MYSQL + MHA +keepalive + VIP安装配置(三)--keepalived安装配置

一、概述

　　keepalived介绍：Keepalived的作用是检测web服务器的状态，如果有一台web服务器死机，或工作出现故障，Keepalived将检测到，并将有故障的web 服务器从系统中剔除，当web服务器工作正常后Keepalived自动将web服务器加入到服务器群中，这些工作全部自动完成，不需要人工干涉，需要人 工做的只是修复故障的web服务器。

二、环境

vip:192.168.1.203204
mysql-master:192.168.1.231
mysql-slave:192.168.1.232

三、keepalived安装

安装步骤两台机mysql-master、mysql-slave一样，如下：

1、下载地址：http://www.keepalived.org/software/keepalived-1.2.12.tar.gz

shell>wget http://www.keepalived.org/software/keepalived-1.2.12.tar.gz

2、安装环境

yum -y install openssl-devel

 否则会报如下错误

configure: error:
  !!! OpenSSL is not properly installed on your system. !!!
  !!! Can not include OpenSSL headers files.

3、安装

shell>tar -zxvf  keepalived-1.2.12.tar.gz
shell>cd keepalived-1.2.12
shell>./configure --prefix=/opt/keepalived --with-kernel-dir=/usr/src/kernels/2.6.32-431.el6.x86_64/
shell>make 
shell>make install

 说明：

 --prefix：安装路径

 --with-kernel-dir：这个是重要的参数，这个参数并不表示我们要把Keepalived统进内核，而是指使用内核源码里面的头文件，也就是include目录。

  2.6.32-431.el6.x86_64可以通过

shell>uname -r 命令查看到

 4、配置

# cp /opt/keepalived/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/
# cp /opt/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
# mkdir /etc/keepalived
# cp /opt/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/
# cp /opt/keepalived/sbin/keepalived /usr/sbin/

 5、启动/停止

shell>service keepalived start
shell>service keepalived stop
shell>service keepalived restart

四、keepalived配置

1、mysql-master:192.168.1.231的配置

shell>vim /etc/keepalived/keepalived.conf

 配置如下：

global_defs {
 router_id mysql-master #修改为自己的主机名
 notification_email {
 mengtao10@163.com   #接收邮件，可以有多个，一行一个
}
 #当主、备份设备发生改变时，通过邮件通知
 notification_email_from lzyangel@126.com
 #发送邮箱服务器
 smtp_server stmp.163.com
 #发送邮箱超时时间
 smtp_connect_timeout 30
 }
##################第一部分###################
vrrp_instance VI_1 {
     state BACKUP    #都修改成BACKUP
     interface eth0    #绑定的网卡
     virtual_router_id 60 #默认51 主从都修改为60
     priority 100            #优先级，在mysql-slave上LVS上修改成80
     advert_int 1
     nopreempt #不抢占资源，意思就是它活了之后也不会再把主抢回来
  
     authentication {
     # 认证方式，可以是PASS或AH两种认证方式
     auth_type PASS
     # 认证密码
     auth_pass 1111
     }
virtual_ipaddress {
     192.168.1.203
     192.168.1.204  #这可以增加多个VIP
     }
}
##################第二部分###################
virtual_server 192.168.1.203 3306 {
     delay_loop 6
     lb_algo wrr
     lb_kind DR
     nat_mask 255.255.255.0
     persistence_timeout 50
     protocol TCP
    real_server 192.168.1.231 3306 {
     weight 1
     notify_down /root/mysql_down.sh
     TCP_CHECK {
         connect_timeout 10
         nb_get_retry 3
         connect_port 3306
         }
     }
}

