A MINIMUM-PROCESS COORDINATED CHECKPOINTING PROTOCOL FOR MOBILE COMPUTING SYSTEMS

2008 ◽  
Vol 19 (04) ◽  
pp. 1015-1038 ◽  
Author(s):  
SUNIL KUMAR GUPTA ◽  
R. K. CHAUHAN ◽  
PARVEEN KUMAR
Keyword(s):  
Distributed Systems ◽  
Wireless Channels ◽  
Mobile Nodes ◽  
High Failure Rate ◽  
Computing Systems ◽  
Battery Power ◽  
The Status ◽  
Minimum Number ◽  
Status Information ◽  
Coordinated Checkpointing

Checkpoint is a designated place in a program at which normal process is interrupted specifically to preserve the status information necessary to allow resumption of processing at a later time. A checkpoint algorithm for mobile distributed systems needs to handle many new issues like: mobility, low bandwidth of wireless channels, lack of stable storage on mobile nodes, disconnections, limited battery power and high failure rate of mobile nodes. These issues make traditional checkpointing techniques unsuitable for such environments. Minimum-process coordinated checkpointing is an attractive approach to introduce fault tolerance in mobile distributed systems transparently. This approach is domino-free, requires at most two checkpoints of a process on stable storage, and forces only a minimum number of processes to checkpoint. But, it requires extra synchronization messages, blocking of the underlying computation or taking some useless checkpoints. In this paper, we design a minimum-process checkpointing algorithm for mobile distributed systems, where no useless checkpoint is taken. We reduce the blocking of processes by allowing the processes to do their normal computations, send messages and receive selective messages during their blocking period.

scholarly journals Effectual Non-Intrusive Minimum-Process Synchronous Checkpointing Protocol for Mobile Distributed Systems

2021 ◽  
pp. 325-331
Author(s):  
Raman Kumar ◽  
Er Jyoti Arora
Keyword(s):  
Distributed Systems ◽  
Communication Complexity ◽  
Optimization Technique ◽  
Mobile Systems ◽  
Global State ◽  
Mobile Nodes ◽  
Computing Systems ◽  
Mobile Hosts ◽  
Minimum Number ◽  
The Cost

While dealing with Mobile Distributed systems, we come across some issues like: mobility, low bandwidth of wireless channels and dearth of stable storage on mobile nodes, disconnections, inadequate battery power and high failure rate of mobile nodes. Minimum-process coordinated checkpointing is considered an attractive methodology to introduce fault tolerance in mobile systems transparently. In this paper, we propose a non-blocking coordinated global state compilation algorithm for mobile computing systems, which requires only a minimum number of processes to take permanent recovery points. We reduce the communication complexity as compared to the Cao-Singhal algorithm [4], while keeping the number of useless recovery points unchanged. Finally, the paper presents an optimization technique, which significantly reduces the number of useless recovery points at the cost of minor increase in the communication complexity. In coordinated global state compilation, if a single process fails to take its tentative recovery point; all the recovery point effort is aborted. We try to reduce this effort by taking soft recovery points in the first phase at Mobile Hosts.

scholarly journals A Low-Cost Hybrid Coordinated Checkpointing Protocol for Mobile Distributed Systems

2008 ◽  
Vol 4 (1) ◽  
pp. 13-32 ◽  
Author(s):  
Parveen Kumar
Keyword(s):  
Distributed Systems ◽  
Low Cost ◽  
Fixed Number ◽  
Mobile Nodes ◽  
Battery Power ◽  
Coordinated Checkpointing ◽  
The Cost ◽  
Coordinated Checkpoint ◽  
Low Activity ◽  
Blocking Algorithm

