Research
Interests
- Autonomic Computing
- Cloud Computing
- Service Oriented Architectures
- Self-* properties of large scale distributed systems
- Economic Based Resource Allocation Algorithms
PhD Research
Collectives: a Middleware Framework for Self-Adaptive Distributed
Computations
The development of self-adaptive distributed computations faces many
challenges due to their increasingly complex requirements and the
openness of their environments. Therefore, along their development
process multiple adaptation concerns must be considered, such as the
response to changes in the utilization patterns, the need for
alternative algorithms for implementing a function, or the diversity of
the infrastructure.
The main objective of this research is to provide both the
abstractions needed to encapsulate all the relevant adaptation concerns
and the architecture to realize them. This clear separation of concerns
will allow a progressive transition from a high-level modeling of the
computation, to the design of the underlying algorithm and finally to
the full implementation into a real infrastructure, giving room for the
required adaptation at each stage.
Other Research
An Economic Based Framework for Self-Adaptive Grid Middleware
For Grids, with its intrinsic distribution, heterogeneity and
multi-institutional setups, the direct engineering of management
mechanism capable of handling the complexity of the environment and the
user demands has become an unattainable task. Autonomic Computing has
emerged as an alternative to build computing environments able to
modify its own behavior in response to changes in its operating
conditions However, some significant challenges still exits for the
definition of conceptual models, software architectures, middleware
platforms and application programming models for such systems.
The objective this research is the definition of a middleware
architecture that will use markets as a mechanism for self-adaptation.
Using principles from micro-economics and bounded rationality, this
middleware will translate user's objectives about application behavior
to economic goals and pursue them by competing in markets for the
virtualized resources provided by the grid platform. Resulting
interactions are expected to lead the system to a self-organized,
self-configured and self-optimized state of affairs.
Publications
2008
Chacin,
P., León, X., Brunner, R.,Freitag, F., Navarro, L. Core Services for Grid Markets,
CoreGrid Simposyum, Gran Canaria, Spain, Agust
2008.Abstract. Markets are a
powerful model for the coordination of distributed systems and, in
particular, in the face of incomplete information and changing
environments. The application of markets for the resource allocation in
grid systems has recently been researched as an alternative to
traditional approaches. However, the proper implementation of
sophisticated markets capable of handling diverse trading models
(various auctions types, bargaining) and structures (direct
negotiation, brokering, etc.) requires a set of supporting services to
provide participants a proper environment to engage in negotiations.
Grid Market Middleware (GMM) is a framework that aims to ease the
development of market based grid systems. In this paper we present its
architecture, the services it provides and describe how they can be
used to implement diverse market models. We also discuss our experience
with the implementation of prototypes for various core services.
2007
Chacin, P., Navarro, L. Collectives: A Framework for Self-adaptive
P2P Applications. 6th Workshop on Adaptive and Reflexive Middleware
(ARM2007) in conjuction with the 8th ACM/IFIP/USENIX International
Middleware Conference, New Port Beach, California, USA. 2007.Abstract. The development of a
self-adaptive P2P applications faces many challenges ranging from the
proper modeling of the application’s behavior to the definition of
the distributed algorithms required to support its functionalities and
finally to its implementation in a particular platform. Collectives is
a framework that addresses this issues by providing the modeling
concepts and the implementation architecture required to separate the
diverse adaptation concerns at the proper level of abstraction.
Freitag, F., Chacin, P., Chao, I.,
Brunner, R., Navarro, L., Ardaiz, O. Performance Measuring
Framework for Grid Market Middleware, 4th European
Performance Engineering Workshop (EPEW 2007), Berlin,
Germany,
2007Abstract. Current
implementations of Grid infrastructures provide frameworks which aim at
achieve on-demand computing. In such a scenario, contribution and use
of resources will be governed by business models. The challenge is to
provide multi-level performance information which enables the
participation of the different actors in such a system. In this paper
we describe the performance measuring framework developed for Grid
Market Middleware, a middleware which supports economic-model based
selection of service-oriented Grid applications. This middleware is a
distributed infrastructure, which we have implemented for providing a
market of services and resources to be assigned to Grid applications.
The objectives of the performance measuring framework is first to
assess the behaviour of the middleware and the used economic models in
a deployed system, and secondly allow the provision of metrics for the
components of the middleware itself. We describe the design of the
performance measuring framework, its implementation and show its
capability and usefulness for our objectives by experiments.
Joita L., Rana O.F., Chao I., Chacin
P., Freitag F., Navarro L., and Ardaiz, O. Service Level Agreements in
Catallaxy-based Grid Markets, Workshop
on Usage of Service Level Agreements in Grids, in conjuction
with The 8th IEEE International Conference on Grid Computing (Grid
2007),Austin, Texas, USA, 2007Abstract. Grid computing is an
important paradigm for managing computationally demanding applications
composed of a collection of services. This paper presents the
experience of using Service Level Agreements (SLAs) within the context
of a Catallactic enabled “proof-of-concept” prototype, where the
dynamic discovery of services and resources, and the selection of a
particular service instance are based on Catallactic oriented Grid
markets. The Catallactic-enabled applications are introduced and
evaluated via the social utility economic factor.
Brunner R., Chao I., Chacin
P., Freitag F., Navarro L., Ardaiz O., Joita L., and Rana
O.F. Assessing a distributed market infrastructure
for eco-nomics-based service selection. International
Conference on Grid computing, High-Performance and Distributed
Applications (GADA'07), Algarve,
Portugal, 2007Abstract. Service selection is
an important issue for market-oriented Grid infrastructures. However,
few results have been published on the use and evaluation of market
models in deployed prototypes, making it difficult to assess their
capabilities. In this paper we study the integration of an extended
version of Zero Intelligence Plus (ZIP) agents in a middleware for
economics-based selection of Grid services. The advantages of these
agents compared to alternatives is their fairly simple messaging
protocol and negotiation strategy. By deploying the middleware on
several machines and running experiments we observed that services are
proportionally assigned to competing traders as should be in a fair
market. Furthermore, varying the environmental conditions we show that
the agents are able to respond to the varying environmental constraints
by adapting their market prices.
