What is Linux Virtual Private Server ?
Due to the wide growth of the Internet, the workload on the servers providing Web, email, and media services has increased widely.More and more websites are being developed to keep up with the growing demands and are employing many techniques to avoid overloading their web servers. Building a scalable server on a cluster of computers is one of the solutions that is being effectively used. With such a cluster technology, the increasing requests can be easily managed by simply adding one or more new servers to the existing cluster as required. In this article we will look forward at setting up one such scalable, network load-balancing server cluster using a Virtual Private Server via Linux Virtual Private Server Project.
The advantage of using Linux Virtual Private Server Project is that unlike Microsoft network load-balancing clusters, the Linux Virtual Private Server Project enables you to add a node running any OS which supports TCP/IP to the cluster.
The cluster setup consists of a load balance server — also known as the Virtual Private Server — running on the Linux OS and one or more real servers connected to it through a hub or a switch. The real servers — which can run on any OS — provide network services to the web clients, whereas the Virtual Private Server does IP-level load balancing of the incoming traffic to the various real servers. This Linux virtual Private server acts as an interface between the users and the real servers and, therefore, makes the parallel services of the real servers to appear as a virtual service on a one single IP address.
When the virtual server receives a client request for data, than it transfers the request to the appropriate real server according to a scheduled algorithm. The real server then replies to the Private Server, which in turn forwards the reply to the client. Although it is actually the real server that services the client request, to the client it appears as if the response came from the virtual Private Server. The IP address of the real server is masqueraded by the IP address of the virtual server.This virtual server uses 2 network interfaces, one connected to the Internet for the clients to access and the other connected to the internal local area network (LAN), where all the real servers are placed. Scalability is achieved by transparently adding or removing real servers from the internal LAN.