Mobile distributed systems raise new issues such as mobility, low bandwidth of wireless channels, disconnections, limited battery power and lack of reliable stable storage on mobile nodes. In minimum-process coordinated checkpointing, some processes may not checkpoint for several checkpoint initiations. In the case of a recovery after a fault, such processes may rollback to far earlier checkpointed state and thus may cause greater loss of computation. In all-process coordinated checkpointing, the recovery line is advanced for all processes but the checkpointing overhead may be exceedingly high. To optimize both matrices, the checkpointing overhead and the loss of computation on recovery, we propose a hybrid checkpointing algorithm, wherein an all-process coordinated checkpoint is taken after the execution of minimum-process coordinated checkpointing algorithm for a fixed number of times. Thus, the Mobile nodes with low activity or in doze mode operation may not be disturbed in the case of minimum-process checkpointing and the recovery line is advanced for each process after an all-process checkpoint. Additionally, we try to minimize the information piggybacked onto each computation message. For minimum-process checkpointing, we design a blocking algorithm, where no useless checkpoints are taken and an effort has been made to optimize the blocking of processes. We propose to delay selective messages at the receiver end. By doing so, processes are allowed to perform their normal computation, send messages and partially receive them during their blocking period. The proposed minimum-process blocking algorithm forces zero useless checkpoints at the cost of very small blocking.

Soft-Checkpointing Based Hybrid Synchronous Checkpointing Protocol for Mobile Distributed Systems

2011 ◽  
Vol 2 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Parveen Kumar ◽  
Rachit Garg
Keyword(s):  
Distributed Systems ◽  
Fault Tolerance ◽  
Wireless Channels ◽  
Probabilistic Approach ◽  
Fixed Number ◽  
Mobile Host ◽  
Single Process ◽  
Coordinated Checkpointing ◽  
Coordinated Checkpoint

Minimum-process coordinated checkpointing is a suitable approach to introduce fault tolerance in mobile distributed systems transparently. In order to balance the checkpointing overhead and the loss of computation on recovery, the authors propose a hybrid checkpointing algorithm, wherein an all-process coordinated checkpoint is taken after the execution of minimum-process coordinated checkpointing algorithm for a fixed number of times. In coordinated checkpointing, if a single process fails to take its checkpoint; all the checkpointing effort goes waste, because, each process has to abort its tentative checkpoint. In order to take the tentative checkpoint, an MH (Mobile Host) needs to transfer large checkpoint data to its local MSS over wireless channels. In this regard, the authors propose that in the first phase, all concerned MHs will take soft checkpoint only. Soft checkpoint is similar to mutable checkpoint. In this case, if some process fails to take checkpoint in the first phase, then MHs need to abort their soft checkpoints only. The effort of taking a soft checkpoint is negligibly small as compared to the tentative one. In the minimum-process coordinated checkpointing algorithm, an effort has been made to minimize the number of useless checkpoints and blocking of processes using probabilistic approach.

Soft-Checkpointing Based Hybrid Synchronous Checkpointing Protocol for Mobile Distributed Systems

2012 ◽  
pp. 806-818
Author(s):  
Parveen Kumar ◽  
Rachit Garg
Keyword(s):  
Distributed Systems ◽  
Fault Tolerance ◽  
Wireless Channels ◽  
Probabilistic Approach ◽  
Fixed Number ◽  
Mobile Host ◽  
Single Process ◽  
Coordinated Checkpointing ◽  
Coordinated Checkpoint

Minimum-process coordinated checkpointing is a suitable approach to introduce fault tolerance in mobile distributed systems transparently. In order to balance the checkpointing overhead and the loss of computation on recovery, the authors propose a hybrid checkpointing algorithm, wherein an all-process coordinated checkpoint is taken after the execution of minimum-process coordinated checkpointing algorithm for a fixed number of times. In coordinated checkpointing, if a single process fails to take its checkpoint; all the checkpointing effort goes waste, because, each process has to abort its tentative checkpoint. In order to take the tentative checkpoint, an MH (Mobile Host) needs to transfer large checkpoint data to its local MSS over wireless channels. In this regard, the authors propose that in the first phase, all concerned MHs will take soft checkpoint only. Soft checkpoint is similar to mutable checkpoint. In this case, if some process fails to take checkpoint in the first phase, then MHs need to abort their soft checkpoints only. The effort of taking a soft checkpoint is negligibly small as compared to the tentative one. In the minimum-process coordinated checkpointing algorithm, an effort has been made to minimize the number of useless checkpoints and blocking of processes using probabilistic approach.

