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Mobile
Agents introduces a new form of distributed computing. Establishing mobile
agents as a vital such paradigm requires the study of its applicability in
various domains. Thus, we have introduced mobile agents in the area of
database and parallel processing. Furthermore, being a new paradigm we
have introduced appropriate performance metrics and evaluations.
The
popularity of Web as a universal access mechanism for network information
has created the need for developing web-based DBMS client/server
applications. However, the current commercial applet-based methodologies
for accessing database systems offer limited flexibility, scalability and
robustness. In this work, we propose a new framework for Web-based
distributed access to database systems based on Java-based mobile agents.
The framework supports lightweight, portable and autonomous clients as
well as operation on slow or expensive networks. The implementation of the
framework using the aglet workbench shows that its performance is
comparable to, and in some case outperforms, the current approach. In
fact, in wireless and dial-up environments and for average size
transactions, a client/agent/server adaptation of the framework provides a
performance improvement of approximately a factor of ten. For the fixed
network, the gains are about 40% and 30% respectively. We expect our
framework to perform even better when deployed using different
implementation platforms as indicated by our preliminary results
from an implementation based on Voyager.
We
are currently extending the DBMS-Aglet
Framework to create a complete library of database agents (i.e., view
agents, warehouse agents, backup agents) from which a user can pick and
instantiate the agent required by a specific application.
Introducing transactional semantics into the mobile agent-computing
paradigm is also in progress.
Related
Publications:
 |
C.
Spyrou, G. Samaras, E. Pitoura, S. Papastavrou, P. K. Chrysanthis, The Dynamic View System
(DVS): Mobile Agents to Support Web Views (demo). In the 17h International Conference on Data Engineering
(ICDE01), Heidelberg, Germany, April 2-6, 2001.
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Papastavrou
S., G. Samaras, E. Pitoura, “Mobile
Agents for WWW Distributed Database Access”, IEEE
Transactions on Knowledge and Data Engineering Journal (TKDE),
Vol. 12, No. 5 September/October 2000. |
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Constantinos
Spyrou, George Samaras, Evaggelia Pitoura, Stavros Papastavrou, and Panos K.
Chrysanthis, “Mobile
Agents to Support Views for Wireless and Mobile Client”, Proc.
17th International Data
Engineering Conference (ICDE 2001),
demo session, Germany,
April 2-6 2001.
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George Samaras and
Paraskevas Evripidou, Evangelia Pitoura,
“Mobile-Agents based
Infrastructure for eWork and eBussiness Applications”, The eBusiness and eWork Conference, eWork2000, Madrid, Spain, October
2000.
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Papastavrou
S., G. Samaras, E. Pitoura, “Mobile
Agents for WWW Distributed Database Access”,
Proc. 15th International
Data Engineering Conference, pp. 228-237, Sydney, Australia, March
1999. ICDE´99
Best Paper Award. (Accepted rate: 22%)
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Samaras G.,
Dikaiakos M., Spyrou C.,
Liberdos A., “Mobile Agent Platforms for Web-Databases: A Qualitative and
Quantitative Assessment”, The
Joint Symposium ASA/MA'99. First
International Symposium on Agent Systems and Applications (ASA'99).
Third International Symposium on Mobile Agents (MA'99), pp. 50-64,
USA, 1999. (Accepted rate: 22%) |
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Stavros
Papastavrou, Panos K. Chrysanthis, George Samaras, Evaggelia Pitoura,
“An Evaluation of the Java-based Approaches for Web Database Access”,
International Journal of Cooperation Systems (IJCIS), special issue.
(accepted)
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PaCMAn
(Parallel Computing with Java Mobile
Agents) launches multiple
Java-mobile Agents that communicate and cooperate to solve problems in
parallel. Each mobile agent can travel anywhere in the web to perform its
tasks. We also introduce the concept of task-handlers, which are Java
objects capable of implementing a particular task of the target
application. TaskHandlers are dynamically assigned to PaCMAn’s
mobile agents. A number of brokers/load forecasters keep track of the
available resources, they also provide load forecast to the clients. The
clients select the servers that they will utilize based on the specific
resource requirements and of course the load forecast. We have developed
and tested a prototype system with several applications such as Parallel
Web Querying, Prime number generator, Trapezoidal rule and the RC5
cracking application. This prototype provides proof of concept for our
proposed framework. Furthermore it has demonstrated that PaCMAn
provides very good parallel efficiency.
Related
Publications:
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Evripidou
P., Samaras G., Pitoura E., Christoforos P.,
“The PacMan Metacomputer: Parallel Computing with Java Mobile Agents”,
Journal FGCS special issue on JAVA in High Performance Computing,
Vol 19, No. 2 (2001) pp 265-280. [ Visit
Homepage ] |
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Evripidou P.,
Samaras G., Pitoura E., Christoforos P.,
“PacMan: Parallel Computing Using Java Mobile Agents”,
13th ACM International Conference on Supercomputing (ICS),
Workshop on “Java for High Performance Computing”, Rhodes,
Greece, June 1999.
