EVALUATION OF LOAD BALANCING ALGORITHMS AND INTERNET TRAFFIC MODELING FOR PERFORMANCE ANALYSIS

C H A P T E R  ONE

INTRODUCTION

This research is on Load Balancing and Internet traffic modeling are presented in this thesis.

Load Balancing is a form of system performance evaluation, analysis and optimization, which attempts to distribute a number of logical processes across a network of processing elements. There have been many algorithms and techniques that have been developed and studied for improving system performance. In early research in the field of

computer science, the main focus for improving performance was to develop algorithms and techniques to optimize the use of systems with limited and expensive resources for scientific computing and information systems. Later, there was an emphasis on how to network groups of computers or workstations and then share the resources among workgroups.

More recently there has been a tremendous increase in the popularity of the Internet as a system for sharing and gathering information. The use of the Internet has been increasing at a tremendous rate and there always has been a concern among those in the Internet community that enough resources will be available to provide the expected quality of service that is received by its users.

The process of balancing, sharing, scheduling or distributing work using a network of computers or a system of multiple processing elements is a widely studied subject. This paper will focus on recent works that have been written regarding todays computing environments.

In this thesis, we will look at the art of load balancing and how it can be applied to distributed networks and more specifically the Internet. Initially, the focus of the research for this thesis was on development and analysis of algorithms that minimized the amount of messaging or probing that is required for determining the current workload of a set of processing elements, such as a group of replicated web servers. These algorithms were to compare stochastic based methods of estimating server workloads, with more intrusive methods of messaging and probing. During the process of developing the simulator to be used for evaluating the algorithms in this study, tasks related to modeling network workloads, and the workloads related to the Internet in particular, were identified to be crucial to the research in this area and as a result of this effort, network modeling has become a significant portion of this thesis.

The thesis is divided into the following chapters. Chapter 2 will discuss the concepts and research related to the subject of Load Balancing. Chapter 3 will discuss the issues related to modeling network traffic and in particular Internet traffic. Chapter 4 describes the Network Simulator used to evaluate the load balancing algorithms. Chapter 5 is the Experimental Design of the network simulations, and Chapter 6 will discuss the results of the experimental simulations. Finally, Chapter 7 will discuss the conclusions based upon the experiments performed in this study.

Finally, in addition to the goals already mentioned, it is the hope of the author that this research can be used as a reference for the continued study in the areas of network performance evaluation, modeling and simulation.