Soft-Checkpointing Based Hybrid Synchronous Checkpointing Protocol for Mobile Distributed Systems

2012 ◽  
pp. 87-100
Author(s):  
Parveen Kumar ◽  
Rachit Garg
Keyword(s):  
Distributed Systems ◽  
Fault Tolerance ◽  
Wireless Channels ◽  
Probabilistic Approach ◽  
Fixed Number ◽  
Mobile Host ◽  
Single Process ◽  
Coordinated Checkpointing ◽  
Coordinated Checkpoint

Minimum-process coordinated checkpointing is a suitable approach to introduce fault tolerance in mobile distributed systems transparently. In order to balance the checkpointing overhead and the loss of computation on recovery, the authors propose a hybrid checkpointing algorithm, wherein an all-process coordinated checkpoint is taken after the execution of minimum-process coordinated checkpointing algorithm for a fixed number of times. In coordinated checkpointing, if a single process fails to take its checkpoint; all the checkpointing effort goes waste, because, each process has to abort its tentative checkpoint. In order to take the tentative checkpoint, an MH (Mobile Host) needs to transfer large checkpoint data to its local MSS over wireless channels. In this regard, the authors propose that in the first phase, all concerned MHs will take soft checkpoint only. Soft checkpoint is similar to mutable checkpoint. In this case, if some process fails to take checkpoint in the first phase, then MHs need to abort their soft checkpoints only. The effort of taking a soft checkpoint is negligibly small as compared to the tentative one. In the minimum-process coordinated checkpointing algorithm, an effort has been made to minimize the number of useless checkpoints and blocking of processes using probabilistic approach.

scholarly journals Estimation of the Number of General Anesthesia Cases Based on a Series of Nationwide Surveys on Twitter during COVID-19 Pandemic in Japan: A Statistical Analysis

Medicina ◽  
2021 ◽  
Vol 57 (2) ◽  
pp. 153
Author(s):  
Yosuke Fujii ◽  
Hiroki Daijo ◽  
Kiichi Hirota
Keyword(s):  
General Anesthesia ◽  
Japanese Society ◽  
Care Delivery ◽  
Japanese Government ◽  
State Of Emergency ◽  
Social Network Service ◽  
The Social ◽  
Public Data ◽  
The Status ◽  
Minimum Number

Background and objectives: Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread to more than 200 countries. In light of this situation, the Japanese Government declared a state of emergency in seven regions of Japan on 7 April 2020 under the provisions of the law. The medical care delivery system has been under pressure. Although various surgical societies have published guidelines on which to base their surgical decisions, it is not clear how general anesthesia has been performed and will be performed in Japan. Materials and Methods: One of the services provided by the social network service Twitter is a voting function—Twitter Polls—through which anonymous surveys were conducted. We analyzed the results of a series of surveys 17 times over 22 weeks on Twitter on the status of operating restrictions using quadratic programming to solve the mathematical optimizing problem, and public data provided by the Japanese Government were used to estimate the current changes in the number of general anesthesia performed in Japan. Results: The minimum number of general anesthesia cases per week was estimated at 67.1% compared to 2015 on 27 April 2020. The timeseries trend was compatible with the results reported by the Japanese Society of Anesthesiologists (correlation coefficient r = 0.69, p < 0.001). Conclusions: The number of general anesthesia was reduced up to two-thirds during the pandemic of COVID-19 in Japan and was successfully quantitatively estimated using a quick questionnaire on Twitter.

scholarly journals The influence application of Information Technology and Competence on Employee Productivity through Job Satisfaction in the Civil Apparatus at Hasanuddin University

2020 ◽  
Vol 2 (3) ◽  
pp. 92-99
Author(s):  
Muhammad Erfan ◽  
Mahlia Muis ◽  
Andi Ratna Sari Dewi
Keyword(s):  
Job Satisfaction ◽  
Information Technology ◽  
Sampling Method ◽  
Work Productivity ◽  
Sampling Technique ◽  
Simple Random Sampling ◽  
Measurement Scale ◽  
Employee Productivity ◽  
The Status ◽  
Minimum Number

