【Mysql】keepalive的安装与配置

参考文档：
http://blog.jobbole.com/100390/
http://lanlian.blog.51cto.com/6790106/1303195


环境：主库：192.168.6.119
         备库：192.168.6.121
         vip：  192.168.6.120


1 master与slave端都安装keepalive

1. [root@MYSQL src]# wget http://www.keepalived.org/software/keepalived-1.2.12.tar.gz
   
2. [root@MYSQL src]# tar -xf keepalived-1.2.12.tar.gz 
   
3. [root@MYSQL src]# cd keepalived-1.2.12
   
4. [root@MYSQL src]# yum -y install gcc gcc-c++ gcc-g77 ncurses-devel bison libaio-devel cmake libnl* libpopt* popt-static openssl-devel
   
5. [root@MYSQL keepalived-1.2.12]# ./configure
   
6. [root@MYSQL keepalived-1.2.12]# make && make install
   
7. [root@MYSQL src]#mkdir /etc/keepalived/
   
8.  
   
9. [root@MYSQL src]# cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/
   
10. [root@MYSQL src]# cp /usr/local/etc/rc.d/init.d/keepalived /etc/init.d/
    
11. [root@MYSQL src]# cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/
    
12. [root@MYSQL src]#cp /usr/local/sbin/keepalived /usr/sbin/

2. 配置 keepalived

1. [root@MYSQL keepalived]# vi keepalived.conf 
   
2. ! Configuration File for keepalived
   
3.  
   
4. global_defs {
   
5.    notification_email {
   
6.      acassen@firewall.loc
   
7.      failover@firewall.loc
   
8.      sysadmin@firewall.loc
   
9.    }
   
10.    notification_email_from Alexandre.Cassen@firewall.loc
    
11.    smtp_server 192.168.200.1
    
12.    smtp_connect_timeout 30
    
13.    router_id LVS_DEVEL ##配置是为了标识当前节点，两个节点的此项设置可相同，也可不相同
    
14. }
    

1. vrrp_script chk_http_port {            ---配合脚本使用，比如说检查nginx是否存活，检查mysql是否存活等 
      script "/usr/local/keepalived/nginx.sh" #在这里添加脚本链接 
      interval 3       #脚本执行间隔 
      weight -2         #脚本结果导致的优先级变更  ###如果检测返回值不为真weight -2 表示减2，权重值降低，backup server权重值（99）>现Master（100-2）的，切换
   }
   
2. 
   

1. vrrp_instance VI_1 {
   
2.     state MASTER                   #指定A节点为主节点 备用节点上设置为BACKUP即可
3.     interface eth0
   
4.     virtual_router_id 51              #VRRP组名，两个节点的设置必须一样，以指明各个节点属于同一VRRP
   
5.     priority 100              #主节点的优先级（1-254之间），备用节点必须比主节点优先级低 
   
6.    ###nopreempt                     ###这个参数也可以防止切换到从库后，主keepalived恢复后自动切换回主库
7.          advert_int 1
   
8.     authentication {             #设置验证信息，两个节点必须一致
   
9.         auth_type PASS 
   
10.         auth_pass 1111
    
11.     }
    
12. 
    

 track_script {
        chk_http_port     #添加脚本执行
    }

1. virtual_ipaddress {
   
2. 192.168.6.120                   =====vip，指定一个或多个vip
   
3.     }
   
4. }

上面的脚本简单的查看http进程是否存在，不存在就退出返回假。

点击(此处)折叠或打开

1. #!/bin/bash
   A=`netstat -nputl|grep -i 80 |wc -l`
   if [ $A -eq 0 ];then
      exit 1;
      #/etc/init.d/keepalived stop
   fi
   

1. 实验一：
2. master与backup ip分别如下
3. [root@node1 keepalived]# ip a
   2: eth0: mtu 1500 qdisc pfifo_fast qlen 1000
       link/ether 08:00:27:7a:c6:9c brd ff:ff:ff:ff:ff:ff
       inet 192.168.6.114/24 brd 192.168.6.255 scope global eth0
       inet 192.168.6.120/32 scope global eth0
       inet6 fe80::a00:27ff:fe7a:c69c/64 scope link 
          valid_lft forever preferred_lft forever
   [root@node2 keepalived]# ip a
   2: eth0: mtu 1500 qdisc pfifo_fast qlen 1000
       link/ether 08:00:27:03:1b:a1 brd ff:ff:ff:ff:ff:ff
       inet 192.168.6.115/24 brd 192.168.6.255 scope global eth0
       inet6 fe80::a00:27ff:fe03:1ba1/64 scope link 
          valid_lft forever preferred_lft forever
   
   
4. 
   
