[Colloq] **Hiring Talk** Wed. April 17 ***11:30am*** 149CN

[Rachel Bates]

College of Computer Science Colloquium

presents
Alexandros Labrinidis
Department of Computer Science
University of Maryland

who will speak on:
WebView Materialization for Scalable Web Servers

Wednesday, April 17, 2002
11:30am
149 Cullinane Hall
Northeastern University



ABSTRACT

The frustration of broken links from the early Web has been replaced today
by the frustration of web servers stalling or crashing under the heavy load
of dynamically generated content. Even seemingly static web pages are
usually   generated dynamically in order to include personalization and
advertising features.  Such dynamic content has high resource demands and
poses a scalability problem for both web and database servers.

In my work, I have used view materialization techniques to ameliorate this
scalability   problem.  I introduced WebViews to identify frequently
accessed web page fragments, which are dynamically generated.   With
materialization, these   WebViews   are constantly refreshed in the
background in anticipation of future requests.

WebView materialization drastically improves Quality of Service (QoS), but
poses new challenges: (1) the selection of WebViews to materialize has to be
performed in real-time, with limited knowledge of the access and update
patterns, and must adapt rapidly to changing web workloads, (2) the Quality
of Data served  (QoD) must be considered during the selection process, and,
(3) scheduling the updates in the background concurrently with user requests
has a significant impact on the QoD.

In this talk, I will describe how to bridge the gap between QoS and QoD in
scalable, database-driven internet servers.  I will present success stories
for WebView Materialization, describe an adaptive Online   algorithm for
WebView selection, and   focus on the update scheduling problem: determine
the order to refresh WebViews so that the overall QoD is maximized.

Host:
Betty Salzberg