nginx+keepalived高可用

水深无声 2023-07-09 09:26 59阅读 0赞

**目录**

1 keepalived的安装

2.场景演练

3 高可用验证

--------------------

之前写过nginx核keeaplived的相关部署，以及nginx的负载均衡。那么当nginx服务器挂了的时候，再完美的负载均衡也起不到作用了，下面介绍keepalived实现nginx高可用

### 1 keepalived的安装 ###

之前有写keepalived的编译安装，centos系统已经把keepalived集成了，直接可以yum install安装

### 2.场景演练 ###

<table style="width:500px;"> 
 <tbody> 
  <tr> 
   <td>机器</td> 
   <td>组件</td> 
  </tr> 
  <tr> 
   <td>192.168.52.128</td> 
   <td>nginx&nbsp; keepalived</td> 
  </tr> 
  <tr> 
   <td>192.168.52.128</td> 
   <td>nginx&nbsp; keepalived</td> 
  </tr> 
 </tbody> 
</table>

首先我们搭建好nginx服务，如下所示：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d5bDk1Mjc_size_16_color_FFFFFF_t_70][]![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d5bDk1Mjc_size_16_color_FFFFFF_t_70 1][]

然后配置keepalived.conf文件，如下所示

128机器上的keepalived.conf文件（master节点）

! Configuration File for keepalived
    
    vrrp_script check_nginx_alived {
            #script "/etc/keepalived/scripts/check_nginx.sh"
            script "killall -0 nginx"
            interval 2
    }
    
    vrrp_instance VI_1 {
        state MASTER
        interface ens33
        virtual_router_id 51
        nopreempt
        priority 100
        advert_int 1
        authentication {
            auth_type PASS
            auth_pass 1111
        }
    
        virtual_ipaddress {
            192.168.52.200
        }
    
       track_script {
           check_nginx_alived
       }
    
    }

129机器上的keepalived的配置文件

! Configuration File for keepalived
    
    vrrp_script check_nginx_alived {
            #script "/etc/keepalived/scripts/check_nginx.sh"
            script "killall -0 nginx"
            interval 2
    }
    
    vrrp_instance VI_1 {
        state BACKUP
        interface ens33
        virtual_router_id 51
        nopreempt
        priority 80
        advert_int 1
        authentication {
            auth_type PASS
            auth_pass 1111
        }
    
        virtual_ipaddress {
            192.168.52.200
        }
    
       track_script {
           check_nginx_alived
       }
    }

启动keepalived服务，128上的keepalived日志

[root@wyl01 scripts]# systemctl status keepalived
    ● keepalived.service - LVS and VRRP High Availability Monitor
       Loaded: loaded (/usr/lib/systemd/system/keepalived.service; disabled; vendor preset: disabled)
       Active: active (running) since Fri 2020-02-28 15:41:09 CST; 1s ago
      Process: 49007 ExecStart=/usr/sbin/keepalived $KEEPALIVED_OPTIONS (code=exited, status=0/SUCCESS)
     Main PID: 49008 (keepalived)
       CGroup: /system.slice/keepalived.service
               ├─49008 /usr/sbin/keepalived -D
               ├─49009 /usr/sbin/keepalived -D
               └─49010 /usr/sbin/keepalived -D
    
