The Experts below are selected from a list of 3000 Experts worldwide ranked by ideXlab platform
Yun Yang - One of the best experts on this subject based on the ideXlab platform.
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Adaptive Selection of Necessary and Sufficient Checkpoints for Dynamic Verification of Temporal Constraints in Grid Workflow Systems
2015Co-Authors: Jinjun Chen, Yun YangAbstract:In grid workflow systems, a Checkpoint Selection strategy is responsible for selecting Checkpoints for conducting temporal verification at the runtime execution stage. Existing representative check-point Selection strategies often select some unnecessary Checkpoints and omit some necessary ones because they cannot adapt to the dynamics and uncertainty of runtime activity completion duration. In this article, based on the dynamics and uncertainty of runtime activity completion duration, we develop a novel Checkpoint Selection strategy that can adaptively select not only necessary, but also sufficient Checkpoints. Specifically, we introduce a new concept of minimum time redundancy as a key reference parameter for Checkpoint Selection. An important feature of minimum time redun-dancy is that it can adapt to the dynamics and uncertainty of runtime activity completion duration. We develop a method on how to achieve minimum time redundancy dynamically along grid work-flow execution and investigate its relationships with temporal consistency. Based on the method and the relationships, we present our strategy and rigorously prove its necessity and sufficiency. The simulation evaluation further demonstrates experimentally such necessity and sufficiency an
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An Activity Completion Duration based Checkpoint Selection Strategy for Dynamic Verification of Fixed-time Constraints
2013Co-Authors: Jinjun Chen, Yun YangAbstract:In grid workflow systems, to verify temporal constraints efficiently at run-time execution stage, some Checkpoints are often selected so that we only need to conduct temporal verification at such Checkpoints rather than at all activity points. However, existing typical Checkpoint Selection strategies often ignore some necessary Checkpoints and select some unnecessary ones. This would eventually impact overall temporal verification effectiveness and efficiency. To improve such status, in this paper, we develop a new Checkpoint Selection strategy. Specifically, we first investigate the relationships between activity completion duration and the consistency of temporal constraints. Then, based on those relationships we present our new Checkpoint Selection strategy. Our new strategy can avoid the omission of necessary Checkpoints and the Selection of excess unnecessary Checkpoints. Consequently, it can achieve better temporal verification effectiveness and efficiency than the existing typical Checkpoint Selection strategies. The final comparison and quantitative evaluation further demonstrate this result. Key words: grid workflows, temporal constraints, Checkpoint Selection, temporal verification effectiveness, temporal verification efficienc
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selecting Checkpoints along the time line a novel temporal Checkpoint Selection strategy for monitoring a batch of parallel business processes
International Conference on Software Engineering, 2013Co-Authors: Xiao Liu, Yun Yang, Dahai Cao, Dong YuanAbstract:Nowadays, most business processes are running in a parallel, distributed and time-constrained manner. How to guarantee their on-time completion is a challenging issue. In the past few years, temporal Checkpoint Selection which selects a subset of workflow activities for verification of temporal consistency has been proved to be very successful in monitoring single, complex and large size scientific workflows. An intuitive approach is to apply those strategies to individual business processes. However, in such a case, the total number of Checkpoints will be enormous, namely the cost for system monitoring and exception handling could be excessive. To address such an issue, we propose a brand new idea which selects time points along the workflow execution time line as Checkpoints to monitor a batch of parallel business processes simultaneously instead of individually. Based on such an idea, a set of new definitions as well as a time-point based Checkpoint Selection strategy are presented in this paper. Our preliminary results demonstrate that it can achieve an order of magnitude reduction in the number of Checkpoints while maintaining satisfactory on-time completion rates compared with the state-of-the-art activity-point based Checkpoint Selection strategy.
