'XR’ (Crossroads) Load Balancer for Web Servers on RHEL/CentOS

Crossroads is a service independent, open source load balance and fail-over utility for Linux and TCP based services. It can be used for HTTP, HTTPS, SSH, SMTP and DNS etc. It is also a multi-threaded utility which consumes only one memory space which leads to increase the performance when balancing load.

Let’s have a look at how XR works. We can locate XR between network clients and a nest of servers which dispatches client requests to the servers balancing the load.

If a server is down, XR forwards next client request to the next server in line, so client feels no down time. Have a look at the below diagram to understand what kind of a situation we are going to handle with XR.

There are two web-servers, one gateway server which we install and setup XR to receive client requests and distribute them among the servers.

XR Crossroads Gateway Server : 172.16.1.204
Web Server 01 : 172.16.1.222

Web Server 02 : 192.168.1.161

In above scenario, my gateway server (i.e XR Crossroads) bears the IP address 192.168.2.55, webserver01 is 192.168.2.155 and it listens through port 8888 and webserver02 is 192.168.1.161 and it listens through port 555.

Now all I need is to balance the load of all the requests that receives by the XR gateway from internet and distribute them among two web-servers balancing the load.