Reducing DRAM Access Latency via Helper Rows

This paper proposes a tree-based adaptive broadcasting (TAB) algorithm for data dissemination to improve data access efficiency. The proposed TAB algorithm first constructs a broadcast tree to determine the broadcast frequency of each data and splits the broadcast tree into some broadcast wood to generate the broadcast program. In addition, this paper develops an analytical model to derive the mean access latency of the generated broadcast program. In light of the derived results, both the index channel’s bandwidth and the data channel’s bandwidth can be optimally allocated to maximize bandwidth utilization. This paper presents experiments to help evaluate the effectiveness of the proposed strategy. From the experimental results, it can be seen that the proposed mechanism is feasible in practice.

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Policy Driven Negotiation to Improve the QoS in Data Grid

Encyclopedia of E-Business Development and Management in the Global Economy ◽

10.4018/978-1-61520-611-7.ch105 ◽

2010 ◽

pp. 1041-1056

Author(s):

Ghalem Belalem

Keyword(s):

Large Scale ◽

Data Access ◽

Data Grid ◽

Management Service ◽

Replica Placement ◽

Data Grids ◽

Large Scale Systems ◽

Consistency Management ◽

Access Latency ◽

Replicated Data

Data grids have become an interesting and popular domain in grid community (Foster and Kesselmann, 2004). Generally, the grids are proposed as solutions for large scale systems, where data replication is a well-known technique used to reduce access latency and bandwidth, and increase availability. In splitting of the advantages of replication, there are many problems that should be solved such as, • The replica placement that determines the optimal locations of replicated data in order to reduce the storage cost and data access (Xu et al, 2002); • The problem of determining which replica will be accessed to in terms of consistency when we need to execute a read or write operation (Ranganathan and Foster, 2001); • The problem of degree of replication which consists in finding a minimal number of replicas without reducing the performance of user applications; • The problem of replica consistency that concerns the consistency of a set of replicated data. This consistency provides a completely coherent view of all the replicas for a user (Gray et al 1996). Our principal aim, in this article, is to integrate into consistency management service, an approach based on an economic model for resolving conflicts detected in the data grid.

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Predictive File Replication on the Data Grids

Evolving Developments in Grid and Cloud Computing ◽

10.4018/978-1-4666-0056-0.ch005 ◽

2012 ◽

pp. 67-83

Author(s):

ChenHan Liao ◽

Na Helian ◽

Sining Wu ◽

Mamunur M. Rashid

Keyword(s):

Decision Tree ◽

The Other ◽

Resource Usage ◽

Simulation Environment ◽

Data Grids ◽

Access Latency ◽

Replication Strategy ◽

Network Usage ◽

File Replication ◽

Effective Network

Most replication methods either monitor the popularity of files or use complicated functions to calculate the overall cost of whether or not a replication decision or a deletion decision should be issued. However, once the replication decision is issued, the popularity of the files is changed and may have already impacted access latency and resource usage. This article proposes a decision-tree-based predictive file replication strategy that forecasts files’ future popularity based on their characteristics on the Grids. The proposed strategy has shown superb performance in terms of mean job time and effective network usage compared with the other two replication strategies, LRU and Economic under OptorSim simulation environment.

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Stream Dependent Caching

Multimedia Information Storage and Retrieval ◽

10.4018/978-1-59904-225-1.ch023 ◽

2011 ◽

pp. 341-367

Author(s):

Phillip K.C. Tse

Keyword(s):

The Internet ◽

Cache Replacement ◽

Storage Devices ◽

Access Latency ◽

Remote Storage

Caching has been successfully implemented on the Internet to reduce workload on the content server and the Internet. We have seen in the last chapter how the cache replacement methods are adapted for multimedia objects in memory caching. In this chapter, we shall show how the caching is tailored to provide better performance for continuous request streams. Even though caching reduces the access latency when there are cache hits, there are chances that cache misses occur. When cache misses occur, the request stream is sent through the network to the remote storage devices. The requests are then served at the remote storage devices. The requested multimedia objects are retrieved from the storage devices, delivered through the network to the client. The cache content will also be modified to store the accessed object.

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Time Slicing Method

Multimedia Information Storage and Retrieval ◽

10.4018/978-1-59904-225-1.ch018 ◽

2011 ◽

pp. 272-279

Author(s):

Phillip K.C. Tse

Keyword(s):

High Throughput ◽

Storage Capacity ◽

Low Cost ◽

Storage Devices ◽

Access Latency ◽

Tertiary Storage ◽

Start Up ◽

Slicing Method ◽

Time Slicing

Tertiary storage devices provide huge storage capacity at low cost. Multimedia objects stored on the tertiary storage devices are accessed with high latency. Despite the high access latency, some tertiary storage devices are able to deliver data at high throughput. The time slicing method is designed to reduce the start-up latency in accessing multimedia objects from tertiary storage devices. The start-up latency is lowered by reducing the amount of data being migrated in stage one of the staging method being described in the last chapter. In order to support the time-slicing method, the tertiary storage devices should have the ability to deliver data at high throughput. The tertiary storage devices that cannot deliver data at sufficiently high throughput; the start-up latency cannot be reduced.

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