具体方法很多，可用工具Navicat for MySQL、phpmyadmin，也可直接命令行mysqldump、source；一般master备份前使用flush table with read lock;进行全局读锁，不能写；然后操作完后unlock tables;释放锁
master上执行
# mysqldump -uroot -p123456 --lock-all-tables --flush-logs hadoop > /data/hadoop.sqlmysql> create database hadoop default character set utf8 collate utf8_general_ci;
mysql> use hadoop
mysql> source /data/hadoop.sqlmaster执行：
mysql> grant REPLICATION SLAVE ON *.* TO test@'192.168.20.193' IDENTIFIED BY '123456';
mysql> flush privileges;mysql> grant REPLICATION SLAVE ON *.* TO test@'192.168.20.195' IDENTIFIED BY '123456';
mysql> flush privileges;六、启动互为主从的模式
在slave上执行下面命令，注意看Slave_IO_Running和Slave_SQL_Running，必须都是yes
mysql> show master status;
+------------------+----------+--------------+---------------------------------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+---------------------------------------------+
| mysql-bin.000001 | 334 | | mysql,information_schema,performance_schema |
+------------------+----------+--------------+---------------------------------------------+
1 row in set (0.00 sec)
mysql> change master to master_host='192.168.20.193', master_port=3306, master_user='test',master_password='123456', master_log_file='mysql-bin.000001',master_log_pos=334;
Query OK, 0 rows affected (0.06 sec)
mysql> start slave;
Query OK, 0 rows affected (0.00 sec)
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.20.193
Master_User: test
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 334
Relay_Log_File: mysqld-relay-bin.000002
Relay_Log_Pos: 251
Relay_Master_Log_File: mysql-bin.000001
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: mysql.%,information_schema.%,performance_schema.%
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 334
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)在master上执行下面命令，注意看Slave_IO_Running和Slave_SQL_Running，必须都是yes
mysql> show master status;
+------------------+----------+--------------+---------------------------------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+---------------------------------------------+
| mysql-bin.000001 | 334 | | mysql,information_schema,performance_schema |
+------------------+----------+--------------+---------------------------------------------+
1 row in set (0.00 sec)
mysql> change master to master_host='192.168.20.195', master_port=3306, master_user='test',master_password='123456', master_log_file='mysql-bin.000001',master_log_pos=334;
Query OK, 0 rows affected (0.10 sec)
mysql> start slave;
Query OK, 0 rows affected (0.00 sec)
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.20.195
Master_User: test
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 334
Relay_Log_File: mysqld-relay-bin.000002
Relay_Log_Pos: 251
Relay_Master_Log_File: mysql-bin.000001
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: mysql.%,information_schema.%,performance_schema.%
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 334
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)验证主主同步结果：
slave执行下面的sql语句
mysql> create database hadoop default character set utf8 collate utf8_general_ci;
Query OK, 1 row affected (0.00 sec)
mysql> use hadoop;
Database changed
mysql> create table user(id int(4) not null primary key auto_increment,name char (20) not null);
Query OK, 0 rows affected (0.06 sec)
mysql> insert into user values(null,1),(null,2),(null,3);
Query OK, 3 rows affected (0.00 sec)
Records: 3 Duplicates: 0 Warnings: 0
mysql> delete from user where id=2;
Query OK, 1 row affected (0.00 sec)
mysql> drop table user;
Query OK, 0 rows affected (0.00 sec)
mysql> create table user(id int(4) not null primary key auto_increment,name char (20) not null);
Query OK, 0 rows affected (0.07 sec)
mysql> insert into user values(null,1),(null,2),(null,3);
Query OK, 3 rows affected (0.00 sec)
Records: 3 Duplicates: 0 Warnings: 0
mysql> delete from user where id=2;
