解决nginx负载均衡高可用keepalived只针对物理机的问题

在高可用keepalived软件，在默认的情况下仅仅在对方机器宕机或keepalived停掉的时候才会接管业务。

但是在实际工作过程中，例如在nginx负载均衡工作实例中，nginx服务已停止，而keepalived服务还在

工作的情况，这会导致用户访问VIP，而找不到对应的服务。

例如：

主机IP：10.0.0.5/24

备机IP：10.0.0.6/24

VIP:10.0.0.100/24

方法一：直接在主机上写守护脚本，来对nginx服务进行监控

1、脚本内容如下：

 [root@lb01 scripts]# cat check_nginx.sh

 #!/bin/bash

 #-------------CopyRight-------------

 #   Name:check nginx server

 #   Version Number:1.00

 #   Type:sh

 #   Language:bash shell

 #   Date:--

 #   Author:sandy

 #   QQ:

 #   Email:eeexu123@.com

 #   Blog:https://www.cnblogs.com/eeexu123/

 while true

 do

     if [ `netstat -tulnp|grep nginx|wc -l` -ne  ];then

         /etc/init.d/keepalived stop

     fi

     sleep

 done

2、然后，直接运行此脚本，每五秒进行一次检测nginx服务是否在线。

 [root@lb01 scripts]# sh check_nginx.sh &

 []

 [root@lb01 scripts]# ps -ef |grep check_nginx

 root           : pts/    :: sh check_nginx.sh

 root           : pts/    :: grep check_nginx

3、测试

1）查看主机VIP是否在线

  [root@lb01 ~]# ifconfig

  eth0      Link encap:Ethernet  HWaddr :0C::2C::BB

            inet addr:10.0.0.5  Bcast:10.0.0.255  Mask:255.255.255.0

            inet6 addr: fe80::20c:29ff:fe2c:bb/ Scope:Link

            UP BROADCAST RUNNING MULTICAST  MTU:  Metric:

            RX packets: errors: dropped: overruns: frame:

            TX packets: errors: dropped: overruns: carrier:

            collisions: txqueuelen:

            RX bytes: (32.2 MiB)  TX bytes: (4.9 MiB)

 eth0:    Link encap:Ethernet  HWaddr :0C::2C::BB

           inet addr:10.0.0.100  Bcast:0.0.0.0  Mask:255.255.255.0

           UP BROADCAST RUNNING MULTICAST  MTU:  Metric:

 eth1      Link encap:Ethernet  HWaddr :0C::2C::C5

           inet addr:172.16.1.5  Bcast:172.16.1.255  Mask:255.255.255.0

           inet6 addr: fe80::20c:29ff:fe2c:c5/ Scope:Link

           UP BROADCAST RUNNING MULTICAST  MTU:  Metric:

           RX packets: errors: dropped: overruns: frame:

           TX packets: errors: dropped: overruns: carrier:

           collisions: txqueuelen:

           RX bytes: (790.8 KiB)  TX bytes: (37.9 KiB)

 lo        Link encap:Local Loopback

           inet addr:127.0.0.1  Mask:255.0.0.0

           inet6 addr: ::/ Scope:Host

           UP LOOPBACK RUNNING  MTU:  Metric:

           RX packets: errors: dropped: overruns: frame:

           TX packets: errors: dropped: overruns: carrier:

           collisions: txqueuelen:

           RX bytes: (0.0 b)  TX bytes: (0.0 b)

2）停止nginx服务

 [root@lb01 ~]# /application/nginx/sbin/nginx -s stop

 [root@lb01 ~]# netstat -tulnp

 Active Internet connections (only servers)

 Proto Recv-Q Send-Q Local Address               Foreign Address             State       PID/Program name

 tcp               0.0.0.0:                  0.0.0.0:*                   LISTEN      /sshd

 tcp               127.0.0.1:                0.0.0.0:*                   LISTEN      /master

 tcp               :::                       :::*                        LISTEN      /sshd

 tcp               :::                      :::*                        LISTEN      /master

