Static and adaptive data replication algorithms for fast information access in large distributed systems

Loukopoulos, Thanasis; Ahmad, Ishfaq

doi:10.1109/icdcs.2000.840950

Cited by 45 publications

(40 citation statements)

References 16 publications

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“…Path between peer 1 P and 2 P is direct of one hop count distance and path between peer 1 P to 4 P is of two hop count distance as shown in Fig. 2.…”

Section: Improved Hierarchical Quorum Consensus (Ihqc) Schemementioning

confidence: 99%

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Self Organized Replica Overlay Scheme for P2P Networks

Bhushan¹,

Dave²,

Patel³

2012

IJCNIS

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-Peer-to-Peer (P2P) systems are widely used for data sharing applications in an autonomous and decentralized mode. P2P systems are suitable for largescale distributed environments in which nodes can share resources other than data such as computing power, memory and network bandwidth. Some of important parameters that affect the performance of P2P systems are peer availability, data availability, network overhead, overlay structure, churn rate, and data access time. In this paper a self organized replica overlay scheme "Improved Hierarchical Quorum Consensus" (IHQC) for P2P systems is proposed. This scheme organizes replicas in a Self Organized Hierarchical Logical Structure (SOHLS) that has special properties. The scheme improves performance of the system by reducing search time to form read/write quorums, reducing probability of accessing stale data, improving degree of intersection among consecutive quorums and reducing network overhead. This scheme is highly fault tolerant (tolerate up to 1 n  faults) due to replication of data and inherits the best property of Read-One-Write-All (ROWA) protocol in a dynamic environment of P2P network. The architecture for IHQC is also proposed for implementing the scheme that supports improved performance of P2P systems. This scheme also maximizes the degree of intersection set of read and write quorums; hence, having higher probability to get updated data as compared to all other schemes. The mathematical correctness of the scheme is also presented in the paper. The results of simulation study of the proposed scheme also support and verify its better performance than Random and Hierarchical Quorum Scheme.

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“…Path between peer 1 P and 2 P is direct of one hop count distance and path between peer 1 P to 4 P is of two hop count distance as shown in Fig. 2.…”

Section: Improved Hierarchical Quorum Consensus (Ihqc) Schemementioning

confidence: 99%

“…[1][2] [3]. P2P systems provide an environment that overcomes limitations of the client/server based systems by avoiding bottleneck of scalability [4]. This advantage enables P2P systems to perform complex tasks with relatively low cost and without any need of powerful servers.…”

Section: Introductionmentioning

confidence: 99%

Self Organized Replica Overlay Scheme for P2P Networks

Bhushan¹,

Dave²,

Patel³

2012

IJCNIS

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“…Many previous research projects assumed that access patterns are known and remain unchanged. Some solutions for dynamic environments were proposed in [21,4,39]. A complete survey on models for FAP in computer network systems can be found in [13].…”

Section: Related Workmentioning

confidence: 99%

Document replication and distribution in extensible geographically distributed web servers

Zhuo¹,

Wang²,

Lau³

2003

Journal of Parallel and Distributed Computing

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A geographically distributed web server (GDWS) system, consisting of multiple server nodes interconnected by a MAN or a WAN, can achieve better efficiency in handling the ever-increasing web requests than centralized web servers because of the proximity of server nodes to clients. It is also more scalable since the throughput will not be limited by available bandwidth connecting to a central server. The key research issue in the design of GDWS is how to replicate and distribute the documents of a website among the server nodes. This paper proposes a density-based replication scheme and applies it to our proposed Extensible GDWS (EGDWS) architecture. Its document distribution scheme supports partial replication targeting only at hot objects among the documents. To distribute the replicas generated via the density-based replication scheme, we propose four different document distribution algorithms: Greedy-cost, Maximal-density, Greedypenalty, and Proximity-aware. A proximity-based routing mechanism is designed to incorporate these algorithms for achieving better web server performance in a WAN environment. Simulation results show that our document replication and distribution algorithms achieve better response times and load balancing than existing dynamic schemes. To further reduce user's response time, we propose two document grouping algorithms that can cut down on the request redirection overheads.

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“…Previously, the replica placement has been defined as a file assignment problem (FAP) [10,17], which aims to optimize a performance parameter (e.g., file transfer cost or response time) of a network system while satisfying the storage capacity constraint. Eswaran [11] has proved that the FAP is an NP-complete problem.…”

Section: Related Workmentioning

confidence: 99%

“…Let the total expected workload for SL sites be λ (lines [12][13][14][15][16][17][18][19]. Then, the ideal request rate for a site in SL is…”

Section: Algorithm 1 Dataplacementmentioning

confidence: 99%