Task Scheduling in Distributed Systems

                         Hesham El-Rewini
                  Department of Computer Science
                 University of Nebraska at Omaha
                       Omaha, NE 68182-0500

The scheduling problem emerges whenever there is a choice as to the order 
in which a number of tasks can be performed, and the assignment of tasks 
to servers for processing. It is considered one of the most challenging
problems in distributed computing. The goal of scheduling is to
determine an assignment of tasks to processing elements in order to
optimize certain performance indices.

This problem is known to be computationally intractable in many
cases. Fast optimal algorithms can only be obtained when some
restrictions are imposed on the models representing the program
and/or the distributed system. 
The intractability of the problem has led to a large number of 
heuristics for solving the general problem. These heuristics do 
not guarantee optimal solutions, but they attempt to find near 
optimal solutions.

In this presentation, the scheduling problem in many of its
variations will be discussed. The major results will be summarized
including algorithms to solve special cases of the problem when
communication among tasks is considered. New directions in solving
the problem will also be discussed.

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Biography
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Hesham El-Rewini is an associate professor of computer science at the
University of Nebraska at Omaha. His research interests include parallel 
and distributed computing, parallel database systems, scheduling 
algorithms. El-Rewini is the coauthor of three books. His most recent 
book "Distributed and parallel Computing" will be available in November 
1997 (Book web site: http://www.manning.com/El-Rewini).
He is serving on the editorial board of IEEE Concurrency and is an 
associate editor of International Journal on Parallel and Distributed 
Systems and Networks. El-Rewini is chairing the Software Track of the 
Hawaii International Conference on System Sciences since 1992.
He received his PhD from Oregon State University in 1990, and 
his BS and MS from the University of Alexandria, Egypt, in 1982 and 1985, 
respectively, all in computer science.
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