Setting Up Nginx and Keepalived High‑Availability on Multiple Servers

The environment consists of four servers: 192.168.210.85 (Nginx primary/Keepalived master), 192.168.210.177 (Nginx secondary/Keepalived backup), and two backend servers 192.168.210.176 and 192.168.210.195.

Nginx installation is performed on all four machines. The main Nginx configuration (/etc/nginx/nginx.conf) is as follows:

user  nginx;
worker_processes  1;
error_log  /var/log/nginx/error.log warn;
pid   /var/run/nginx.pid;

events {
    worker_connections  1024;
}

http {
    include   /etc/nginx/mime.types;
    default_type  application/octet-stream;
    log_format main '$remote_addr- $remote_user [$time_local] "$request"''$status $body_bytes_sent "$http_referer" "$http_user_agent" "$http_x_forwarded_for"';
    access_log  /var/log/nginx/access.log  main;
    sendfile    on;
    keepalive_timeout  65;
    include /etc/nginx/conf.d/*.conf;

    upstream back {
        server 192.168.210.176:80;
        server 192.168.210.195:80;
    }

    server {
        listen 80;
        server_name www.sfqd.com;
        location / {
            proxy_pass http://back;
            proxy_set_header Host $host:$proxy_port;
            proxy_set_header X-Forwarded-For $remote_addr;
        }
    }
}

After editing, Nginx is started on each host.

Keepalived installation follows, with the service started via systemctl start keepalived and its status checked with systemctl status keepalived. The configuration file (/etc/keepalived/keepalived.conf) on the master (192.168.210.85) looks like:

! Configuration File for keepalived
global_defs {
    notification_email {
        [email protected]
    }
}

vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 51
    priority 200
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.210.11
    }
}

The backup node (192.168.210.177) uses a similar file with state BACKUP and a lower priority (150):

! Configuration File for keepalived
global_defs {
    notification_email {
        [email protected]
    }
}

vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    virtual_router_id 51
    priority 150
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.210.11
    }
}

Both nodes are started with systemctl start keepalived. The virtual IP (VIP) 192.168.210.11 should be present on the master; after stopping Keepalived on the master ( systemctl stop keepalived), the VIP migrates to the backup node, confirming failover works.

On the client machine, add an entry to /etc/hosts mapping 192.168.210.11 www.sfqd.com. Accessing http://www.sfqd.com in a browser now routes traffic through Nginx, which load‑balances between the two backend servers. The test confirms that the VIP moves without interruption, completing the Keepalived + Nginx high‑availability setup.