mysql高可用-双主热备Keepalived+Mysql

1、配置两台Mysql主主同步

[root@master ~]# yum install mysql-server mysql -y
[root@master ~]# service mysqld start
[root@master ~]# mysqladmin -u root password 123.com
[root@master ~]# vi /etc/my.cnf                   #开启二进制日志，设置id
[mysqld]
server-id = 1                    #backup这台设置2
log-bin = mysql-bin
binlog-ignore-db = mysql,information_schema     #忽略写入binlog日志的库
auto-increment-increment = 2             #字段变化增量值
auto-increment-offset = 1               #初始字段ID为1
slave-skip-errors = all                #忽略所有复制产生的错误     
[root@master ~]# service mysqld restart

　　# mysql -uroot -p'密码'

先查看下log bin日志和pos值位置

master配置如下：

[root@ master ~]# mysql -u root -p123.com
mysql> GRANT  REPLICATION SLAVE ON *.* TO 'replication'@'192.168.0.%' IDENTIFIED  BY 'replication';
mysql> flush  privileges;
mysql> change  master to
    ->  master_host='192.168.0.203',
    ->  master_user='replication',
    ->  master_password='replication',
    ->  master_log_file='mysql-bin.000002',
    ->  master_log_pos=106;  #对端状态显示的值
mysql> start  slave;         #启动同步

　　backup配置如下：

[root@backup ~]#  mysql -u root -p123.com
mysql> GRANT  REPLICATION SLAVE ON *.* TO 'replication'@'192.168.0.%' IDENTIFIED  BY 'replication';
mysql> flush  privileges;
mysql> change  master to
    ->  master_host='192.168.0.202',
    ->  master_user='replication',
    ->  master_password='replication',
    ->  master_log_file='mysql-bin.000002',
    ->  master_log_pos=106;
mysql> start  slave;

#主主同步配置完毕，查看同步状态Slave_IO和Slave_SQL是YES说明主主同步成功。

在master插入数据测试下：

在backup查看是否同步成功：

可以看到已经成功同步过去，同样在backup插入到user表数据，一样同步过去，双主就做成功了。

2、配置keepalived实现热备

[root@backup ~]# yum install -y pcre-devel openssl-devel popt-devel #安装依赖包

[root@master ~]# wget http://www.keepalived.org/software/keepalived-1.2.7.tar.gz 
[root@master ~]# tar -xf keepalived-1.2.7.tar.gz -C /usr/local/src/
[root@master ~]# cd /usr/local/
[root@master ~]# ln -sv /usr/local/src/keepalived-1.2.7/ keepalived  #根据实际情况修改 
[root@master ~]# cd keepalived
[root@master ~]#./configure --prefix=/usr/local/keepalived
make && make install

#将keepalived配置成系统服务

[root@master ~]# cp /usr/local/etc/rc.d/init.d/keepalived /etc/init.d/
chmod +x /etc/init.d/keepalived  
[root@master ~]# cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/ [root@master ~]# chkconfig --add keepalived [root@master ~]# chkconfig keepalived on [root@master ~]# mkdir /etc/keepalived [root@master ~]# cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/ [root@master ~]# cp /usr/local/sbin/keepalived /usr/sbin/ #或者ln -s /usr/local/sbin/keepalived /usr/sbin/

配置keepalived
我们自己在新建一个配置文件，默认情况下keepalived启动时会去/etc/keepalived目录下找配置文件

1. [root@master ~]# vi /etc/keepalived/keepalived.conf  
   global_defs {    
        notification_email { [email protected] } notification_email_from [email protected] smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id MYSQL_HA #标识，双主相同 } vrrp_instance VI_1 { state BACKUP #两台配置此处均是BACKUP interface eth0 virtual_router_id 51 #主备相同 priority 100 #优先级，另一台backup改为90 advert_int 1 nopreempt #不抢占，只在优先级高master的机器上设置即可，优先级低backup的机器不设置 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.1.200 } } virtual_server 192.168.1.200 3306 { delay_loop 2 #每个2秒检查一次real_server状态 #lb_algo wrr #LVS算法，用不到，我们就关闭了 #lb_kind DR #LVS模式,如果不关闭，备用服务器不能通过VIP连接主MySQL persistence_timeout 60 #会话保持时间，同一IP的连接60秒内被分配到同一台真实服务器 protocol TCP real_server 192.168.1.201 3306 { #检测本地mysql，backup也要写检测本地mysql weight 3 notify_down /usr/local/keepalived/mysql.sh #当mysq服down时，执行此脚本，杀死keepalived实现切换 TCP_CHECK { connect_timeout 10 #连接超时时间 nb_get_retry 3 #重连次数 delay_before_retry 3 #重连间隔时间 connect_port 3306 #健康检查端口 } } }

