THREE DIMENSIONAL GRID STRUCTURE FOR EFFICIENT ACCESS OF REPLICATED DATA

2001 ◽  
Vol 02 (03) ◽  
pp. 317-329 ◽  
Author(s):  
MUSTAFA MAT DERIS ◽  
ALI MAMAT ◽  
PUA CHAI SENG ◽  
MOHD YAZID SAMAN
Keyword(s):  
Distributed System ◽  
Three Dimensional ◽  
Data Replication ◽  
High Availability ◽  
Communication Cost ◽  
Data Availability ◽  
Grid Structure ◽  
Communication Costs ◽  
Replicated Data ◽  
Efficient Access

This article addresses the performance of data replication protocol in terms of data availability and communication costs. Specifically, we present a new protocol called Three Dimensional Grid Structure (TDGS) protocol, to manage data replication in distributed system. The protocol provides high availability for read and write operations with limited fault-tolerance at low communication cost. With TDGS protocol, a read operation is limited to two data copies, while a write operation is required with minimal number of copies. In comparison to other protocols. TDGS requires lower communication cost for an operation, while providing higher data availability.

scholarly journals Secure Routing in Manet Using Synchronization and Data Authencity

2014 ◽  
Vol 14 (2) ◽  
pp. 24-30 ◽  
Author(s):  
Gundala Swathi ◽  
R. Saravanan
Keyword(s):  
Time Synchronization ◽  
Data Replication ◽  
Secure Routing ◽  
Data Availability ◽  
Mobile Adhoc Networks ◽  
Adverse Conditions ◽  
Synchronization Algorithm ◽  
Adhoc Networks ◽  
Secure Transmission

Abstract In recent years synchronization plays a major issue for secure transmission in mobile adhoc networks. When an attacker modifies the time synchronization algorithm, the nodes will have faulty estimates of other nodes location, leading to chaos. While transmitting under these adverse conditions, packets might be lost or might be sent to wrong locations. Data replication and data diffusion are two methods which are used to solve the problem of data availability. In this paper we propose an algorithm for secure multi hop transmission used for external attacks.

scholarly journals Secure Data Replication Management Scheme with Better Data Accessibility

2019 ◽  
Vol 8 (12) ◽  
pp. 4484-4488
Keyword(s):  
Cloud Computing ◽  
Data Replication ◽  
Data Availability ◽  
Computing Technology ◽  
Data Accessibility ◽  
Access Frequency ◽  
Management Scheme ◽  
Replica Allocation ◽  
Cloud Server ◽  
Secure Data

Cloud computing technology has gained substantial research interest, due to its remarkable range of services. The major concerns of cloud computing are availability and security. Several security algorithms are presented in the literature for achieving better security and the data availability is increased by utilizing data replicas. However, creation of replicas for all the data is unnecessary and consumes more storage space. Considering this issue, this article presents a Secure Data Replication Management Scheme (SDRMS), which creates replicas by considering the access frequency of the data and the replicas are loaded onto the cloud server by considering the current load of it. This idea balances the load of the cloud server. All the replicas are organized in a tree like structure and the replicas with maximum hit ratio are placed on the first level of the tree to ensure better data accessibility. The performance of the work is satisfactory in terms of data accessibility, storage exploitation, replica allocation and retrieval time.

scholarly journals Novelty circular neighboring technique using reactive fault tolerance method

2019 ◽  
Vol 9 (6) ◽  
pp. 5211
Author(s):  
Ahmad Shukri Mohd Noor ◽  
Nur Farhah Mat Zian ◽  
Noor Hafhizah Abd Rahim ◽  
Rabiei Mamat ◽  
Wan Nur Amira Wan Azman
Keyword(s):  
Fault Tolerance ◽  
Data Replication ◽  
Data Availability ◽  
Complex Environment ◽  
Tolerance Mechanism ◽  
System Availability ◽  
Replication Technique ◽  
The Right ◽  
Tolerance Method ◽  
Reactive Method

The availability of the data in a distributed system can be increase by implementing fault tolerance mechanism in the system. Reactive method in fault tolerance mechanism deals with restarting the failed services, placing redundant copies of data in multiple nodes across network, in other words data replication and migrating the data for recovery. Even if the idea of data replication is solid, the challenge is to choose the right replication technique that able to provide better data availability as well as consistency that involves read and write operations on the redundant copies. Circular Neighboring Replication (CNR) technique exploits neighboring policy in replicating the data items in the system performs well with regards to lower copies needed to maintain the system availability at the highest. In a performance analysis with existing techniques, results show that CNR improves system availability by average 37% by offering only two replicas needed to maintain data availability and consistency. The study demonstrates the possibility of the proposed technique and the potential of deploying in larger and complex environment.

