2006-2007 Seminar Series

A common requirement of many Internet services is to send the same data to a number of hosts at the same time. Without IP-level multicast, this form of group communication is realized by unicasting the data to each desired host. Although this approach is portable and easy to implement, it is extremely inefficient for the sending host. This makes it difficult to scale game and streaming media servers to large numbers of clients. In the first part of this talk we describe a kernel-based technique to efficiently facilitate unicast send operations for group communication.

In the second part of this talk we describe preliminary work being done to support the in-kernel execution of user code. We explain why we expect this approach to reduce overheads due to context switches and data copying and as a result improve the scalability and performance of services that forward unmodified or transcoded data.

This is joint work with Martin Karsten, Jialin Song, Michael Kwok, Elad Lahav and Weihan Wang.

Tim Brecht is currently an Associate Professor in the David R. Cheriton School of Computer Science at the University of Waterloo. He has previously held positions as an Associate Professor at York University, a Visiting Scientist at IBM's Center for Advanced Studies, and a Research Scientist with Hewlett Packard Labs. Current research interests include: Internet Systems, Services and Applications; Operating Systems; Parallel and Distributed Systems; and Performance Evaluation. Tim obtained his B.Sc. from the University of Saskatchewan in 1983, MMath from the University of Waterloo in 1985, and Ph.D. from the University of Toronto in 1994.