5. 关闭主库http
6. [root@node1 keepalived]# /etc/init.d/httpd stop
   Stopping httpd:                                            [  OK  ]
   
   
7. 主库与从库ip：
8. [root@node1 keepalived]# ip a
   2: eth0: mtu 1500 qdisc pfifo_fast qlen 1000
       link/ether 08:00:27:7a:c6:9c brd ff:ff:ff:ff:ff:ff
       inet 192.168.6.114/24 brd 192.168.6.255 scope global eth0
       inet6 fe80::a00:27ff:fe7a:c69c/64 scope link 
          valid_lft forever preferred_lft forever
9. [root@node2 keepalived]# ip a
   2: eth0: mtu 1500 qdisc pfifo_fast qlen 1000
       link/ether 08:00:27:03:1b:a1 brd ff:ff:ff:ff:ff:ff
       inet 192.168.6.115/24 brd 192.168.6.255 scope global eth0
       inet 192.168.6.120/32 scope global eth0                          ---vip飘到从库了
       inet6 fe80::a00:27ff:fe03:1ba1/64 scope link 
          valid_lft forever preferred_lft forever
   
   
   
10. 恢复主库http
11. [root@node1 keepalived]# /etc/init.d/httpd start
    Starting httpd:                                            [  OK  ]
12. 主库与从库ip：
13. [root@node1 keepalived]# ip a
    2: eth0: mtu 1500 qdisc pfifo_fast qlen 1000
        link/ether 08:00:27:7a:c6:9c brd ff:ff:ff:ff:ff:ff
        inet 192.168.6.114/24 brd 192.168.6.255 scope global eth0
        inet 192.168.6.120/32 scope global eth0                            ---vip又飘回主库了
        inet6 fe80::a00:27ff:fe7a:c69c/64 scope link 
           valid_lft forever preferred_lft forever
    [root@node2 keepalived]# ip a
    2: eth0: mtu 1500 qdisc pfifo_fast qlen 1000
        link/ether 08:00:27:03:1b:a1 brd ff:ff:ff:ff:ff:ff
        inet 192.168.6.115/24 brd 192.168.6.255 scope global eth0
        inet6 fe80::a00:27ff:fe03:1ba1/64 scope link 
           valid_lft forever preferred_lft forever
14. 
    
      nopreempt 参数的作用：静止vip再飘回来（少用，根据情况配置）

    1. node1	node2	vip漂移过程（关闭主库http，恢复主库http）	原因
       无nopreempt	无nopreempt	node1》node2》node1
       nopreempt	无nopreempt	node1》node2》node2（vip不飘了）	node1静止vip飘回去
       无nopreempt	nopreempt	一直在node1上，飘不动	node2静止vip飘过去
       nopreempt	nopreempt	一直在nide1上，漂不动	node2静止vip飘过去

       
       
       

实验二：

1. 配置文件为
   
   1. [root@node1 keepalived]# more keepalived.conf
      ! Configuration File for keepalived
       
      global_defs {
         notification_email {
           acassen@firewall.loc
           failover@firewall.loc
           sysadmin@firewall.loc
         }
         notification_email_from Alexandre.Cassen@firewall.loc
         smtp_server 192.168.200.1
         smtp_connect_timeout 30
         router_id LVS_DEVEL
      }
      
      
      vrrp_script chk_http_port {      
         script "/usr/local/keepalived/nginx.sh"     
      }
      
      
      vrrp_instance VI_1 {
          state MASTER
          interface eth0
          virtual_router_id 51    
          priority 99           
               advert_int 1
          authentication {      
              auth_type PASS 
              auth_pass 1111
          }
      
      
       track_script {
              chk_http_port    
          }
      virtual_ipaddress {
      192.168.6.120           
          }
      }
      
      
   脚本改为：若http服务失效，则kill keepalive进程
2. 
   
