 |
|
|
We measure server throughput as
a number of successfully completed sessions. Using a simulation
model, we show that an overloaded web server can experience a severe
loss of throughput measured as a number of completed sessions
comparing against the server throughput measured in requests per
second. Moreover, statistical analysis of completed sessions reveals
that the overloaded web server discriminates against longer sessions.
For e-commerce retail sites, longer sessions are typically the ones
that would result in purchases.
We introduce a session based admission control (SBAC) to prevent
a web server from becoming overloaded and to ensure that longer
sessions can be completed.
We show that a web server augmented with the admission control
mechanism is able to provide a fair guarantee of completion, for any
accepted session, independent of a session length. This provides a
predictable and controllable platform for web applications, and is a
critical requirement for any e-business.
We propose two new admission control strategies: hybrid
and predictive, aiming to optimize the performance of SBAC
mechanism.
Related Papers and Reports
- L. Cherkasova, P. Phaal: Session
Based Admission Control: a Mechanism for Peak Load Management
of Commercial Web Sites. IEEE J. Transactions on Computers, Vol. 51,
No. 6, June 2002.
- L. Cherkasova, P. Phaal:
Predictive Admission Control Strategy
for Overloaded Commercial Web Server.
In Proceedings of the Eighth International Symposium on
Modeling, Analysis and Simulation of Computer and Telecommunication
Systems (MASCOTS'2000).
- L. Cherkasova, P. Phaal: Session Based Admission Control:
a Mechanism for Improving Performance of Commercial Web Sites.
postscript or pdf
In Proceedings of Seventh International Workshop on Quality
of Service, IEEE/IFIP event, London, May 31-June 4, 1999.
- L. Cherkasova, P. Phaal: Session Based Admission Control:
a Mechanism for Web QoS.
postscript or pdf
In Poster Proceedings of WWW8 - Eighth International World Wide Web Conference, Toronto, Canada, May, 1999.
- L. Cherkasova, P. Phaal:
Hybrid and Predictive Admission Strategies
to Improve the Performance of an Overloaded Web Server.
HP Laboratories Report No. HPL-98-125R1, July, 1998.
- L. Cherkasova, P. Phaal: Session Based Admission Control:
a Mechanism for Improving the Performance of an
Overloaded Web Server.
HP Laboratories Report No. HPL-98-119, June, 1998.
|
