Metacomputing and Resource Allocation on the World Wide Web

摘要

Load balancing, fault-tolerance, and scalability play an important role in distributed computing. They are of interest for many distributed systems problems as well as for many problems in other areas. Collaborative applications, for example, need to provide some level of fault tolerance to allow for failures of participants' machines. In networking, as another example, techniques are needed to balance the load offered to network links and to tolerate machine failures. In this dissertation, the author presents three projects with different goals to which all or some of these issues are relevant, and presents different ways to address them. The main focus will be on the World Wide Web, but the techniques presented here are not restricted to it. The Web can be viewed as a large, unreliable, distributed platform composed of different machines with different speeds that may slow down, speed up, and crash-fail at any time, and networks with different capacities that may get congested and partitioned. All of these factors make the Web a very challenging environment. The projects the author presents range from resource allocation, to parallel computing, to infrastructure support for collaborative applications. The dissertation is organized as follows: first the author presents WebSeAl and discusses how it addresses scalability, load balancing, and fault masking in Chapter 2. In Chapter 3, he will describe Charlotte and the techniques it uses to deal with machines of different speeds and crash- failed machines. In Chapter 4, he presents an infrastructure Web-based application which contains various aspects relating to scalability and fault masking.