This study aims to analyze (i) the effect of information technology variables on job satisfaction; (ii) the effect of competency variables on job satisfaction; (iii) the effect of information technology variables on work productivity; (iv) the effect of competency variables on work productivity; (v) the effect of job satisfaction variables on work productivity; (vi) the influence of information technology variables on work productivity through job satisfaction variables; and (vii) the effect of competency variables on work productivity through job satisfaction variables. The quantitative approach is used to test and analyze the factors that influence job satisfaction and work productivity. Research location at Hasanuddin University, Makassar City. The population in this study were Unhas employees with the status of ASN (State Civil Apparatus) as many as 935 people. The sampling method uses probability sampling with a simple random sampling technique. Withdrawing the number of samples using the Slovin formula, which produces 90 people as a minimum number. Data collection techniques using a questionnaire with a measurement scale used is a Likert scale with five components. Data analysis techniques in this study used path analysis. The results showed that information technology and competency variables significantly influence job satisfaction and work productivity. Information technology and competence have a significant effect on work productivity through job satisfaction variables. All hypotheses are accepted and supported by previous research.

scholarly journals Equity and Reward Crowdfunding: A Multiple Signal Analysis

2020 ◽  
Vol 12 (3) ◽  
pp. 30
Author(s):  
Ciro Troise ◽  
Mario Tani ◽  
Ornella Papaluca
Keyword(s):  
Human Capital ◽  
Signal Analysis ◽  
Multiple Signal ◽  
The Status ◽  
Status Information ◽  
Equity Model ◽  
Start Ups

This paper aims to analyse the success signals of initiatives through equity and reward crowdfunding, the two typologies most used by start-ups and SMEs. This article discusses and compares these two models, highlighting the main differences and similarities, by analyzing the factors that influence the success of initiatives through crowdfunding, measured both in terms of amount of funding raised and number of investors that funded the initiatives. The focus is on three sets of signals, venture quality (human capital, information about the establishment and the status of the initiatives), the level of information the company provides to reduce the degree of uncertainty and campaign quality. Using two distinct datasets, one of 235 equity-model initiatives and one of 274 reward-model initiatives, in both cases analyzing projects that have reached (or exceeded) the funding goal, it turns out that venture quality affects in both types, though distinctly, in particular in the reward model play an important role the awards, in addition to the rounds and the tutors (the latter two also present in the equity model), which constitute the status information of the company, while the information about the establishment and the human capital affects only the equity model. Equally for the equity model affects the level of information to reduce uncertainty, while campaign quality in both types seems to have a very slight impact.

Effective Routing in Mobile Ad-hoc Networks With Power and End-to-End Delay Optimization

2018 ◽  
pp. 206-243 ◽  
Author(s):  
Mamata Rath
Keyword(s):  
Power Efficiency ◽  
Ad Hoc ◽  
Mobile Ad Hoc Network ◽  
Industrial Applications ◽  
Technology Support ◽  
Mobile Nodes ◽  
Battery Power ◽  
Minimum Power Consumption ◽  
Mobile Ad Hoc ◽  
Hoc Networks

Mobile ad-hoc network (MANET) has always been a challenging and pioneering wireless network providing magnificent technology support starting from everyday life to disaster and critical environment. In industrial applications and most of the real-world solicitations, the MANET technology greatly suffers due to practical challenges faced by the network, power deficiency, and dynamic topology change being the prominent factors. Many cross-layer platforms supporting real-time applications have been developed by many researchers with the basic intention being maximum utilization of resources in the resource constrained environment of MANET, minimum power consumption using limited residual battery power of the highly transferable mobile nodes. This chapter presents the design of an optimized network layer protocol with delay management and power efficiency.

Security Issues in Distributed Computing System Models

2017 ◽  
pp. 211-259 ◽  
Author(s):  
Ghada Farouk Elkabbany ◽  
Mohamed Rasslan
Keyword(s):  
Distributed Systems ◽  
Distributed Computing ◽  
Computing System ◽  
Computing Environment ◽  
Distributed Computing Systems ◽  
Computing Systems ◽  
Research Directions ◽  
System Models ◽  
Security Issues ◽  
Systems Security

Distributed computing systems allow homogenous/heterogeneous computers and workstations to act as a computing environment. In this environment, users can uniformly access local and remote resources in order to run processes. Users are not aware of which computers their processes are running on. This might pose some complicated security problems. This chapter provides a security review of distributed systems. It begins with a survey about different and diverse definitions of distributed computing systems in the literature. Different systems are discussed with emphasize on the most recent. Finally, different aspects of distributed systems security and prominent research directions are explored.

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