nginx高可用keepalived--02--（Linux运维26）

最新推荐文章于 2023-08-13 16:43:49 发布

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最新推荐文章于 2023-08-13 16:43:49 发布

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分类专栏： linux运维文章标签： nginx linux 运维

本文链接：https://blog.youkuaiyun.com/ncnhhm/article/details/120396657

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nginx+keepalived高可用

1. 高可用出现脑裂问题
2.高可用集群的双主配置
- 2.2 编写nginx的配置文件（解决192.168.246.5 192.168.246.6也可以访问www.yq.com与bbs.yq.com）
- 2.3 测试

1. 高可用出现脑裂问题

脑裂问题：高可用备服务器接收不到主服务器发送的组播包,备服务器上会自动生成VIP地址
原因：
1.集群之间的通讯问题
2.安全策略的阻止（防火墙）

解决：
主服务器：进行监控，发出信息提醒
备服务器：主服务器出现故障，或出现脑裂问题

1.2模拟问题

关闭主的keepalived服务

systemctl stop keepalived

1.2.1 编写监控脚本

 #!/bin/bash
num=`ps -ef|grep -c [n]ginx`
if [ $num -lt 2 ]
then
   systemctl stop keepalived
fi

实时监控keepalived

vim /etc/keepalived/keepalived.conf

  vrrp_script check_web {
       script "/server/scripts/check_web.sh"   --- 定义需要监控脚本(脚本是执行权限)   
       interval 2                              --- 执行脚本的间隔时间(秒)  
       weight 2                                --- ???
    }
    $check_web
    track_script {                             
         check_web                             --- 调用执行你的脚本信息
    }

所以最后：

 ! Configuration File for keepalived
     global_defs {
       router_id lb01
    }
    
    vrrp_script check_web {
     script "/server/scripts/check_web.sh"  
     interval 3   
     weight 2
    }
    
    vrrp_instance oldboy {
        state MASTER
        interface eth0
        virtual_router_id 51
        priority 150
        advert_int 1
        authentication {
            auth_type PASS
            auth_pass 1111
        }
        virtual_ipaddress {
         192.168.246.3/24
        }
       track_script {
             check_web
       }
    }

1.3 演示：

关闭lb01的nginx

systemctl stop nginx

systemctl status keepalived

● keepalived.service - LVS and VRRP High Availability Monitor
   Loaded: loaded (/usr/lib/systemd/system/keepalived.service; enabled; vendor preset: disabled)
   Active: inactive (dead) since Mon 2021-09-20 22:56:02 CST; 9s ago
  Process: 6270 ExecStart=/usr/sbin/keepalived $KEEPALIVED_OPTIONS (code=exited, status=0/SUCCESS)
 Main PID: 6272 (code=exited, status=0/SUCCESS)
   CGroup: /system.slice/keepalived.service

Sep 20 22:55:25 lb01 Keepalived_vrrp[6274]: VRRP_Instance(oldboy) Sending/queueing gratuitous ARPs on eth0 for...246.3
Sep 20 22:55:25 lb01 Keepalived_vrrp[6274]: Sending gratuitous ARP on eth0 for 192.168.246.3
Sep 20 22:55:25 lb01 Keepalived_vrrp[6274]: Sending gratuitous ARP on eth0 for 192.168.246.3
Sep 20 22:55:25 lb01 Keepalived_vrrp[6274]: Sending gratuitous ARP on eth0 for 192.168.246.3
Sep 20 22:55:25 lb01 Keepalived_vrrp[6274]: Sending gratuitous ARP on eth0 for 192.168.246.3
Sep 20 22:56:01 lb01 Keepalived[6272]: Stopping
Sep 20 22:56:01 lb01 systemd[1]: Stopping LVS and VRRP High Availability Monitor...
Sep 20 22:56:01 lb01 Keepalived_vrrp[6274]: VRRP_Instance(oldboy) sent 0 priority
Sep 20 22:56:01 lb01 Keepalived_vrrp[6274]: VRRP_Instance(oldboy) removing protocol VIPs.
Sep 20 22:56:02 lb01 systemd[1]: Stopped LVS and VRRP High Availability Monitor.
Hint: Some lines were ellipsized, use -l to show in full.

