Vijay Tewari

A Framework for Classifying Peer-to-Peer Technologies

Popularized by Napster and Gnutella file sharing solutions, peer-to-peer (P2P) computing has suddenly emerged at the forefront of Internet computing. The basic notion of cooperative computing and resource sharing has been around for quite some time, although these new applications have opened up possibilities of very flexible web-based information sharing. This article provides a frame-work for classifying current and future P2P technologies. The main motivation for the classification is to identify basic characteristics of P2P applications so that the infrastructure to support P2P computing can concentrate on these basic characteristics.

Overload Control Mechanisms for Web Servers

Web servers often experience overload situations due to the extremely bursty nature of Internet traffic, popular online events or malicious attacks. Such overload situations significantly affect performance and may result in lost revenue as reported by the recent denial of service attacks. Overload control schemes are well researched and understood in telecommunication systems. However, their use in web servers is currently very limited. Our focus in this paper is to propose effective overload control mechanisms for web servers. An important aspect in overload control is to minimize the work spent on a request which is eventually not serviced due to overload. This paper studies three simple schemes for controlling the load effectively. The first scheme selectively drops incoming requests as they arrive at the server using an intelligent network interface card (NIC). The second scheme provides feedback to a previous node (proxy server or ultimate client) to allow a gapping control that reduces offered load under overload. The third scheme is simply a combination of the two. The experimental results show that even these simple schemes are effective in improving the throughput of the web server by 40% and response time by 70% under heavy overloads, as compared with the case without any overload control.

Geist: a generator for e-commerce & internet server traffic

This paper describes Geist, a traffic generator for stress testing of web servers. The generator provides a large number of dialable parameters that allow traffic characteristics to range from simple static web-page browsing to the transactional traffic seen by e-commerce front end servers. Unlike other traffic generators, our generator concentrates on the characteristics of the aggregate traffic arriving at the server, which allows for better control of the scaling properties of the traffic and a more scalable generation. In this paper, we describe the traffic characterization and generation process that Geist is based on. We also present the performance of our current implementation, instances of its usage and directions for future work.

Geist: A Web Traffic Generation Tool

This paper briefly describes the design of Geist, a traffic generator for stress testing of web/e-commerce servers. The generator provides a large number of dialable parameters that allow traffic characteristics to range from simple static web-page browsing to the transactional traffic seen by e-commerce front end servers. Unlike other traffic generators, Geist concentrates on the characteristics of the aggregate traffic arriving at the server, which allows for realistic traffic generation without any explicit modeling of users or network components.

Design and networking considerations for FACE

As we step into the twenty first century, we are surrounded by technology wearing its way into our day-to-day life. making every aspect of it more convenient and organized. Yet, in every household there is one front, i.e. the process of cooking, which has not been sufficiently automated. Even in a commercial environment (restaurant kitchens), the process of cooking remains largely manual. We investigate the potential for a fully automated cooking environment (FACE). We start by describing the architecture of FACE and present an overview of its components and their functionality. Then, we explore communication considerations between various FACE components and discuss existing solutions for addressing the basic networking needs. We also provide a detailed example to describe the workflow in FACE and help illustrate the communication requirements between FACE components. Ultimately, our aim is to provide the vision for a flexible, highly integrated and fully coordinated cooking environment.