3）查看VIP是否漂移

主机IP：

 1 [root@lb01 ~]# ifconfig

 2 eth0      Link encap:Ethernet  HWaddr 00:0C:29:2C:00:BB

 3           inet addr:10.0.0.5  Bcast:10.0.0.255  Mask:255.255.255.0

 4           inet6 addr: fe80::20c:29ff:fe2c:bb/64 Scope:Link

 5           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

 6           RX packets:41555 errors:0 dropped:0 overruns:0 frame:0

 7           TX packets:26526 errors:0 dropped:0 overruns:0 carrier:0

 8           collisions:0 txqueuelen:1000

 9           RX bytes:33803135 (32.2 MiB)  TX bytes:5182305 (4.9 MiB)

10

11 eth1      Link encap:Ethernet  HWaddr 00:0C:29:2C:00:C5

12           inet addr:172.16.1.5  Bcast:172.16.1.255  Mask:255.255.255.0

13           inet6 addr: fe80::20c:29ff:fe2c:c5/64 Scope:Link

14           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

15           RX packets:8854 errors:0 dropped:0 overruns:0 frame:0

16           TX packets:311 errors:0 dropped:0 overruns:0 carrier:0

17           collisions:0 txqueuelen:1000

18           RX bytes:811478 (792.4 KiB)  TX bytes:38876 (37.9 KiB)

19

20 lo        Link encap:Local Loopback

21           inet addr:127.0.0.1  Mask:255.0.0.0

22           inet6 addr: ::1/128 Scope:Host

23           UP LOOPBACK RUNNING  MTU:65536  Metric:1

24           RX packets:0 errors:0 dropped:0 overruns:0 frame:0

25           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0

26           collisions:0 txqueuelen:0

27           RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

备机IP

 1 [root@lb02 ~]# ifconfig

 2 eth0      Link encap:Ethernet  HWaddr 00:0C:29:93:72:8D

 3           inet addr:10.0.0.6  Bcast:10.0.0.255  Mask:255.255.255.0

 4           inet6 addr: fe80::20c:29ff:fe93:728d/64 Scope:Link

 5           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

 6           RX packets:40535 errors:0 dropped:0 overruns:0 frame:0

 7           TX packets:23552 errors:0 dropped:0 overruns:0 carrier:0

 8           collisions:0 txqueuelen:1000

 9           RX bytes:33425626 (31.8 MiB)  TX bytes:4173830 (3.9 MiB)

10

11 eth0:1    Link encap:Ethernet  HWaddr 00:0C:29:93:72:8D

12           inet addr:10.0.0.100  Bcast:0.0.0.0  Mask:255.255.255.0

13           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

14

15 eth1      Link encap:Ethernet  HWaddr 00:0C:29:93:72:97

16           inet addr:172.16.1.6  Bcast:172.16.1.255  Mask:255.255.255.0

17           inet6 addr: fe80::20c:29ff:fe93:7297/64 Scope:Link

18           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

19           RX packets:8608 errors:0 dropped:0 overruns:0 frame:0

20           TX packets:56 errors:0 dropped:0 overruns:0 carrier:0

21           collisions:0 txqueuelen:1000

22           RX bytes:781127 (762.8 KiB)  TX bytes:6646 (6.4 KiB)

23

24 lo        Link encap:Local Loopback

25           inet addr:127.0.0.1  Mask:255.0.0.0

26           inet6 addr: ::1/128 Scope:Host

27           UP LOOPBACK RUNNING  MTU:65536  Metric:1

28           RX packets:0 errors:0 dropped:0 overruns:0 frame:0

29           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0

30           collisions:0 txqueuelen:0

31           RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