编写检测服务down后所要执行的脚本
[root@master ~]# vi /usr/local/keepalived/mysql.sh
#!/bin/bash
pkill keepalived [root@master ~]# chmod +x /usr/local/keepalived/mysql.sh [root@master ~]# /etc/init.d/keepalived start

注：此脚本是上面配置文件notify_down选项所用到的，keepalived使用notify_down选项来检查real_server 的服务状态，当发现real_server服务故障时，便触发此脚本；我们可以看到，脚本就一个命令，通过pkill keepalived强制杀死keepalived进程，从而实现了MySQL故障自动转移。另外，我们不用担心两个MySQL会同时提供数据更新操作， 因为每台MySQL上的keepalived的配置里面只有本机MySQL的IP+VIP，而不是两台MySQL的IP+VIP

启动keepalived

[root@master ~]# /usr/local/keepalived/sbin/keepalived –D     或者/etc/init.d/keepalived start
[root@master ~]# ps -aux | grep keepalived

测试
找一台局域网PC，然后去ping  MySQL的VIP，这时候MySQL的VIP是可以ping的通的
停止MySQL服务，看keepalived健康检查程序是否会触发我们编写的脚本

#backup服务器只修改priority为90、nopreempt不设置、real_server设置本地IP。

#授权两台Mysql服务器允许root远程登录，用于在其他服务器登陆测试！

mysql> grant all on *.* to'root'@'192.168.0.%' identified by '123.com';

mysql> flush privileges;

3、测试高可用性

1、通过Mysql客户端通过VIP连接，看是否连接成功。

2、停止master这台mysql服务，是否能正常切换过去，可通过ip addr命令来查看VIP在哪台服务器上。

3、可通过查看/var/log/messges日志，看出主备切换过程

4、master服务器故障恢复后，是否主动抢占资源，成为活动服务器。

附：keepalived-1.2.7 keepalived实现服务高可用 http://down.51cto.com/data/2440924 

---------------------------------------------------------------------------------------------

针对网卡做bond的做VIP: https://blog.51cto.com/sf1314/2073519 

[root@master ~]# vi /etc/keepalived/keepalived.conf  
global_defs {    
     notification_email { [email protected] } notification_email_from [email protected] smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id MYSQL_HA #标识，双主相同 } vrrp_instance VI_1 { state BACKUP #两台配置此处均是BACKUP interface bond0.101 #------->这边指定配置的聚合网卡bond0.101 virtual_router_id 51 #主备相同 priority 100 #优先级，另一台backup改为90 advert_int 1 nopreempt #不抢占，只在优先级高master的机器上设置即可，优先级低backup的机器不设置 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 10.104.101.13/24 #------->这边设置虚拟的VIP地址 } } virtual_server 10.104.101.13/24 3306 { #--------->指定虚拟VIP地址的配置信息 delay_loop 2 #每个2秒检查一次real_server状态 #lb_algo wrr #LVS算法，用不到，我们就关闭了 #lb_kind DR #LVS模式,如果不关闭，备用服务器不能通过VIP连接主MySQL persistence_timeout 60 #会话保持时间，同一IP的连接60秒内被分配到同一台真实服务器 protocol TCP real_server 10.104.101.12 3306 { #10.104.101.12指本地配置的IP地址，检测本地mysql，backup也要写检测本地mysql weight 3 notify_down /usr/local/keepalived/mysql.sh #当mysq服down时，执行此脚本，杀死keepalived实现切换 TCP_CHECK { connect_timeout 10 #连接超时时间 nb_get_retry 3 #重连次数 delay_before_retry 3 #重连间隔时间 connect_port 3306 #健康检查端口 } } }

 

附：修改mysql账户下的replication的密码可以参考本文章：https://blog.51cto.com/sf1314/2094562