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Christoforos P.,
Samaras G., Pitoura E., Evripidou P.,
“Parallel Computing Using
Java Mobile Agents”,
25th Euromicro Conference, Workshop on Network Computing, September
1999. Also technical report TR-99-7, University of Cyprus,
February 1999. |
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Barelos,
D., E. Pitoura, G. Samaras, “Mobile
Agents Procedures: Metacomputing in Java”,
Proc. Of the ICDCS Workshop on Distributed
Middleware
(in conjunction with the 19th IEEE International Conference on
Distributed Computing Systems (ICDCS99)), pp. 90-95, Austin, TX USA,
June
1999.
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Paraskevas
Evripidou, George Samaras, Constantinos Spyrou,
Andreas Papagapiou, “Net-Console:
A Web Based Development Environment for Parallel Programs”, Parallel
Processing Letters special issue on Parallel Processing in the
New Millennium. (accepted) |
Wireless
mobile computing breaks the stationary barrier and allows users to compute
and access information anywhere and anytime. However, the severe
restrictions induced by wireless connectivity and mobility have a great
impact on the design and structure of mobile computing applications and
motivate the development of new computing models. To this end, a number of
extensions to the traditional distributed system architectures have been
proposed. These new software models, however, are static and require a
priori set up and configuration. This in effect limits their potential in
dynamically serving the mobile client; the client can not access a site
where an appropriate model is not configured in advance. The contribution
of this work is twofold. First, it shows how an implementation of the
proposed models using mobile agents eliminates this limitation and
enhances the utilization of the models. Second, new frameworks for
Web-based distributed access to databases are proposed and implemented via
mobile agents.
Related
Publications:
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Constantinos
Spyrou,
George Samaras, Evangelia Pitoura,
Evripidou Paraskevas,
“Wireless Computational Models: Mobile Agents to the Rescue”,
2nd International Workshop “Mobility in Databases &
Distributed Systems” DEXA´99, Florence, Italy, September 1999.
(Accepted rate: 30%) (selected for Journal publication) |
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Samaras
G., Dikaiakos M., Spyrou C.,
Liberdos A., “Mobile Agent Platforms for Web-Databases: A Qualitative and
Quantitative Assessment”, The
Joint Symposium ASA/MA'99. First
International Symposium on Agent Systems and Applications (ASA'99).
Third International Symposium on Mobile Agents (MA'99), pp. 50-64,
USA, 1999. (Accepted rate: 22%)
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Constantinos
Spyrou, George Samaras, Evangelia Pitoura,
Evripidou Paraskevas
“Mobile
Agents for Wireless Computing: The Convergence of Wireless
Computational Models with Mobile-Agent Technologies”,
Journal of ACM/Baltzer Mobile Networking and Applications (MONET),
special issue on
“Mobility
in Databases & Distributed Systems
", 2001. (to appear) |
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Paraskevas
Evripidou, George Samaras, Constantinos Spyrou,
Andreas Papagapiou, “Net-Console:
A Web Based Development Environment for Parallel Programs”, Parallel
Processing Letters special issue on Parallel Processing in the
New Millennium.(accepted) |
| Samaras,
G., E. Pitoura, and P. Evripidou “Software
Models for Wireless and Mobile Computing: Survey
and Case Study”.
To the Journal of ACM/Baltzer Mobile Networking and Applications (MONET),
TR# 99-5, University of Cyprus, Computer Science Department. |
In
this work we present practical experiences gathered from the employment
of two popular
Java-based Mobile
Agent platforms, IBM
Aglets and Mitsubishi's Concordia.
These platforms have been used to develop
a framework
for distributed
database access
over the World-Wide
Web. We compare
the two platforms both quantitatively and qualitatively.
For the quantitative comparison, we propose and employ an
approach to
evaluate and
analyze Mobile
Agent framework
performance. For
the qualitative
assessment, we present
our observations from the point of view of programmability,
robustness and mobility provided by the two platforms.
Related
Publications:
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M.
Dikaiakos, Melinos k., G. Samaras, "A
Performance Analysis Framework for Mobile-Agent Systems, " 5th
International Conference on Mobile Agents. Atlanta, Georgia, USA,
December 2 - 4, 2001. Published by Springer-Verlag in the Lecture
Notes on Computer Science series. (Accepted rate: 24%)
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M.
Dikaiakos, G.
Samaras, "A Performance Analysis Framework for Mobile-Agent
Systems, "First Annual Workshop on Infrastructure for Scalable
Multi-Agent Systems, The Fourth
International Conference on Autonomous Agents 2000, ACM,
Barcelona, June 2000. Published by Springer-Verlag in the Lecture
Notes on Computer Science series.
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Samaras
G.,
Dikaiakos M., Spyrou C.,
Liberdos A., “Mobile Agent Platforms for Web-Databases: A Qualitative and
Quantitative Assessment”, The
Joint Symposium ASA/MA'99. First
International Symposium on Agent Systems and Applications (ASA'99).
Third International Symposium on Mobile Agents (MA'99), pp. 50-64,
USA, 1999. (Accepted rate: 22%) |
|
Constantinos
Spyrou, George Samaras, Evangelia Pitoura,
Evripidou Paraskevas
“Mobile
Agents for Wireless Computing: The Convergence of Wireless
Computational Models with Mobile-Agent Technologies”,
Journal of ACM/Baltzer Mobile Networking and Applications (MONET),
special issue on
“Mobility
in Databases & Distributed Systems
", 2001. (to appear) |
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