   1. #!/bin/bash
      A=`netstat -nputl|grep -i 80 |wc -l`
      if [ $A -eq 0 ];then
         #exit 1;
         /etc/init.d/keepalived stop
      fi
      
   
   和实验一的效果一样：vip先飘到从库，恢复http后，启动keepalive后又飘回主库，要想不飘回主库，改小权重

实验一二的区别：一个是通过权重来控制vip的飘逸。一个直接是控制keepalive进程的存活来控制vip的飘逸



3.如何在状态转换时进行通知？

1.要在状态转换是进行通知，需要定义通知脚本可以在

vrrp_sync_group{

}中定义，也可以在

vrrp_instance{

｝中定义

通过man keepalived命令可以查看通知脚本定义的两种方法

第一种

# to MASTER transition

notify_master /path/to_master.sh

# to BACKUP transition

notify_backup /path/to_backup.sh

# FAULT transition

notify_fault "/path/fault.sh VG_1"

第二种

#arguments

# $1 ="GROUP"|"INSTANCE"

# $2 = name of group or instance

# $3 = target state of transition

# ("MASTER"|"BACKUP"|"FAULT")

notify /path/notify.sh

下面用一个脚本notify.sh实现状态转换通知的简单示例：

#!/bin/bash
#Author: MageEdu <linuxedu@foxmail.com>
#description: An example of notify script
#
vip=192.168.6.120
contact='root@localhost'
notify(){
    mailsubject="`hostname` to be $1: $vip floating"
    mailbody="`date '+%F %H:%M:%S'`: vrrptransition, `hostname` changed to be $1"
    echo $mailbody | mail -s"$mailsubject" $contact
}
case "$1" in
    master)
        notify master
        exit 0
    ;;
    backup)
        notify backup
        exit 0
    ;;
    fault)
        notify fault
        exit 0
    ;;
    *)
        echo 'Usage: `basename $0`{master|backup|fault}'
        exit 1
    ;;
esac

chmod +x notify.sh 主从配置文件修改

[root@node1 keepalived]# more keepalived.conf
! Configuration File for keepalived
 
global_defs {
   notification_email {
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   smtp_server 192.168.200.1
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}

vrrp_script chk_http_port {
   script "/usr/local/keepalived/nginx.sh"
   interval 3
   weight -2
}

vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 51
    priority 99
# nopreempt
         advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }

 track_script {
        chk_http_port
    }
   

   notify_master "/usr/local/keepalived/notify.sh master"
   notify_backup"/usr/local/keepalived/notify.sh backup"
   notify_fault"/usr/local/keepalived/notify.sh fault"

virtual_ipaddress {
192.168.6.120
    }
}

测试：

关闭主库http服务
[root@node1 ~]# /etc/init.d/httpd stop
Stopping httpd: [ OK ]
[root@node1 ~]# mail
Mail version 8.1 6/6/93. Type ? for help.
"/var/spool/mail/root": 1 message 1 new
>N 1 root@localhost.local Thu Jun 30 21:10 16/716 "node1 to be backup:"
[root@node2 keepalived]# mail
Mail version 8.1 6/6/93.  Type ? for help.
"/var/spool/mail/root": 1 message 1 new
>N  1 root@localhost.local  Thu Jun 30 21:10  16/716   "node2 to be master:"

恢复主库http服务 [root@node1 ~]# mail
Mail version 8.1 6/6/93.  Type ? for help.
"/var/spool/mail/root": 2 messages 1 new 2 unread
 U  1 root@localhost.local  Thu Jun 30 21:10  17/726   "node1 to be backup:"
>N  2 root@localhost.local  Thu Jun 30 21:12  16/716   "node1 to be master:"
   [root@node2 keepalived]# mail
Mail version 8.1 6/6/93.  Type ? for help.
"/var/spool/mail/root": 2 messages 1 new 2 unread
 U  1 root@localhost.local  Thu Jun 30 21:10  17/726   "node2 to be master:"
>N  2 root@localhost.local  Thu Jun 30 21:12  16/716   "node2 to be backup:"

参考文档
http://kaifly.blog.51cto.com/3209616/1665729   --MySQL主库高可用 -- 双主单活故障自动切换方案
http://www.tuicool.com/articles/nYvuYf      ---结合keepalived实现redis群集高可用故障自动切换

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