[Colloq] **HIRING TALK** Monday April 1, 11AM in 149 CN

[Rachel Bates]

Monday, April 1, 2002
149 Cullinane Hall
11:00am-12:00pm
host: Paul Attie



Roger Khazan

will talk on:

A Novel Algorithm for Group Communication in Wide-Area Networks.
		  High-quality design and analysis.

ABSTRACT:

Group communication is a powerful paradigm for building fault-tolerant
distributed applications that require both consistency and performance
(e.g., collaborative computing applications, such as military command
and control). However, existing group communication systems were
designed for local-area networks, and as such are inappropriate for
wide-area networks (WANs). They do not perform well, and they do not
scale well.

In this talk I will present a solution to this problem. Specifically,
I will describe a new design of a WAN-oriented group communication
service, and a novel algorithm for implementing "Virtual Synchrony" --
the core semantics of group communication. The algorithm is more
appropriate for WANs than the existing solutions because it involves
fewer rounds of communication and operates in a scalable WAN-oriented
architecture.

The design provides theoretical underpinnings for the Xpand GCS for
Wide-Area Networks, subsequently developed by a joint team at MIT and
the Hebrew University of Jerusalem. The design is carried out formally
and rigorously. It includes formal and precise specifications,
algorithms, correctness proofs, and performance analyses.

Time permitting, I will also mention a new modeling methodology that
assisted in the design and verification of the algorithm, and a new
compositional approach to performance analysis.


--

This talk is based on my PhD dissertation. The main part of the talk
is based on joint work with Idit Keidar. The talk also includes
material co-authored with Idit Keidar, Nancy Lynch, and Alex Shvartsman.