 2、mysql-master:192.168.1.232的配置

shell>vim /etc/keepalived/keepalived.conf

 配置如下：

global_defs {
 router_id mysql-master #修改为自己的主机名
 notification_email {
 mengtao10@163.com   #接收邮件，可以有多个，一行一个
}
 #当主、备份设备发生改变时，通过邮件通知
 notification_email_from lzyangel@126.com
 #发送邮箱服务器
 smtp_server stmp.163.com
 #发送邮箱超时时间
 smtp_connect_timeout 30
 }
##################第一部分###################
vrrp_instance VI_1 {
     state BACKUP    #都修改成BACKUP
     interface eth0    #绑定的网卡
     virtual_router_id 60 #默认51 主从都修改为60
     priority 80           #优先级，在mysql-master上LVS上修改成100
     advert_int 1
     authentication {
     # 认证方式，可以是PASS或AH两种认证方式
     auth_type PASS
     # 认证密码
     auth_pass 1111
     }
virtual_ipaddress {
     192.168.1.203
     192.168.1.204  #这可以增加多个VIP
     }
}
##################第二部分###################
virtual_server 192.168.1.203 3306 {
     delay_loop 6
     lb_algo wrr
     lb_kind DR
     nat_mask 255.255.255.0
     persistence_timeout 50
     protocol TCP
    real_server 192.168.1.232 3306 {
     weight 1
     notify_down /root/mysql_down.sh
     TCP_CHECK {
         connect_timeout 10
         nb_get_retry 3
         connect_port 3306
         }
     }
}

 3、myslq_down.sh配置，两台机都要配置这一步！！！

    这里需要注意的是，notify_down /root/mysql_down.sh这个选项，这个是是在keepalived检测不到mysql的时候要执行的脚本，从上面的配置文件来看real服务器只有本机。那么，keeaplived如果启动，客户端也只是访问本机的mysql。nopreempt这个选下也得注意，这个是不抢占资源在优先级高的机器上配置就可以。
看下这个脚本的内容：

# vim /root/mysql_down.sh
#!/bin/bash
pkill keepalived
# chmod +x /root/mysql_down.sh #授权可执行权限

 脚本内容就一条命令：pkill keepalived，主要作用是如果本机的mysql挂掉了，那么同时会杀死本机的keepalived，这样另外一台就会接替他工作，虚拟IP也会被另一台接管，如果不杀死keepalived虚拟IP不会被另一台接管，mysql访问也就不会切换过去。

 注意：必须要先启动MYSQL,再启动keepalived，否则keepalived启动后会运行mysql_down.sh脚本，等于自杀。

4、mysql-master(231)启动后查看IP的绑定情况，如下：

shell> ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 08:00:27:cc:92:22 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.232/24 brd 192.168.1.255 scope global eth0
    inet 192.168.1.203/32 scope global eth0
    inet 192.168.1.204/32 scope global eth0
    inet6 fe80::a00:27ff:fecc:9222/64 scope link 
       valid_lft forever preferred_lft forever

五、测试

1、231、232两台机同时启动MYSQL及Keepalived.

   通过win cmd 命令行的客户端(或程序)连接VIP：192.168.1.203或204，如下：

C:UsersDuncan>mysql -h192.168.1.203 -usunney -psunney
Welcome to the MySQL monitor.  Commands end with ; or g.
Your MySQL connection id is 1440
Server version: 5.5.37-log MySQL Community Server (GPL)

Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sunney             |
| test               |
+--------------------+
5 rows in set (0.04 sec)

mysql>

注意：这时存储的数据库是mysql-master(192.168.1.231)因为他是主库。配置 priority 100 优先级高。

2、mysql-slave(232)的机同时关闭MYSQL及Keepalived.这时关闭上以上的是一样的。因为他没有走这个库。

3、mysql-master(231)同时关闭MYSQL及Keepalived,mysql-slave(232)同时启动MYSQL及Keepalived

    切换很快，大概在2到3秒之间！

   通过win cmd 命令行的客户端(或程序)连接VIP：192.168.1.203或204，如下：

C:UsersDuncan>mysql -h192.168.1.203 -usunney -psunney
Welcome to the MySQL monitor.  Commands end with ; or g.
Your MySQL connection id is 1440
Server version: 5.5.37-log MySQL Community Server (GPL)
Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sunney             |
| test               |
+--------------------+
5 rows in set (0.04 sec)

mysql>

 成功！