Centos Install keepalived

2. keepalived Introduction
   Keepalived's role is to detect the status of the Web server, if a Web server crashes, or work fails, keepalived will detect and remove the failed Web server from the system, when the Web server is working properly keepalived automatically b servers joined to the server farm, all of these tasks are completed automatically, do not require manual intervention, need to manually do is to repair the failed Web server.
   
   Keepalived can also do dual-machine, when the primary keepalived server down, can automatically switch to the backup keepalived server to provide services.
4. Installation
   Yum-y Install Kernel-headers Kernel-devel
   Yum-y Install popt LIBNL libnl-devel popt-static
   Yum-y Install Ipvsadm
   Yum-y Install keepalived
5. Modifying a configuration file
   Vi/etc/keepalived/keepalived.conf
   

   ! Configuration File forKeepalivedglobal_defs {notification_email {616043155@qq. com #设置报警邮件地址, you can set multiple, 1 per line, [email protected] #需开启邮件报警及本机的Sendmail服务. } #notification_email_from616043155@qq. com #smtp_server smtp.qq.com #设置SMTP server address; #smtp_connect_timeout -router_id Lvs_devel} ####### #VRRP instance####### #vrrp_instance vi_1 {State MASTER #指定Keepalived的角 The master is the host server, backup is the standby server interface eth0 virtual_router_idWuyi#虚拟路由的id号, generally not more than 255 of the priority -#定义优先级, the higher the number, the higher the priority, the primary Dr must be larger than the standby Dr. Advert_int1Authentication {Auth_type Pass #设置验证类型, mainly have pass and ah two kinds of auth_pass Passwd #设置验证密码} virtual_ipad Dress {10.10.0.116#设置主DR的虚拟IP地址 (Virtual IP), multi-set, but must be 1} per line

   keepalived Code

   Note:

   When Keepalived is started, the VIP is not visible through ifconfig, but can be seen through the IP a command
   When Master is down, BACKUP is upgraded to master, and these vrrp_instance state transitions can be recorded in/var/log/message

   Copy the configuration file to the backup server and modify the initial status to priority

   vrrp_instance vi_1 {State    BACKUP    // initialization status     interface eth0               #定义优先级, must be 1 lower than Master's priority          Authentication {        Auth_type PASS          auth_pass Passwd      }    virtual_ipaddress {        10.10 . 0.116       }}

   keepalived Backup Code

   Start the service
   Service keepalived Restart
   Check the keepalived log file
   Stop or shut down the keepalived service, tail-f/var/log/message check log condition in master server

7. Reference links
   http://lanlian.blog.51cto.com/6790106/1303195
   http://beyondhdf.blog.51cto.com/229452/1331874

Centos Install keepalived