    Feb 28 15:41:09 wyl01 Keepalived_vrrp[49010]: Opening file '/etc/keepalived/keepalived.conf'.
    Feb 28 15:41:09 wyl01 Keepalived_vrrp[49010]: WARNING - default user 'keepalived_script' for script e...ate.
    Feb 28 15:41:09 wyl01 Keepalived_vrrp[49010]: (VI_1): Warning - nopreempt will not work with initial ...STER
    Feb 28 15:41:09 wyl01 Keepalived_vrrp[49010]: WARNING - script `killall` resolved by path search to `...ath.
    Feb 28 15:41:09 wyl01 Keepalived_vrrp[49010]: SECURITY VIOLATION - scripts are being executed but scr...led.
    Feb 28 15:41:09 wyl01 Keepalived_vrrp[49010]: VRRP_Instance(VI_1) removing protocol VIPs.
    Feb 28 15:41:09 wyl01 Keepalived_vrrp[49010]: Using LinkWatch kernel netlink reflector...
    Feb 28 15:41:09 wyl01 Keepalived_vrrp[49010]: VRRP sockpool: [ifindex(2), proto(112), unicast(0), fd(10,11)]
    Feb 28 15:41:09 wyl01 Keepalived_vrrp[49010]: VRRP_Script(check_nginx_alived) succeeded
    Feb 28 15:41:10 wyl01 Keepalived_vrrp[49010]: VRRP_Instance(VI_1) Transition to MASTER STATE
    Feb 28 15:41:11 wyl01 Keepalived_vrrp[49010]: VRRP_Instance(VI_1) Entering MASTER STATE
    Feb 28 15:41:11 wyl01 Keepalived_vrrp[49010]: VRRP_Instance(VI_1) setting protocol VIPs.
    Feb 28 15:41:11 wyl01 Keepalived_vrrp[49010]: Sending gratuitous ARP on ens33 for 192.168.52.200
    Feb 28 15:41:11 wyl01 Keepalived_vrrp[49010]: VRRP_Instance(VI_1) Sending/queueing gratuitous ARPs on....200
    Feb 28 15:41:11 wyl01 Keepalived_vrrp[49010]: Sending gratuitous ARP on ens33 for 192.168.52.200
    Feb 28 15:41:11 wyl01 Keepalived_vrrp[49010]: Sending gratuitous ARP on ens33 for 192.168.52.200
    Feb 28 15:41:11 wyl01 Keepalived_vrrp[49010]: Sending gratuitous ARP on ens33 for 192.168.52.200
    Feb 28 15:41:11 wyl01 Keepalived_vrrp[49010]: Sending gratuitous ARP on ens33 for 192.168.52.200
    Hint: Some lines were ellipsized, use -l to show in full.

129上的keepalived的启动日志

[root@wyl2 html]# systemctl status keepalived
    ● keepalived.service - LVS and VRRP High Availability Monitor
       Loaded: loaded (/usr/lib/systemd/system/keepalived.service; disabled; vendor preset: disabled)
       Active: active (running) since Fri 2020-02-28 15:42:55 CST; 19s ago
      Process: 116712 ExecStart=/usr/sbin/keepalived $KEEPALIVED_OPTIONS (code=exited, status=0/SUCCESS)
     Main PID: 116713 (keepalived)
       CGroup: /system.slice/keepalived.service
               ├─116713 /usr/sbin/keepalived -D
               ├─116714 /usr/sbin/keepalived -D
               └─116715 /usr/sbin/keepalived -D
    
    Feb 28 15:42:55 wyl2 Keepalived_vrrp[116715]: Registering gratuitous ARP shared channel
    Feb 28 15:42:55 wyl2 Keepalived_vrrp[116715]: Opening file '/etc/keepalived/keepalived.conf'.
    Feb 28 15:42:55 wyl2 Keepalived_vrrp[116715]: WARNING - default user 'keepalived_script' for script e...ate.
    Feb 28 15:43:00 wyl2 Keepalived_vrrp[116715]: WARNING - script `killall` resolved by path search to `...ath.
    Feb 28 15:43:00 wyl2 Keepalived_vrrp[116715]: SECURITY VIOLATION - scripts are being executed but scr...led.
    Feb 28 15:43:00 wyl2 Keepalived_vrrp[116715]: VRRP_Instance(VI_1) removing protocol VIPs.
    Feb 28 15:43:00 wyl2 Keepalived_vrrp[116715]: Using LinkWatch kernel netlink reflector...
    Feb 28 15:43:00 wyl2 Keepalived_vrrp[116715]: VRRP_Instance(VI_1) Entering BACKUP STATE
    Feb 28 15:43:00 wyl2 Keepalived_vrrp[116715]: VRRP sockpool: [ifindex(2), proto(112), unicast(0), fd(10,11)]
    Feb 28 15:43:00 wyl2 Keepalived_vrrp[116715]: VRRP_Script(check_nginx_alived) succeeded
    Hint: Some lines were ellipsized, use -l to show in full.

启动后，我们查看vip的绑定情况，是在128的机器上

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d5bDk1Mjc_size_16_color_FFFFFF_t_70 2][]

在浏览器上输入虚ip进行访问

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d5bDk1Mjc_size_16_color_FFFFFF_t_70 3][]

### 3 高可用验证 ###

停止128上的nginx服务

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d5bDk1Mjc_size_16_color_FFFFFF_t_70 4][]

发现vip已经飘到129的机器上了。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d5bDk1Mjc_size_16_color_FFFFFF_t_70 5][]

再次在浏览器上验证

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d5bDk1Mjc_size_16_color_FFFFFF_t_70 6][]

可以看到服务依然是可用的。生产环境我们只要把两个nginx配置一样的情况即可。

注意：如果nginx用到本地文件，则还需要注意要做存储的高可用。如glusterfs，nfs等。否则会找本地文件，找不到的。

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