此时lb01

ip a

eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN group default qlen 1000
    link/ether 00:0c:29:61:5f:bb brd ff:ff:ff:ff:ff:ff
    inet 192.168.246.5/24 brd 192.168.246.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe61:5fbb/64 scope link 
       valid_lft forever preferred_lft forever

lb02:

ip a

eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN group default qlen 1000
    link/ether 00:0c:29:36:60:a7 brd ff:ff:ff:ff:ff:ff
    inet 192.168.246.6/24 brd 192.168.246.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet 192.168.246.3/24 scope global secondary eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe36:60a7/64 scope link 
       valid_lft forever preferred_lft forever

1.4 恢复

lb01:

systemctl start nginx
systemctl start keepalived

ip a

eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN group default qlen 1000
    link/ether 00:0c:29:61:5f:bb brd ff:ff:ff:ff:ff:ff
    inet 192.168.246.5/24 brd 192.168.246.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet 192.168.246.3/24 scope global secondary eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe61:5fbb/64 scope link 
       valid_lft forever preferred_lft forever

2.高可用集群的双主配置

配置文件：
lb01

vim /etc/keepalived/keepalived.conf

  ! Configuration File for keepalived
     global_defs {
       router_id lb01
    }   
    vrrp_instance yq {
        state MASTER
        interface eth0
        virtual_router_id 51
        priority 150
        advert_int 1
        authentication {
            auth_type PASS
            auth_pass 1111
        }
        virtual_ipaddress {
         192.168.246.3/24
        }
    }
    vrrp_instance cn{
        state BACKUP
        interface eth0
        virtual_router_id 52
        priority 100
        advert_int 1
        authentication {
            auth_type PASS
            auth_pass 1111
        }
        virtual_ipaddress {
         192.168.246.4/24
        }
    }

lb02:

! Configuration File for keepalived
    global_defs {
       router_id lb02
    }
    
    vrrp_instance yq{
        state BACKUP
        interface eth0
        virtual_router_id 51
        priority 100
        advert_int 1
        authentication {
            auth_type PASS
            auth_pass 1111
        }
        virtual_ipaddress {
            192.168.246.3/24
        }
    }
    vrrp_instance cn{
        state MASTER
        interface eth0
        virtual_router_id 52
        priority 150
        advert_int 1
        authentication {
            auth_type PASS
            auth_pass 1111
        }
        virtual_ipaddress {
            192.168.246.4/24
        }
    }

2.2 编写nginx的配置文件（解决192.168.246.5 192.168.246.6也可以访问www.yq.com与bbs.yq.com）

添加ip+端口的监听方式，在使用web集群的内网ip
外网ip的配置

upstream yq{
       server 192.168.246.7:80;
       server 192.168.246.8:80;
       server 192.168.246.9:80;
    }
    server {
        listen       192.168.246.3:80;
        server_name  www.yq.com;
        location / {
           proxy_pass http://yq;
           proxy_set_header Host $host;
           proxy_set_header X-Forwarded-For $remote_addr;
           proxy_next_upstream error timeout http_404 http_502 http_403;
        }
    }
    server {
        listen       192.168.246.4:80;
        server_name  bbs.yq.com;
        location / {
           proxy_pass http://yq;
           proxy_set_header Host $host;
           proxy_set_header X-Forwarded-For $remote_addr;
        }
    }

内网ip配置：这个需要你的web集群不可以访问外网

upstream yq{
       server 172.16.1.7:80;
       server 172.16.1.8:80;
       server 172.16.1.9:80;
    }
    server {
        listen       192.168.246.3:80;
        server_name  www.yq.com;
        location / {
           proxy_pass http://yq;
           proxy_set_header Host $host;
           proxy_set_header X-Forwarded-For $remote_addr;
           proxy_next_upstream error timeout http_404 http_502 http_403;
        }
    }
    server {
        listen       192.168.246.4:80;
        server_name  bbs.yq.com;
        location / {
           proxy_pass http://yq;
           proxy_set_header Host $host;
           proxy_set_header X-Forwarded-For $remote_addr;
        }
    }

这样配置会出问题，因为192.168.246.3 192.168.246.4 是虚拟存在的网卡，再配指文件中，主机会找不到，所以启动报错：
解决办法：

echo 'net.ipv4.ip_nonlocal_bind = 1' >>/etc/sysctl.conf
sysctl -p

systemctl reload nginx

2.3 测试

配置windows的hosts

192.168.246.3 wwww.yq.com 
192.168.246.4 bbs.yq.com

访问：

 wwww.yq.com 
 bbs.yq.com

curl -H host:www.yq.com 192.168.246.3
curl -H host:bbs.yq.com 192.168.246.4