DEPARTMENT OF COMPUTER SCIENCE
DOCTORAL DISSERTATION DEFENSE


Candidate: Mehmet Karaul
Advisor: Zvi M. Kedem
Metacomputing and Resource Allocation
on the World Wide Web

1:15 p.m., Thursday, April 23, 1998
12th floor conference room, 719 Broadway



Abstract

The World Wide Web is a challenging environment for distributed computing due to its sheer size and the heterogeneity and unreliability of machines and networks. Therefore, scalability, load balancing, and fault masking play an important role for Web-based systems. In this dissertation, I present novel mechanisms for resource allocation and parallel computing on the Web addressing these issues.

Large Web sites rely on a set of geographically dispersed replicated servers among which client requests should be appropriately allocated. I present a scalable decentralized design, which pushes the allocation functionality onto the clients. At its core lies a pricing strategy that provides incentives to clients to control the dispatching of requests while still allowing clients to take advantage of geographic proximity. An adaptive algorithm updates prices to deal with dynamic changes. A prototype system based on this architecture has been implemented and its functionality validated through a series of experiments.

Parallel computing on local area networks is based on a variety of mechanisms targeting the properties of this environment. However, these mechanisms do not effectively extend to wide area networks due to issues such as heterogeneity, security, and administrative boundaries. I present a prototype system which allows application programmers to write parallel programs in Java and allows Java-capable browsers to execute parallel tasks. It comprises a virtual machine model which isolates the program from the execution environment, and a runtime system realizing this machine on the Web. Load balancing and fault masking are transparently provided by the runtime system.