【Nginx】Nginx-keepalived + Nginx 实现高可用集群

红太狼 2023-02-17 14:51 36阅读 0赞

## Keepalived + Nginx 高可用集群 (主从模式) ##

### 集群架构图 ###

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NTgxMjgy_size_16_color_FFFFFF_t_70_pic_center]

### 搭建 ###

#### 所需环境 ####

<table> 
 <thead> 
  <tr> 
   <th>HOSTNAME</th> 
   <th>IP</th> 
   <th>说明</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>LB-01</td> 
   <td>192.168.145.135</td> 
   <td>Keepalived 主服务器（Nginx 主负载均衡器）</td> 
  </tr> 
  <tr> 
   <td>LB-02</td> 
   <td>192.168.145.136</td> 
   <td>Keepalived 备服务器（Nginx 备负载均衡器）</td> 
  </tr> 
  <tr> 
   <td>WEB-01</td> 
   <td>192.168.145.137</td> 
   <td>Web 服务器节点1</td> 
  </tr> 
  <tr> 
   <td>WEB-02</td> 
   <td>192.168.145.138</td> 
   <td>Web 服务器节点2</td> 
  </tr> 
 </tbody> 
</table>

#### 安装 Nginx ####

在 LB-01，LB-02 分别安装 Nginx

[Linux 安装 Nginx][Linux _ Nginx]

#### 安装 Tomcat ####

在 WEB01, WEB02 分别安装 Tomcat

[Linux 安装 Tomcat][Linux _ Tomcat]

#### 配置 Nginx LB-01 ####

upstream backserver {
        server 192.168.145.137:8080;
        server 192.168.145.138:8080;
     }
      server {
          listen       80;
          server_name  LB-01;
          location / {
          proxy_pass http://backserver;
          }
      }

#### 配置 Nginx LB-02 ####

upstream backserver {
        server 192.168.145.137:8080;
        server 192.168.145.138:8080;
     }
      server {
          listen       80;
          server_name  LB-02;
          location / {
          proxy_pass http://backserver;
          }
      }

#### 安装 Keepalived ####

在两台 Nginx 服务器都安装 Keepalived

yum install keepalived -y

#### 配置主 keepalived ####

配置文件在 `/etc/keepalived`

! 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 192.168.145.135
       smtp_connect_timeout 30
       router_id LVS_DEVEL # 通过这个名字能访问到主机，需要修改 /etc/hosts 文件添加 127.0.0.1 LVS_DEVEL
    }
    
    vrrp_script chk_http_port {
    
        script "/usr/local/nginx/nginx_check.sh" # 脚本文件位置,监听 Nginx 状态
    
        interval 2              # 检测脚本执行的间隔
    
        weight 2
    
    }
    
    vrrp_instance VI_1 {
        state MASTER            # 备份服务器上将 MASTER 改为 BACKUP
        interface ens33          # 网卡，通过 ifconfig 命令查看网卡名称
        virtual_router_id 51    # 主、备机的 virtual_router_id 须相同
        priority 100            # 主、备机取不同的优先级，主机值较大，备机值较小
        advert_int 1
        authentication {
            auth_type PASS
            auth_pass 1111
        }
        virtual_ipaddress {
            192.168.145.110      # VRRP H 虚拟地址，网段要一致
        }
    }

配置脚本文件，监听 nginx 状态

vi /usr/local/nginx/nginx_check.sh
    #!/bin/bash
    A=`ps -C nginx ¨Cno-header |wc -l`
    if [ $A -eq 0 ];then
        /usr/local/nginx/sbin/nginx
        sleep 2
        if [ `ps -C nginx --no-header |wc -l` -eq 0 ];then
            killall keepalived
        fi
    fi

#### 配置从 Keepalived ####

! 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 192.168.145.142
       smtp_connect_timeout 30
       router_id LVS_DEVEL # 通过这个名字能访问到主机，需要修改 /etc/hosts 文件添加 127.0.0.1 LVS_DEVEL
    }
    
    vrrp_script chk_http_port {
    
            script "/usr/local/nginx/nginx_check.sh" # 脚本文件位置
    
            interval 2                              # 检测脚本执行的间隔
    
            weight 2
    
    }
    
    vrrp_instance VI_1 {
        state BACKUP                        # 备份服务器上将 MASTER 改为 BACKUP
        interface ens33                      # 网卡
        virtual_router_id 51        # 主、备机的 virtual_router_id 须相同
        priority 90                 # 主、备机取不同的优先级，主机值较大，备机值较小
        advert_int 1
        authentication {
            auth_type PASS
            auth_pass 1111
        }
        virtual_ipaddress {
            192.168.145.110          # VRRP H 虚拟地址
        }
    }

配置脚本文件，监听 nginx 状态

#### 启动 Nginx ####

./nginx

#### 启动 Keepalived ####

systemctl start keepalived.service

### 测试 ###

访问配置的虚拟IP：192.168.145.110  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NTgxMjgy_size_16_color_FFFFFF_t_70_pic_center 1]

访问成功，这时关闭主服务器的 nginx 和 keepalived

./nginx -s stop
    systemctl stop keepalived.service

再次访问虚拟IP：192.168.145.110，还是能访问成功  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NTgxMjgy_size_16_color_FFFFFF_t_70_pic_center 2]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NTgxMjgy_size_16_color_FFFFFF_t_70_pic_center]: https://img-blog.csdnimg.cn/20200614170945382.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NTgxMjgy,size_16,color_FFFFFF,t_70#pic_center
[Linux _ Nginx]: https://blog.csdn.net/qq_37581282/article/details/106722535
[Linux _ Tomcat]: https://blog.csdn.net/qq_37581282/article/details/86492346
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[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NTgxMjgy_size_16_color_FFFFFF_t_70_pic_center 2]: https://img-blog.csdnimg.cn/20200614171011325.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NTgxMjgy,size_16,color_FFFFFF,t_70#pic_center