Neighbor-Replica Distribution Technique Model for Availability Prediction in Distributed Interdependent Environment

2012 ◽  
Vol 2 (3) ◽  
pp. 98-109
Author(s):  
Ahmad Shukri Mohd Noor ◽  
Tutut Herawan ◽  
Mustafa Mat Deris
Keyword(s):  
Distributed Systems ◽  
Fault Tolerance ◽  
Prediction Model ◽  
Large Scale ◽  
Extended Period ◽  
High Availability ◽  
Performance Data ◽  
Online System ◽  
Future Expectation ◽  
Replication Technique

High availability is important for large scale distributed systems. Replication provides effective ways to enhance performance, high availability and fault tolerance in distributed systems. An efficient and effective replication technique is the key to improve the availability performance. Data and processes can be replicated for failures recovery. There are currently projects successfully implemented in two-replica distribution technique (TRDT) or primary–backup technique. However, these projects have their weaknesses of increasing cost overhead and inherit irrecoverable scenarios from TRDT such as double faults when both copies of replicated components are damaged. The authors propose the Neighbor Replica Distributed Technique (NRDT) availability prediction model. Focusing on improving high availability in which it predicts future expectation of interdependent server’s availability in a distributed online system over an extended period of time. The results and discussion are explored further in the article.

scholarly journals State of Art Survey for Fault Tolerance Feasibility in Distributed Systems

2021 ◽  
pp. 19-34
Author(s):  
Arshad A. Hussein ◽  
Adel AL-zebari ◽  
Naaman Omar ◽  
Karwan Jameel Merceedi ◽  
Abdulraheem Jamil Ahmed ◽  
...  
Keyword(s):  
Distributed Systems ◽  
Fault Tolerance ◽  
Distributed System ◽  
Recent Literature ◽  
High Availability ◽  
Daily Activities ◽  
Service Availability ◽  
System Failures ◽  
Distributed Services ◽  
Use Of Technology

The use of technology has grown dramatically, and computer systems are now interconnected via various communication mediums. The use of distributed systems (DS) in our daily activities has only gotten better with data distributions. This is due to the fact that distributed systems allow nodes to arrange and share their resources across linked systems or devices, allowing humans to be integrated with geographically spread computer capacity. Due to multiple system failures at multiple failure points, distributed systems may result in a lack of service availability. to avoid multiple system failures at multiple failure points by using fault tolerance (FT) techniques in distributed systems to ensure replication, high redundancy, and high availability of distributed services. In this paper shows ease fault tolerance systems, its requirements, and explain about distributed system. Also, discuss distributed system architecture; furthermore, explain used techniques of fault tolerance, in additional that review some recent literature on fault tolerance in distributed systems and finally, discuss and compare the fault tolerance literature.

Fault Tolerance

2010 ◽  
pp. 168-193
Author(s):  
Valentin Cristea ◽  
Ciprian Dobre ◽  
Corina Stratan ◽  
Florin Pop
Keyword(s):  
Distributed Systems ◽  
Fault Tolerance ◽  
Large Scale ◽  
Fault Tolerant ◽  
Distributed Applications ◽  
Future Trends ◽  
Distributed Architectures ◽  
P2p Systems ◽  
Geographically Distributed ◽  
Commercial Applications

The domains of usage of large scale distributed systems have been extending during the past years from scientific to commercial applications. Together with the extension of the application domains, new requirements have emerged for large scale distributed systems. Among these requirements, fault tolerance is needed by more and more modern distributed applications, not only by the critical ones. In this chapter we analyze current existing work in enabling fault tolerance in case of large scale distributed systems, presenting specific problem, existing solution, as well as several future trends. The characteristics of these systems pose problems to ensuring fault tolerance especially because of their complexity, involving many resources and users geographically distributed, because of the volatility of resources that are available only for limited amounts of time, and because of the constraints imposed by the applications and resource owners. A general fault tolerant architecture should, at a minimum, be comprised of at least a mechanism to detect failures and a component capable to recover and handle the detected failures, usually using some form of a replication mechanism. In this chapter we analyzed existing fault tolerance implementations, as well as solutions adopted in real world large scale distributed systems. We analyzed the fault tolerance architectures being proposed for particular distributed architectures, such as Grid or P2P systems.

Theory and Practice of Fault Tolerance in Distributed Systems.

1987 ◽  
Author(s):  
K. M. Chandy ◽  
J. Misra
Keyword(s):  
Distributed Systems ◽  
Fault Tolerance ◽  
Theory And Practice

Bioactivity Prediction Based on Matched Molecular Pair and Matched Molecular Series Methods

2020 ◽  
Vol 26 (33) ◽  
pp. 4195-4205
Author(s):  
Xiaoyu Ding ◽  
Chen Cui ◽  
Dingyan Wang ◽  
Jihui Zhao ◽  
Mingyue Zheng ◽  
...  
Keyword(s):  
Prediction Model ◽  
Large Scale ◽  
Prediction Models ◽  
Predictive Accuracy ◽  
Lead Optimization ◽  
Consensus Method ◽  
Molecular Pair ◽  
Bioactivity Prediction ◽  
Compound Synthesis ◽  
Consensus Modeling

Background: Enhancing a compound’s biological activity is the central task for lead optimization in small molecules drug discovery. However, it is laborious to perform many iterative rounds of compound synthesis and bioactivity tests. To address the issue, it is highly demanding to develop high quality in silico bioactivity prediction approaches, to prioritize such more active compound derivatives and reduce the trial-and-error process. Methods: Two kinds of bioactivity prediction models based on a large-scale structure-activity relationship (SAR) database were constructed. The first one is based on the similarity of substituents and realized by matched molecular pair analysis, including SA, SA_BR, SR, and SR_BR. The second one is based on SAR transferability and realized by matched molecular series analysis, including Single MMS pair, Full MMS series, and Multi single MMS pairs. Moreover, we also defined the application domain of models by using the distance-based threshold. Results: Among seven individual models, Multi single MMS pairs bioactivity prediction model showed the best performance (R2 = 0.828, MAE = 0.406, RMSE = 0.591), and the baseline model (SA) produced the most lower prediction accuracy (R2 = 0.798, MAE = 0.446, RMSE = 0.637). The predictive accuracy could further be improved by consensus modeling (R2 = 0.842, MAE = 0.397 and RMSE = 0.563). Conclusion: An accurate prediction model for bioactivity was built with a consensus method, which was superior to all individual models. Our model should be a valuable tool for lead optimization.

Workshop on large-scale distributed systems for information retrieval

2007 ◽  
Vol 41 (2) ◽  
pp. 83-88
Author(s):  
Flavio P. Junqueira ◽  
Vassilis Plachouras ◽  
Fabrizio Silvestri ◽  
Ivana Podnar
Keyword(s):  
Information Retrieval ◽  
Distributed Systems ◽  
Large Scale
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