Query OK, 1 row affected (0.00 sec)
mysql> update user set name="在195机器修改" where id=1;
Query OK, 1 row affected, 1 warning (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 1
mysql> select * from user;
+----+----------------------+
| id | name |
+----+----------------------+
| 1 | 在195机器修改|
| 3 | 3 |
+----+----------------------+
2 rows in set (0.00 sec)
在master上查看
mysql> use hadoop;
Database changed
mysql> show tables;
Empty set (0.00 sec)
mysql> select * from user;
+----+----------------------+
| id | name |
+----+----------------------+
| 1 | 在195机器修改 |
| 3 | 3 |
+----+----------------------+
2 rows in set (0.00 sec)七、安装lvs+keepalived
cd /usr/src
yum install gcc make wget openssl-devel popt-devel libnl libnl-devel kernel-devel ipvsadm -y
ln -s /usr/src/kernels/2.6.32-642.3.1.el6.x86_64/ /usr/src/linux
wget http://www.keepalived.org/software/keepalived-1.2.7.tar.gz
tar zxvf keepalived-1.2.7.tar.gz
cd keepalived-1.2.7
./configure --with-kernel-dir=/usr/src/kernels/2.6.32-358.2.1.el6.x86_64/
make && make install
cp /usr/local/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/
cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/
mkdir /etc/keepalived
cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/
cp /usr/local/sbin/keepalived /usr/sbin/vi /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
notification_email {
[email protected]
}
notification_email_from [email protected]
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 60
priority 100
advert_int 1
nopreempt
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.20.199
}
}
virtual_server 192.168.20.199 3306 {
delay_loop 6
lb_algo rr
lb_kind DR
nat_mask 255.255.255.0
persistence_timeout 50
protocol TCP
real_server 192.168.20.193 3306 {
weight 1
notify_down /etc/keepalived/mysqlcheck/mysql.sh
TCP_CHECK {
connect_port 3306
connect_timeout 3
nb_get_retry 2
delay_before_retry 1
}
}
}
其中需要注意的是：
state BACKUP #master和slave均配置为BACKUP状态
nopreempt #为不强占模式，slave(slave)不用设置
notify_down #定义监测realserver失败下一步的动作
priority #slave要比master低
创建notify_down的脚本（master和slave都需创建，也可在master创建好，使用scp命令复制到slave，如scp -r mysqlcheck [email protected]:/etc/keepalived/ ）
mkdir -p /etc/keepalived/mysqlcheck/
cd /etc/keepalived/mysqlcheck/
vi mysql.sh
#!/bin/bash
pkill keepalived
chmod u+x mysql.sh其实就是杀掉keepalived进程，释放vip
slave的配置文件：
! Configuration File for keepalived
global_defs {
notification_email {
[email protected]
}
notification_email_from [email protected]
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 60
priority 90
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.20.199
}
}
virtual_server 192.168.20.199 3306 {
delay_loop 6
lb_algo rr
lb_kind DR
nat_mask 255.255.255.0
persistence_timeout 50
protocol TCP
real_server 192.168.20.195 3306 {
weight 1
notify_down /etc/keepalived/mysqlcheck/mysql.sh
TCP_CHECK {
connect_port 3306
connect_timeout 3
nb_get_retry 2
delay_before_retry 1
}
}
}
master和slave的keepalived都配置好了，分别将keepalived设置为开机启动并启动服务：
chkconfig keepalived on
service keepalived start
#查看进程
[root@localhost ~]# ps aux | grep keepalived
root 4696 0.0 0.2 110756 1440 ? Ss 16:12 0:00 /usr/sbin/keepalived -D
root 4698 0.0 0.6 112992 3036 ? S 16:12 0:00 /usr/sbin/keepalived -D
root 4699 0.0 0.4 112860 2252 ? S 16:12 0:00 /usr/sbin/keepalived -D
root 5236 0.0 0.1 103252 864 pts/1 S+ 17:04 0:00 grep keepalived然后
输入ip a命令能看到虚拟ip：192.168.20.199
输入ipvsadm -ln命令在虚拟服务器列表看到自己的ip就是成功的
九、测试(我是在本机window测试)
首先为方便测试在master和slave都开个远程连接帐号open，密码123456
mysql> grant all privileges on *.* to 'open'@'%' identified by '123456';
mysql> flush privileges;1、本机测试主从同步，通过VIP连接：
进入到mysql的bin目录，使用上面新建的远程帐号远程连接到虚拟ip，然后通过show variables like 'server_id';查看当前使用的是哪台mysql
2、测试keepalived实现mysql故障转移：
可以在master执行，/etc/init.d/mysqld stop，远程一直执行，show vaiables like 'server_id';发现会卡1~3s，server_id变为195，即master变为slave。即使重启master，vip也不会转移，因为采用的是不抢占模式，直到slave的服务挂，才会转移vip
左边是模拟mysql挂掉，右边是本机远程连接vip状况