scholarly journals A four-phase data replication algorithm for data grid

2015 ◽  
Vol 4 (1) ◽  
pp. 163 ◽  
Author(s):  
Alireza Saleh ◽  
Reza Javidan ◽  
Mohammad Taghi FatehiKhajeh
Keyword(s):  
Large Scale ◽  
Data Replication ◽  
Data Grid ◽  
Data Availability ◽  
Access Time ◽  
File Transfer ◽  
System Availability ◽  
Large Scale Data ◽  
Effective Network ◽  
Average Access Time

<p>Nowadays, scientific applications generate a huge amount of data in terabytes or petabytes. Data grids currently proposed solutions to large scale data management problems including efficient file transfer and replication. Data is typically replicated in a Data Grid to improve the job response time and data availability. A reasonable number and right locations for replicas has become a challenge in the Data Grid. In this paper, a four-phase dynamic data replication algorithm based on Temporal and Geographical locality is proposed. It includes: 1) evaluating and identifying the popular data and triggering a replication operation when the popularity data passes a dynamic threshold; 2) analyzing and modeling the relationship between system availability and the number of replicas, and calculating a suitable number of new replicas; 3) evaluating and identifying the popular data in each site, and placing replicas among them; 4) removing files with least cost of average access time when encountering insufficient space for replication. The algorithm was tested using a grid simulator, OptorSim developed by European Data Grid Projects. The simulation results show that the proposed algorithm has better performance in comparison with other algorithms in terms of job execution time, effective network usage and percentage of storage filled.</p>

scholarly journals Multiobjective Glowworm Swarm Optimization-Based Dynamic Replication Algorithm for Real-Time Distributed Databases

2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Saadi Hamad Thalij ◽  
Veli Hakkoymaz
Keyword(s):  
Real Time ◽  
Large Scale ◽  
Distributed Databases ◽  
Data Replication ◽  
Data Availability ◽  
Access Time ◽  
Swarm Optimization ◽  
Dynamic Data ◽  
Glowworm Swarm Optimization ◽  
Dynamic Data Replication

Distributed systems offer resources to be accessed geographically for large-scale data requests of different users. In many cases, replication of the vital data files and storing their replica in multiple locations accessible to the requesting clients is vital in improving the data availability, reliability, security, and reduction of the execution time. It is important that real-time distributed databases maintain the consistency constraints and also guarantee the time constraints required by the client requests. However, when the size of the distributed system increases, the user access time also tends to increase, which in turn increases the vitality of the replica placement. Thus, the primary issues that emerge are deciding upon an optimal replication number and identifying perfect locations to store the replicated data. These open challenges have been considered in this study, which turns to develop a dynamic data replication algorithm for real-time distributed databases using a multiobjective glowworm swarm optimization (MGSO) strategy. The proposed algorithm adapts the random patterns of the read-write requests and employs a dynamic window mechanism for replication. It also models the replica number and placement problem as a multiobjective optimization problem and utilizes MGSO for resolving it. The cost models are presented to ensure the time constraint satisfaction in servicing user requests. The performance of the MGSO dynamic data replication algorithm has been studied using competitive analysis, and the results show the efficiency of the proposed algorithm for the distributed databases.

scholarly journals Efficient Dynamic Replication Algorithm Using Agent for Data Grid

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Priyanka Vashisht ◽  
Rajesh Kumar ◽  
Anju Sharma
Keyword(s):  
Data Replication ◽  
Data Access ◽  
Data Grid ◽  
Data Availability ◽  
Access Time ◽  
Test Bed ◽  
Data Grids ◽  
Dynamic Replication ◽  
Data Files ◽  
Using Data

In data grids scientific and business applications produce huge volume of data which needs to be transferred among the distributed and heterogeneous nodes of data grids. Data replication provides a solution for managing data files efficiently in large grids. The data replication helps in enhancing the data availability which reduces the overall access time of the file. In this paper an algorithm, namely, EDRA using agents for data grid, has been proposed and implemented. EDRA consists of dynamic replication of hierarchical structure taken into account for the selection of best replica. Decision for selecting the best replica is based on scheduling parameters. The scheduling parameters are bandwidth, load gauge, and computing capacity of the node. The scheduling in data grid helps in reducing the data access time. The distribution of the load on the nodes of data grid is done evenly by considering scheduling parameters. EDRA is implemented using data grid simulator, namely, OptorSim. European Data Grid CMS test bed topology is used in this experiment. The simulation results are obtained by comparing BHR, LRU, No Replication, and EDRA. The result shows the efficiency of EDRA algorithm in terms of mean job execution time, network usage, and storage usage of node.

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