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Data Grid provides geographically distributed storage resources for large-scale data-intensive applications that generate large data sets. Because data is the important resource in data grids, an efficient management is needed to minimize the response time of applications. Replication is typically used in data grids to improve access time and to reduce the bandwidth consumption. In this paper, we...
Genetic algorithms are becoming increasingly valuable in solving large-scale, realistic, difficult problems, and selecting replica with multiple selection criteria - availability, security and time- is one of these problems. In this paper, a rank based elitist clustering Genetic Algorithm is proposed named RRWSGA, which alleviates the problem of being trapped in local clustering centroids using k-mean...
Availability of grid resources is dynamic, which raises the need to develop robust and effective applications against changing circumstances. A major challenge in a distributed dynamic grid is fault tolerance. The more resources and components involved the more complicated and error-prone the system becomes. In a grid with potentially thousands of machines connected to each other, the reliability...
The data replication is a very important technique for the availability of data in the grids. One of the challenges in data replication is the replicas placement. In this paper, we present our contribution by proposing a replicas placement strategy in a hierarchical grid. Our approach is based on a dynamic threshold, contrary to the other strategies of replicas placement which use a static threshold...
Computational grids have the potential for solving large-scale scientific problems using heterogeneous and geographically distributed resources. However, a number of major technical hurdles must overcome before this potential can be realized. One problem that is critical to effective utilization of computational grids and gives a certain Quality of Service (QoS) for grid users is the efficient co-allocation...
Security infrastructure is one of the most challenging tasks in the development, integration and deployment of Grid middle wares. Even though the Grid community addresses the security issue through public key infrastructures (PKI) to support mutual authentication using X.509 certificates, maintaining X.509 credentials is not that easy for non-IT-experts, and has proved to be an obstacle for a more...
Grid and cloud schedulers benefit from predictable service for their choices in allocating jobs on remote servers/clusters. Predictable service on local clusters supports fairness and user satisfaction. The paper looks into servers that employ batch scheduling and support time sharing and/or space partitioning of the available resources among different parallel-job workloads. This provides the basis...
In this paper, we study the impact of tasks reallocation onto a multi-cluster environment where clusters are heterogeneous and use different resources management policies. In this context, we propose a reallocation mechanism that migrates waiting jobs from one cluster to another. We performed simulations using real traces to study benefits of reallocations. We compared two algorithms providing the...
Complex applications in e-science and e-business are usually modeled as workflows, which often require the power of the Grid to run efficiently. Cost optimization for workflow applications with deadline constraints is a fundamental problem on Grids. In this paper, a workflow scheduling algorithm that minimizes execution cost while meeting the deadline is proposed. The proposed solution consists of...
Complex applications are usually modeled as workflows, which are often represented by Directed Acyclic Graph (DAG) and require the power of Grid to run efficiently. Cost-optimized workflow scheduling under deadline constraints is a fundamental and intractable problem on Grids. In this paper, an effective and efficient heuristic for workflow scheduling is proposed. A mixed integer programming (MIP)...
The short utility lifetime of performance monitoring information is an important consideration in the design of grid monitoring architecture. Disseminating fresh performance information quickly and accurately to satisfy thousands of potential requests is a challenge for Information Service. We propose a request scheduling mechanism that considers the indexes and urgency of information request. This...
Data grids provide the data-intensive applications with a large virtual storage framework. We use a reputation-based trust aggregation approach for data providers to quantitatively predict and calculate whether or not they are reliable and credible. In the same time, adaptable trust service is increasingly important for applications running on data grids. However, existing systems are unable to satisfy...
In computational grid environment, the task scheduling problem can be stated as finding a schedule scheme for a series of tasks to be executed on multiple resources, so that the task completion time can be minimized. There have been a lot of researches on scheduling algorithm, and heuristic approach have played very good role. For example, Genetic Algorithms, Simulated Annealing Algorithm, Ant Colony...
We investigate the sequential task anycast scheduling problem (STAS) for grid applications in an optical burst switched network. In STAS, the subtasks of a given request have sequential dependency and must be processed in order. Each node in the network provides a set of services and each subtask may demand a different type of service. The problem is to find an ordered set of nodes that can minimize...
In order to better solve the problem of distributed query optimization, a querying optimization algorithm on GEP (QO-GEP) is present. On the basis of QO-GEP, distributed GEP query optimization on grid service (DGEPQO-GS) is proposed which combines with grid service. Simulated experiments shows that with the increment of the number of query relation, query time which QO-GEP carries out querying decreases...
Monitoring gird resources using Web Service is an important issue in grid computing. Although some concern has been given to the Index Service scalability with increasing grid resources, the overhead of processing thousands of resource information requests may cause performance problems in Index service for grid monitoring. This paper proposed a replica scheduling mechanism based on load balancing...
Nowadays, Data Grids can be seen as a frameworks responding to the needs of large scale applications by affording varied geographically distributed resources set. The main aim here is to ensure flexible and efficient access and quality data, to improve the availability and accessibility, we must improve scalability and efficient usability of Grid to reduce application communication costs and request...
In this paper we evaluate performance of three different site allocation policies in a 2-level computational grid with heterogeneous sites. We consider that schedulers are aware of service demands of jobs which show high variability. A simulation model is used to evaluate performance in terms of the average response time and slowdown, under medium and high load. Simulation results show that the proposed...
Nowadays, medium or large-scale distributed infrastructures such as clusters and grids are widely used to host various kinds of applications (e.g. web servers or scientific applications). Resource management is a major challenge for most organizations that run these infrastructures. Many studies show that clusters are not used at their full capacity and that there are therefore a huge source of waste...
Grid computing is emerging as a key enabling infrastructure for a wide range of disciplines in Science and Engineering. Data grids provide distributed resources for dealing with large scale applications that generate huge volume of data sets. Data replication, a technique much discussed by data grid researchers in past years creates multiple copies of file and stores them in conventional locations...
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