2006
Joita, L.; Rana, O.F.; Chacin, P.; Chao, I.; Freitag, F.; Navarro,
L.; Ardaiz, O., "Application Deployment on Catallactic Grid
Middleware," Distributed Systems Online, IEEE , vol.7, no.12,
pp.1-1, Dec. 2006Abstract. An architecture based
on a decentralized market view integrates grid applications with
catallactic middleware. A prototype application showed the concept's
feasibility, as well as the middleware's effectiveness in balancing
query-request workload across multiple grid services. Grid computing
researchers have shown significant interest in using an economic
paradigm for exchanging grid resources and services. With this
approach, applications can use a market mechanism to schedule services
access, thus giving them a fair, efficient way to share resources in
high-demand periods. Most existing approaches rely on centralized
brokers to coordinate resource access, and they're typically
implemented over existing grid middleware. We propose an alternative
approach based on F.A. Hayek's Catallaxy mechanism. Catallaxy's
free-market, self-organizing coordination mechanisms adjust prices
within the market based on the particular demands for a specific
(scarce) resource
Pablo Chacin, Liviu Joita, Björn Schnizler, Felix Freitag,
Flexible Architecture for Supporting Auctions in Grids, Workshop in
Smart Grid Technologies on the Internacional Conference on Autonomic
Computing (ICAC 2006), Dublin, Ireland, July 16, 2006Abstract. Efficient and
flexible resource allocation is one of the key factors for a wide
application of Grids in business and scientific areas. Recently, the
use of auctions for scheduling and allocating Grid resources has been
proposed in literature. Hitherto, however, only few of the proposed
mechanisms are integrated in Grid infrastructures. Furthermore, none of
these proposals are applied in commercial settings. One reason for
this lays in technical challenges such as replacing discovery and
matchmaking mechanisms by auctions have to be overcome in order to
integrate an auction mechanism into a Grid platform. Another barrier
for a wide deployment of Grid auctions is that an allembracing auction
mechanism may not exist. A technical and economic sound architecture
thus has to support the simultaneous deployment of multiple different
auction instances. The paper introduces a flexible economic Grid
middleware which abstracts from the underlying technical infrastructure
and supports the simultaneous instances and management of a wide
spectrum of different auction. The design concepts of such system are
outlined and an ongoing prototype is presented, using the integration
of a MACE auction as a case study.
[pdf]
2005
Liviu Joita, Omer Rana, Pablo Chacin, Oscar Ardaiz, Isaac Chao,
Felix Freitag, Leandro Navarro, Application Deployment Using the
Catallactic Grid Middleware, I Workshop on Middleware for Grid
Computing in the ACM/USENIX/IFIP Middleware 2006, Grenoble,
France, November 28-29, 2005Abstract. In this paper we
describe an application deployment using a Catallactic Grid-enabled
middleware, which is based on the Catallaxy “free market”
self-organisation approach described by von Hayek, who understood the
market as a decentralised coordination mechanism opposite to a
centralised command economy. The implementation makes use of Globus
Toolkit, JXTA and WSRF. The paper envisages the resource virtualization
in the WSRF context as the main driver for a proper connection
middleware-base platform (on the broad scenario of grid
applications).
[pdf]
Pablo Chacin, Felix Freitag, Leandro, Isaac Chao,
Navarro, Oscar Ardaiz, Integration of Decentralized Economic Models
for Resource Self-Management in Application Layer Networks, Second
IFIP TC6 International Workshop on Autonomic Communications, Athens,
Greece, Octuber 3-5, 2005Abstract. Resource allocation
is one of the challenges for self-management of large scale distributed
applications running in a dynamic and heterogeneous environment.
Considering Application Layer Networks (ALN) as a general term for
such applications including computational Grids, Content Distribution
Networks and P2P applications, the characteristics of the ALNs and the
environment preclude an efficient resource allocation by a central
instance. The approach we propose integrates ideas from decentralized
economic models into the architecture of a resource allocation
middleware, which allows the scalability towards the participant
number and the robustness in very dynamic environments.At the same
time, the pursuit of the participants for their individual goals should
benefit the global optimization of the application. In this work, we
describe the components of this middleware architecture and introduce
an ongoing prototype.
[pdf]
Oscar Ardaiz, Pablo Chacin, Isaac Chao, Felix Freitag, Leandro
Navarro, An Architecture for Incorporating Decentralized Economic
Models in Application Layer Networks, International Journal on
Multiagent and Grid Systems. Special Issue on Smart Grid Technologies
Vol. 1(4), 2005Abstract. Efficient resource
discovery and allocation is one of the challenges of any large scale
Application Layer Network (ALN) such as computational Grids, Content
Distribution Networks and P2P applications. In centralized approaches,
the user requests can easily be matched to the most convenient
resource. These approaches, however, present scalability limits in the
highly dynamic and complex ALN environments. This paper, explores an
architecture for incorporating fully decentralized economic mechanisms
for resource allocation. These mechanisms are implemented by a set of
trading agents that operate on behalf of the clients and service
providers, interacting over an overlay network and interfacing with
the underlying resources of the platform. A prototype of the proposed
architecture is presented and the practical implications of its
implementation in a grid scenario are discussed.
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