由上述可知，VIP发生漂移。keepalived触发脚本执行成功。

方法二：可以使用keepalived的配置文件来触发已写好的脚本

1、脚本内容如下：

 [root@lb01 scripts]# cat keep_nginx.sh

 #!/bin/bash

 #-------------CopyRight-------------

 #   Name:check nginx server

 #   Version Number:1.00

 #   Type:sh

 #   Language:bash shell

 #   Date:--

 #   Author:sandy

 #   QQ:

 #   Email:eeexu123@.com

 #   Blog:https://www.cnblogs.com/eeexu123/

 if [ `netstat -tulnp|grep nginx|wc -l` -ne  ];then

     /etc/init.d/keepalived stop

 fi

2、将脚本加上可执行权限

[root@lb01 scripts]# chmod +x keep_nginx.sh

 [root@lb01 scripts]# ll

 总用量

 -rw-r--r--.  root root  7月    : check_nginx.sh

 -rwxr-xr-x.  root root  7月    : keep_nginx.sh

3、在主机的keepalived的配置文件上，做如下修改

　　/etc/keepalived/keepalived.conf配置文件如下：

　　绿色部分内容是新添加触发脚本

 ! Configuration File for keepalived

 global_defs {

    notification_email {

      eeexu123@.com

    }

    notification_email_from Alexandre.Cassen@firewall.loc

    smtp_server 127.0.0.1

    smtp_connect_timeout

    router_id lb01

 }

 vrrp_script chk_nginx_proxy {

     script "/server/scripts/keep_nginx.sh"

     interval

     weight

 }

 vrrp_instance VI_1 {

     state MASTER

     interface eth0

     virtual_router_id

     priority

     advert_int

     authentication {

         auth_type PASS

         auth_pass

     }

     virtual_ipaddress {

         10.0.0.100/ dev eth0 label eth0:

     }

32     track_script {

         chk_nginx_proxy

     }

 }

4、说明：

vrrp_script chk_nginx_proxy {                    #定义vrrp脚本

    script "/server/scripts/keep_nginx.sh"       #执行keep_nginx.sh脚本，当nginx服务有问题时，就停止keepalived服务

    interval 2                                   #间隔两秒检查一次

    weight

}

track_script { #触发检查
chk_nginx_proxy
}

5、测试

1）查看主机中的VIP是否在线

 [root@lb01 ~]# ifconfig

 eth0      Link encap:Ethernet  HWaddr :0C::2C::BB

           inet addr:10.0.0.5  Bcast:10.0.0.255  Mask:255.255.255.0

           inet6 addr: fe80::20c:29ff:fe2c:bb/ Scope:Link

           UP BROADCAST RUNNING MULTICAST  MTU:  Metric:

           RX packets: errors: dropped: overruns: frame:

           TX packets: errors: dropped: overruns: carrier:

           collisions: txqueuelen:

           RX bytes: (32.2 MiB)  TX bytes: (4.9 MiB)

 eth0:    Link encap:Ethernet  HWaddr :0C::2C::BB

           inet addr:10.0.0.100  Bcast:0.0.0.0  Mask:255.255.255.0

           UP BROADCAST RUNNING MULTICAST  MTU:  Metric:

 eth1      Link encap:Ethernet  HWaddr :0C::2C::C5

           inet addr:172.16.1.5  Bcast:172.16.1.255  Mask:255.255.255.0

           inet6 addr: fe80::20c:29ff:fe2c:c5/ Scope:Link

           UP BROADCAST RUNNING MULTICAST  MTU:  Metric:

           RX packets: errors: dropped: overruns: frame:

           TX packets: errors: dropped: overruns: carrier:

           collisions: txqueuelen:

           RX bytes: (790.8 KiB)  TX bytes: (37.9 KiB)

 lo        Link encap:Local Loopback

           inet addr:127.0.0.1  Mask:255.0.0.0

           inet6 addr: ::/ Scope:Host

           UP LOOPBACK RUNNING  MTU:  Metric:

           RX packets: errors: dropped: overruns: frame:

           TX packets: errors: dropped: overruns: carrier:

           collisions: txqueuelen:

           RX bytes: (0.0 b)  TX bytes: (0.0 b)