In distributed systems one of the main requirements is searching on distributed data which are sometimes inherently dispersed and exists in large volume. Current systems have different approaches to this problem and a...
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In distributed systems one of the main requirements is searching on distributed data which are sometimes inherently dispersed and exists in large volume. Current systems have different approaches to this problem and address certain aspects of it. In this paper we propose a general solution which can be configured according to the problem requirements and is designed based on grid environment. grid technology has solved many problems of sharing resources (e.g. data) and their information (e.g. indices) for searching on them, and can be used as an appropriate infrastructure for doing this general search.
We introduce component-oriented programming as a new level of object-oriented programming over grid and present a component framework for the DG-ADAJ (Desktop top grid - Adaptive distributed Application in Java). DG-A...
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We introduce component-oriented programming as a new level of object-oriented programming over grid and present a component framework for the DG-ADAJ (Desktop top grid - Adaptive distributed Application in Java). DG-ADAJ is a middleware platform which gives an execution and programming environment intended for distributed application over a Desktop grid. It is designed and implemented above the Java/RMI platforms according to a multi-layer structure. It makes it possible to express Java object distribution over the Desktop grid which is relatively transparent for the programmers and it provides several mechanisms for object migration and for optimized static and dynamic object placement. The component framework based on the Java object-oriented programming CCADAJ is developed as a CCA-compliant framework over the DG-ADAJ with a not expensive additional cost.
gridcomputing aims to integrate large number of heterogeneous, geographically distributed resources and services to create the illusion of a simple and powerful virtual supercomputer. Clearly, security is a serious c...
gridcomputing aims to integrate large number of heterogeneous, geographically distributed resources and services to create the illusion of a simple and powerful virtual supercomputer. Clearly, security is a serious concern in such a big environment. The environment needs to be secure in terms of access and communication in order for it to be widely used and acceptable. The large number of user base and administrative domains, with differing security requirements, policies and trust relationships, interact in a complex manner to access resources. This give rise to security problems that are not addressed by traditional distributedcomputing environments. This paper presents, at a high level, web services security specifications based security model to address security requirements of grid services. The model is simple, flexible, adaptable and is based on extended use of web services security specifications. We also present a prototype implementation of the proposed model.
In wide-area gridcomputing, geographically distributed computational resources are connected for enabling efficient and large-scale scientific/engineering computations. In the wide-area gridcomputing, a data transfe...
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ISBN:
(纸本)9780780392762
In wide-area gridcomputing, geographically distributed computational resources are connected for enabling efficient and large-scale scientific/engineering computations. In the wide-area gridcomputing, a data transfer protocol called gridFTP has been commonly used for large file transfers. gridFTP has the following features for solving problems of the existing TCP. First, for accelerating the start-up in TCP's slow start phase and achieving high throughput in TCP's congestion avoidance phase, multiple TCP connections can be established in parallel. Second, according to the bandwidth-delay product of a network, the TCP socket buffer size can be negotiated between gridFTP server and client. However, in the literature, sufficient investigation has not been performed either on the optimal number of TCP connections or the optimal TCP socket buffer size. In this paper, we therefore quantitatively investigate the optimal parameter configuration of gridFTP in terms of the number of TCP connections and the TCP socket buffer size. We first derive performance metrics of gridFTP in steady state (i.e., goodput and packet loss probability). We then derive the optimal parameter configuration for gridFTP and quantitatively show performance limitations of gridFTP through several numerical examples. We also demonstrate validity of our approximate analysis by comparing simulation results with analytic ones.
In times of increasing grid oriented computing environments, the integration and orchestration of business services become more and more emergent. This challenge is taken in the context of the EU project Adapative Ser...
ISBN:
(纸本)3885793989
In times of increasing grid oriented computing environments, the integration and orchestration of business services become more and more emergent. This challenge is taken in the context of the EU project Adapative Services grid. As a base for the execution of workflow specifications a distributed execution environment for simple business services and service managment is needed. This paper shows how such environments can be designed and implemented as a result of the Adapative Services grid research.
Existing grid models target purely data parallel applications without inter-task communication. This paper proposes a transparent programming model to support communicating parallel tasks in a wide area grid. The prop...
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This paper integrates the concepts of realtime network monitoring and visualizations into a gridcomputing architecture on the Internet. We develop a Realtime Network Monitor(RNM) that performs realtime network monito...
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grid environments enable users to share non-dedicated resources that lack performance guarantees. This paper describes the design of application-centric middleware components to automatically recover from failures and...
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ISBN:
(纸本)0769522769
grid environments enable users to share non-dedicated resources that lack performance guarantees. This paper describes the design of application-centric middleware components to automatically recover from failures and dynamically adapt to grid environments with changing resource availabilities, improving fault-tolerance and performance. The key components of the application-centric approach are a global per-application execution history and an autonomic component that tracks the performance of a job on a grid resource against predictions based on the application execution history, to guide rescheduling decisions. Performance models of unmodified applications built using their execution history are used to predict failure as well as poor performance. A prototype of the proposed approach, an Autonomic Virtual Application Manager (AVAM), has been implemented in the context of the In-VIGO grid environment and its effectiveness has been evaluated for applications that generate CPU-intensive jobs with relatively short execution times (ranging from tens of seconds to less than an hour) on resources with highly variable loads - a workload generated by typical educational usage scenarios of In-VIGO-like grid environments. A memory-based learning algorithm is used to build the performance models for CPU-intensive applications that are used to predict the need for rescheduling. Results show that In-VIGO jobs managed by the AVAM consistently meet their execution deadlines under varying load conditions and gracefully recover from unexpected failures.
Data grid supports data-intensive applications in a large scale grid environment. It makes use of storage systems as distributed data stores by replicating contents. On the co-allocation architecture, the client can d...
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Transaction proceesing in grid is to ensure reliable execution of inherently distributedgrid applications. This paper1 proposes coordination algorithms for handling short-lived and long-lived grid transactions, model...
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