Many real-time applications need data services in distributed environments. However, providing such data services is a challenging task due to long remote data accessing delays and stringent time requirements of real-time transactions. Replication can help distributed real-time database systems meet the stringent time requirements of application transactions. In this paper, we present two dynam...

Physics experiments that generate large amounts of data need to be able to share it with researchers around the world. High performance grids facilitate the distribution of such data to geographically remote places. Dynamic replication can be used as a technique to reduce bandwidth consumption and access latency in accessing these huge amounts of data. We describe a simulation framework that we...

The replication of the non-structure data from one data center to another is an urgent task in HBase. The paper studies the priority growth probability of the priority replication queue and proposed a dynamic priority replication task queue algorithm based on the earliest deadline first algorithm (EDF). The experiment results show that the proposed algorithm can balance the replication overhead...

Optimising the use of Grid resources is critical for users to effectively exploit a Data Grid. Data replication is considered a major technique for reducing data access cost to Grid jobs. This paper evaluates a novel replication strategy, based on an economic model, that optimises both the selection of replicas for running jobs and the dynamic creation of replicas in Grid sites. In our model, o...

As for the problem of how to carry out task scheduling and data replication effectively in the grid and to reduce task’s execution time, this thesis proposes the task scheduling algorithm and the optimum dynamic data replication algorithm and builds a scheme to effectively combine these two algorithms. First of all, the scheme adopts the ISS algorithm considering the number of tasks waiting que...

The ever-increasing popularity of peer-to-peer (P2P) systems provides a strong motivation for designing a dependable P2P system. Dependability in P2P systems can be viewed from two different perspectives, namely system reliability (the availability of the individual peers) and system performance (data availability). This paper looks at dependability from the viewpoint of system performance and ...

In large systems, data management is only possible through the use of replication techniques. In order to improve availability and ensure fast and efficient access, we propose in this paper a dynamic replication algorithm which takes into account also the placement of data in a hierarchical data grid. Experimental results show the effectiveness of our approach in terms of response time and avai...

Unlike traditional high performance computing environment, such as supercomputers, the cloud computing is a collection of interconnected and virtualized computing resources that are managed to be one or more unified computing resources. The Cloud environment constitutes a heterogeneous and a highly dynamic environment. Failures on the data centers storage nodes are normal rather than exceptiona...

As fault tolerance is the ability of a system to perform its function correctly even in the presence of faults. Therefore, different fault tolerance techniques are critical for improving the efficient utilization of expensive resources in high performance data grid systems. One of the most popular strategies of fault tolerance is the replication, it creates multiple copies of resources in the s...