Keepalived VIP自动切换

Keepalived VIP切换的两种情况：

1.keepalived 进程被停止。

2.keepalived中track_script检测失败。

haproxy 检测：

vrrp_script chk_haproxy {
  script "killall -0 haproxy"    # cheaper than pidof
  interval 2                # check every 2 seconds
  weight -2
}

切换相关日志：tail -f /var/log/messages

Keepalived_vrrp[32408]: VRRP_Script(chk_haproxy) failed
Keepalived_vrrp[32408]: VRRP_Instance(VI_1) Received higher prio advert
Keepalived_vrrp[32408]: VRRP_Instance(VI_1) Entering BACKUP STATE
Keepalived_vrrp[32408]: VRRP_Instance(VI_1) removing protocol VIPs.
Keepalived_vrrp[32408]: VRRP_Script(chk_haproxy) succeeded
Keepalived_vrrp[32408]: VRRP_Instance(VI_1) forcing a new MASTER election
Keepalived_vrrp[32408]: VRRP_Instance(VI_1) forcing a new MASTER election
Keepalived_vrrp[32408]: VRRP_Instance(VI_1) Transition to MASTER STATE
Keepalived_vrrp[32408]: VRRP_Instance(VI_1) Entering MASTER STATE
Keepalived_vrrp[32408]: VRRP_Instance(VI_1) setting protocol VIPs.
Keepalived_vrrp[32408]: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth1 for 10.1.1.56
Keepalived_vrrp[32408]: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth1 for 10.1.1.56

切换失败的情况：

keepalived 进程被停止时VIP可以正常切换，keepalived 进程运行状态下，haproxy相关服务停止后，VIP未如期进行切换。

分析：

停止haproxy服务，手动执行killall -0 haproxy && echo "success" || echo "fail"，返回结果是success。

停止haproxy服务后，ps aux |grep haproxy发现还有一个正常启动的haproxy，killall -9 haproxy后发现 tail -f /var/log/messages 出现VIP正常切换的日志。

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