Replica Aware Reliable File Transfer Service for the Data Grid

Author(s):  
Yoonki Lee ◽  
Eunsung Kim ◽  
Heon Y. Yeom
Keyword(s):  
2013 ◽  
Vol 5 (1) ◽  
pp. 70-81 ◽  
Author(s):  
Mohammed K. Madi ◽  
Yuhanis Yusof ◽  
Suhaidi Hassan

Data Grid is an infrastructure that manages huge amount of data files, and provides intensive computational resources across geographically distributed collaboration. To increase resource availability and to ease resource sharing in such environment, there is a need for replication services. Data replication is one of the methods used to improve the performance of data access in distributed systems by replicating multiple copies of data files in the distributed sites. Replica placement mechanism is the process of identifying where to place copies of replicated data files in a Grid system. Existing work identifies the suitable sites based on number of requests and read cost of the required file. Such approaches consume large bandwidth and increases the computational time. The authors propose a replica placement strategy (RPS) that finds the best locations to store replicas based on four criteria, namely, 1) Read Cost, 2) File Transfer Time, 3) Sites’ Workload, and 4) Replication Sites. OptorSim is used to evaluate the performance of this replica placement strategy. The simulation results show that RPS requires less execution time and consumes less network usage compared to existing approaches of Simple Optimizer and LFU (Least Frequently Used).


2015 ◽  
Vol 4 (1) ◽  
pp. 163 ◽  
Author(s):  
Alireza Saleh ◽  
Reza Javidan ◽  
Mohammad Taghi FatehiKhajeh

<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>


Author(s):  
H. O. Colijn

Many labs today wish to transfer data between their EDS systems and their existing PCs and minicomputers. Our lab has implemented SpectraPlot, a low- cost PC-based system to allow offline examination and plotting of spectra. We adopted this system in order to make more efficient use of our microscopes and EDS consoles, to provide hardcopy output for an older EDS system, and to allow students to access their data after leaving the university.As shown in Fig. 1, we have three EDS systems (one of which is located in another building) which can store data on 8 inch RT-11 floppy disks. We transfer data from these systems to a DEC MINC computer using “SneakerNet”, which consists of putting on a pair of sneakers and running down the hall. We then use the Hermit file transfer program to download the data files with error checking from the MINC to the PC.


2020 ◽  
Author(s):  
Sasqia Ismi Aulia ◽  

This study aims to design a LAN network for data backup systems that are in accordance with certain aspects such as the selection of network design, network hardware, network transmission media, network connection devices, and network operating systems. Data is the most important thing for everyone, data can usually be reused even though it has not been used for some time, and therefore data storage is a serious problem that must be considered. Data on the server computer is very important to be maintained so that a backup process is needed on that data to another computer that is used as a backup in the event of damage to the hardware and software of the server computer. FTP is one of the solutions to the problems faced above,where FTP can be used to process the download and upload between the server and client computers. This design uses the Autobot system. The expected benefit in designing this LAN is that the existing network at SMP Negeri 6 Pekanbaru is not only used by employees and employees but can be used and enjoyed by teachers and students to access the internet anywhere as long as it is still within the scope of the SMP Negeri 6 area Pekanbaru.


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