740 research outputs found
Adaptive online deployment for resource constrained mobile smart clients
Nowadays mobile devices are more and more used as a platform for applications. Contrary to prior generation handheld devices configured with a predefined set of applications, today leading edge devices provide a platform for flexible and customized application deployment. However, these applications have to deal with the limitations (e.g. CPU speed, memory) of these mobile devices and thus cannot handle complex tasks. In order to cope with the handheld limitations and the ever changing device context (e.g. network connections, remaining battery time, etc.) we present a middleware solution that dynamically offloads parts of the software to the most appropriate server. Without a priori knowledge of the application, the optimal deployment is calculated, that lowers the cpu usage at the mobile client, whilst keeping the used bandwidth minimal. The information needed to calculate this optimum is gathered on the fly from runtime information. Experimental results show that the proposed solution enables effective execution of complex applications in a constrained environment. Moreover, we demonstrate that the overhead from the middleware components is below 2%
Implementing the Gaia Astrometric Global Iterative Solution (AGIS) in Java
This paper provides a description of the Java software framework which has
been constructed to run the Astrometric Global Iterative Solution for the Gaia
mission. This is the mathematical framework to provide the rigid reference
frame for Gaia observations from the Gaia data itself. This process makes Gaia
a self calibrated, and input catalogue independent, mission. The framework is
highly distributed typically running on a cluster of machines with a database
back end. All code is written in the Java language. We describe the overall
architecture and some of the details of the implementation.Comment: Accepted for Experimental Astronom
Forum Session at the First International Conference on Service Oriented Computing (ICSOC03)
The First International Conference on Service Oriented Computing (ICSOC) was held in Trento, December 15-18, 2003. The focus of the conference ---Service Oriented Computing (SOC)--- is the new emerging paradigm for distributed computing and e-business processing that has evolved from object-oriented and component computing to enable building agile networks of collaborating business applications distributed within and across organizational boundaries. Of the 181 papers submitted to the ICSOC conference, 10 were selected for the forum session which took place on December the 16th, 2003. The papers were chosen based on their technical quality, originality, relevance to SOC and for their nature of being best suited for a poster presentation or a demonstration. This technical report contains the 10 papers presented during the forum session at the ICSOC conference. In particular, the last two papers in the report ere submitted as industrial papers
Using Java for distributed computing in the Gaia satellite data processing
In recent years Java has matured to a stable easy-to-use language with the
flexibility of an interpreter (for reflection etc.) but the performance and
type checking of a compiled language. When we started using Java for
astronomical applications around 1999 they were the first of their kind in
astronomy. Now a great deal of astronomy software is written in Java as are
many business applications.
We discuss the current environment and trends concerning the language and
present an actual example of scientific use of Java for high-performance
distributed computing: ESA's mission Gaia. The Gaia scanning satellite will
perform a galactic census of about 1000 million objects in our galaxy. The Gaia
community has chosen to write its processing software in Java. We explore the
manifold reasons for choosing Java for this large science collaboration.
Gaia processing is numerically complex but highly distributable, some parts
being embarrassingly parallel. We describe the Gaia processing architecture and
its realisation in Java. We delve into the astrometric solution which is the
most advanced and most complex part of the processing. The Gaia simulator is
also written in Java and is the most mature code in the system. This has been
successfully running since about 2005 on the supercomputer "Marenostrum" in
Barcelona. We relate experiences of using Java on a large shared machine.
Finally we discuss Java, including some of its problems, for scientific
computing.Comment: Experimental Astronomy, August 201
Towards Grid Monitoring and deployment in Jade, using ProActive
This document describes our current effort to gridify Jade, a java-based
environment for the autonomic management of clustered J2EE application servers,
developed in the INRIA SARDES research team. Towards this objective, we use the
java ProActive grid technology. We first present some of the challenges to turn
such an autonomic management system initially dedicated to distributed
applications running on clusters of machines, into one that can provide
self-management capabilities to large-scale systems, i.e. deployed on grid
infrastructures. This leads us to a brief state of the art on grid monitoring
systems. Then, we recall the architecture of Jade, and consequently propose to
reorganize it in a potentially more scalable way. Practical experiments pertain
to the use of the grid deployment feature offered by ProActive to easily
conduct the deployment of the Jade system or its revised version on any sort of
grid
A Novel Mechanism for Gridification of Compiled Java Applications
Exploiting Grids intuitively requires developers to alter their applications, which calls for expertise on Grid programming. Gridification tools address this problem by semi-automatically making user applications to be Grid-aware. However, most of these tools produce monolithic Grid applications in which common tuning mechanisms (e.g. parallelism) are not applicable, and do not reuse existing Grid middleware services. We propose BYG (BYtecode Gridifier), a gridification tool that relies on novel bytecode rewriting techniques to parallelize and easily execute existing applications via Grid middlewares. Experiments performed by using several computing intensive applications on a cluster and a simulated wide-area Grid suggest that our techniques are effective while staying competitive compared to programmatically using such services for gridifying applications
PicoGrid: A Web-Based Distributed Computing Framework for Heterogeneous Networks Using Java
We propose a framework for distributed computing applications in heterogeneous networks. The system is simple to deploy and can run on any operating systems that support the Java Virtual Machine. Using our developed system, idle computing power in an organization can be harvested for performing computing tasks. Agent computers can enter and leave the computation at any time which makes our system very flexible and easily scalable. Our system also does not affect the normal use of client machines to guarantee satisfactory user experience. System tests show that the system has comparable performance to the theoretical case and the computation time is significantly reduced by utilizing multiple computers on the network
SMArc: a proposal for a smart, semantic middleware architecture focused on Smart City energy management
Among the main features that are intended to become part of what can be expected from the Smart City, one of them should be an improved energy management system, in order to benefit from a healthier relation with the environment, minimize energy expenses, and offer dynamic market opportunities. A Smart Grid seems like a very suitable infrastructure for this objective, as it guarantees a two-way information flow that will provide the means for energy management enhancement. However, to obtain all the required information, another entity must care about all the devices required to gather the data. What is more, this entity must consider the lifespan of the devices within the Smart Grid—when they are turned on and off or when new appliances are added—along with the services that devices are able to provide. This paper puts forward SMArc—an acronym for semantic middleware architecture—as a middleware proposal for the Smart Grid, so as to process the collected data and use it to insulate applications from the complexity of the metering facilities and guarantee that any change that may happen at these lower levels will be updated for future actions in the system
A Fault Tolerant and Multi-Paradigm Grid Architecture for Time Constrained Problems. Application to Financial Option Pricing
International audienceThis paper introduces a Grid software architecture offering fault tolerance, dynamic and aggressive load balancing and two complementary parallel programming paradigms. Experiments with financial applications on a real multi-site Grid assess this solution. This architecture has been designed to run industrial and financial applications, that are frequently time constrained and CPU consuming, feature both tightly and loosely coupled parallelism requiring generic programming paradigm, and adopt client-server business architecture
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