International Journal of Computer Applications (0975 – 8887) Volume 95– No.18, June 2014 38 Back-End Forwarding Scheme in Server Load Balancing using Client Virtualization Shreyansh Kumar School of Computing Science and Engineering VIT University Chennai Campus Parvathi.R, Ph.D Associate Professor- School of Computing Science and Engineering VIT University Chennai Campus ABSTRACT Load balancing can be done at two levels, the HTTP level and the network level. It refers to the distribution of the HTTP request made by the user across the web server in a server cluster and is achieved by various algorithms such as Random Selection, Round Robin, weighted Round Robin etc. At the network level load balancers are used for the purpose of balancing the load. The approach such as DNS forwarding and spraying the load across the servers is very useful and effective at the network level [11][12]. The load balancers receives the request and proxies the destination ip for forwarding the request to the less utilized servers in order to gain better performance. This paper proposes a server load balancing scheme mainly for the webservers by making the limited number of clients to work as a virtual server which are called virtual clients in the webserver network. This approach is done at the HTTP level by forwarding the HTTP request to the nearest and less loaded virtual client. The HTTP request is only forwarded to get the static content in order to save the current bandwidth utilization of the web server and process more dynamic request on the server side. The daemon routine controls the whole process of web server load balancing but it only processes the HTTP requests. The daemon routine only resides on the web server backend. The client virtualization provides a new anti-overloading technique to reduce the access time of the server and to utilize the server resources without any additional cost. The Client Virtualization also provides a better way to utilize the system bandwidth in web server network. General Terms Web-Server, HTTP, URL Keywords Virtual Clients, dynamic load balancing, daemon routine(process) 1. INTRODUCTION Since the deployment of the World Wide Web (WWW) servers the growth of internet user has vastly increased. In the era of rapid developing internet technologies always a huge number of internet users are expected across the globe. To satisfy the needs of the internet users there is a need to serve them according to their requests. The term internet user is called as client. The WWW webserver should provide high quality service [5]. When the client request for a particular resource then the requests has to be serviced so, for servicing these clients we need a Web server. Since, the amount of internet users is quite large a webserver has to process large number of requests thus, at times resulting in overloading the webserver. To process the large number of requests from the clients the web server easily gets overload thus, it’s better to migrate [10] (distribute) the load on other available servers too. The server load also has to be distributed so as not to overload the other available servers in the web-server network. The network congestion in system can reason the overloading which prompts break-down of servers. The best possible appropriation of load on the server is carried out by the load balancer. The load balancer is answerable for the equally assigning the requests to the server pool in order to disallow the over-loading of the single server in the web- server system. The load balancing techniques could be exceptionally adequate for the server hubs to process the client’s demands. The load balancing strategies helps in minimizing the reaction time and to legitimately use the throughput of the server network. A large number of algorithms are being utilized by the load balancers to verify which server to send the request to. Random choice, round robin, saturation load balancing, load based, least connection and failover load balancing are the algorithms which are being very frequently used by the load balancers to distribute the load. To enhance the load adjust around the servers various parameters, for example server's recent load, recent reaction time and how much traffic it has been recently assigned are taken into account. 2. RELATED WORK The correspondence between the web client and a web server is two layered architecture. The architecture is characterized by the client that shows the information content and web server that transfer information to the client. A web server is a procedure which runs on a framework which accepts the HTTP requests from the clients over the web server system and is equipped for transforming the solicitation with the asked for a particular web document. The remote clients can connect to the web server through their web browser by clicking the valid web address in the URL field and the request is forwarded to the DNS server then the DNS server forwards the request to the actual mapped server [3][4][7].The web server gets truly extensive number of HTTP requests from the clients for the requested web content, after appropriating the client's demands the web server delivers the response for the web content which comprises of both the static and the dynamic part. Provided that a web server appropriates an immense demand it will make diverse threads for every client and the servers request and response handling. This thread creation for every client may require some serious time from the webserver to serve the number of HTTP requests from the client. The general network level load balancing architecture with DNS forwarding is shown in the Figure1. This DNS