NGINX - Load Balancing Web Servers.

Setting up NGINX for HTTP load balancing.

Nginx server is running as below.

nginx-server : nginx.server.com //nginx

Below are the 3 server which run a web application which needs to be load balanced.

Server1 : node1.application.com //web_server

Server2 : node2.application.com //web_server

Server3 : node3.application.com //web_server

Install NGINX on RHEL/Centos6

Step 1 : Create a Repo. in [vim /etc/yum.repos.d/nginx.repo]

CENTOS6

[nginx]

name=nginx repo

baseurl=http://nginx.org/packages/centos/$releasever/$basearch/

gpgcheck=0

enabled=1

RHEL:

[nginx]

name=nginx repo

baseurl=http://nginx.org/packages/rhel/$releasever/$basearch/

gpgcheck=0

enabled=1

Step 2 : Installation 

[ahmed@ngnix ~]$ sudo yum install nginx

Step 3 : Configuration: sudo vim /etc/nginx/nginx.conf

#------BEGIN CONFIG------------

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;

    #tcp_nopush     on;

    keepalive_timeout  65;

    #gzip  on;

    #include /etc/nginx/conf.d/*.conf;

    

    upstream myappredirect 

    {

        server node1.application.com;

        server node2.application.com;

        server node3.application.com;

    }

    server 

    {

    listen 80;

        location / {

            proxy_pass http://myappredirect;

        }    

    }

}

#------END CONFIG-----------

Now we are ready for testing.

[ahmed@ngnix ~]$ sudo service nginx start

Now we can go the browser and hit the IP address of nginx server.

As per the current setup (Default) it will do a Round-Robin to send request to the servers.

"All inbound request to NGINX[nginx.server.com]" -> NGINX will load_balance and distribute traffic to Servers.

-->[NGINX]---->[HOST1]

  \-->[HOST2]

  \-->[HOST3]

Useful Links:

http://nginx.com/resources/admin-guide/load-balancer/#overview

http://nginx.org/en/docs/http/load_balancing.html

http://wiki.nginx.org/Install