Relais: cooperative caches for the
World-Wide Web
Cliquez ici pour la version française
Overview
The Relais project aims at improving the quality of service of the
Web by using caching and mirroring techniques.
The Relais cooperative caching protocol
The Relais protocol allows a group of caches
distributed world-wide to cooperate in order to improve Web
performances, while reducing Internet traffic as well as the servers'
load. Relais guarantees to its clients a monotonic and rapid progress
on the documents' versions. Once a cache learns that some document is
stale, Relais takes care of the refreshment of all partners caching
this document. For performance reasons, actions required to enforce
consistency are performed in background. Relais efficiently locates
documents. This requires only an access to a local directory.
Finally, Relais has been prototyped on top of Squid. A release of
Relais has been in daily use by our group since January 1997.
For more information, you can have a look at this small présentation or this more
detailed one...
Caching system performance evaluation
Consider designing a cache architecture in order to
improve an Intranet's access to the World-Wide Web. The problem is to
figure out how many caches are required, where to place them, what
kind of cooperation to use between them, and which caching algorithms
and configuration are optimal. To aid in such decisions, we propose a
trace-driven simulation technique. We capture the actual traffic of
the target Intranet, and simulate the behavior of several cache
configurations in this situation. To evaluate the user-perceived
performance of the system, we use two metrics: speed and
consistency. We show how to collect and use the necessary data. Our
tool evaluates the resulting speed and consistency performance of
several candidate configurations.
For more information, you can have a look at this small présentation or this more
detailed and up-to-date one
...
The prototypes
- Relais : the cooperative
Web cache.
- Saperlipopette! v0.3 : the
distributed Web caches simulation tool.
- Pandora: a Flexible
Network Monitoring Platform.

- Pluxy,
a dynamically expendable Web proxy (released by our colleagues
from Pharos).
Publications about Relais
- Pandora: A Flexible Network Monitoring Platform.
Simon Patarin and Mesaac Makpangou. INRIA Research Report RR-3834, december 1999.

- Pandora : un
système de collecte de traces du trafic Web de
communautés d'utilisateurs réparties.
Simon Patarin. INRIA Research Report RR-3743, july 1999 (in
French with an abstract in English).
- Architecture et
dimensionnement d'infrastructures de caches Web pour Intranets
décentralisés. Guillaume Pierre. PhD thesis, June 1999
(in French with an abstract and the
defense slides in English).

- ARÃ : Un système de gestion
des miroirs sur Internet. Neilze Dorta. In proceedings
of Journée des Jeunes
Chercheurs en Systèmes (JCS '99), June 1999. (in
French)
- Replicated Directory
Service for Weakly Consistent Replicated Caches. Mesaac
Makpangou, Guillaume Pierre, Christian Khoury and Neilze
Dorta. In proceedings of the ICDCS '99
conference, may 1999. Also appeared as INRIA Research Report
RR-3514, October 1998.
- Saperlipopette!: a
Distributed Web Caching Systems Evaluation
Tool. Guillaume Pierre and Mesaac Makpangou. In
proceedings of the 1998
Middleware conference, september 1998. Also appeared as INRIA research
report RR-3388, March 1998.
- Conception d'un
système de cache Web adapté aux spécificités des
utilisateurs. Guillaume Pierre. In Proceedings of the NoTeRe '98
colloquium, October 1998. (in French with an abstract in
English)
- Relais : un
protocole de maintien de cohérence de caches Web
coopérants. Mesaac Makpangou and Éric Bérenguier. In
proceedings of the NoTeRe '97
colloquium, November 1997. (in French with an abstract in
English)
- Oléron:
Supporting Information Sharing in Large-Scale Mobile
Environments. Aline Baggio and Guillaume Pierre. In
proceedings of the ERSADS workshop, March
1997.
See also
People involved
For more informations about Relais, please contact
Mesaac Makpangou.
Last modified: Tue Aug 8 15:15:28 EDT 2000
Guillaume Pierre