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Temporal Violation Handling
Temporal QOS Management in Scientific Cloud Workflow Systems, 2012Co-Authors: Xiao Liu, Yun Yang, Jinjun ChenAbstract:Temporal violation handling is the key of the last component in our temporal framework for scientific cloud workflow systems. Clearly, whether a detected temporal violation can be recovered or not mainly depends on the performance of temporal violation handling strategies employed in the system. Meanwhile, since the time overheads and monetary cost for temporal violation handling strategies are usually much more expensive than that of its precedent steps such as Checkpoint Selection and temporal verification, cost-effective temporal violation handling strategies are required to be employed or designed to reduce the overall cost of the temporal framework.
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Forecasting Scientific Cloud Workflow Activity Duration Intervals
Temporal QOS Management in Scientific Cloud Workflow Systems, 2012Co-Authors: Xiao Liu, Yun Yang, Jinjun ChenAbstract:As discussed in Chapter 2, workflow activity duration is one of the basic elements in the temporal consistency model, and thus its accuracy is critical for the effectiveness of temporal verification and all the other related components such as temporal Checkpoint Selection and temporal violation handling. Therefore, an accurate forecasting strategy is required to predict cloud workflow activity durations. However, it is not a trivial issue due to the dynamic nature of cloud computing environments. In this chapter, we present a statistical time-series-based forecasting strategy for scientific cloud workflow activity duration intervals. The comparison results demonstrate that our strategy has better performance than the other existing representative strategies. This chapter is organised as follows. Section 5.1 gives a general introduction about cloud workflow activity durations. Section 5.2 presents the specifically related work and problem analysis. Section 5.3 presents the novel statistical time-series-pattern-based forecasting strategy. Section 5.4 demonstrates the experimental results.
Jinjun Chen - One of the best experts on this subject based on the ideXlab platform.
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Adaptive Selection of Necessary and Sufficient Checkpoints for Dynamic Verification of Temporal Constraints in Grid Workflow Systems
2015Co-Authors: Jinjun Chen, Yun YangAbstract:In grid workflow systems, a Checkpoint Selection strategy is responsible for selecting Checkpoints for conducting temporal verification at the runtime execution stage. Existing representative check-point Selection strategies often select some unnecessary Checkpoints and omit some necessary ones because they cannot adapt to the dynamics and uncertainty of runtime activity completion duration. In this article, based on the dynamics and uncertainty of runtime activity completion duration, we develop a novel Checkpoint Selection strategy that can adaptively select not only necessary, but also sufficient Checkpoints. Specifically, we introduce a new concept of minimum time redundancy as a key reference parameter for Checkpoint Selection. An important feature of minimum time redun-dancy is that it can adapt to the dynamics and uncertainty of runtime activity completion duration. We develop a method on how to achieve minimum time redundancy dynamically along grid work-flow execution and investigate its relationships with temporal consistency. Based on the method and the relationships, we present our strategy and rigorously prove its necessity and sufficiency. The simulation evaluation further demonstrates experimentally such necessity and sufficiency an
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An Activity Completion Duration based Checkpoint Selection Strategy for Dynamic Verification of Fixed-time Constraints
2013Co-Authors: Jinjun Chen, Yun YangAbstract:In grid workflow systems, to verify temporal constraints efficiently at run-time execution stage, some Checkpoints are often selected so that we only need to conduct temporal verification at such Checkpoints rather than at all activity points. However, existing typical Checkpoint Selection strategies often ignore some necessary Checkpoints and select some unnecessary ones. This would eventually impact overall temporal verification effectiveness and efficiency. To improve such status, in this paper, we develop a new Checkpoint Selection strategy. Specifically, we first investigate the relationships between activity completion duration and the consistency of temporal constraints. Then, based on those relationships we present our new Checkpoint Selection strategy. Our new strategy can avoid the omission of necessary Checkpoints and the Selection of excess unnecessary Checkpoints. Consequently, it can achieve better temporal verification effectiveness and efficiency than the existing typical Checkpoint Selection strategies. The final comparison and quantitative evaluation further demonstrate this result. Key words: grid workflows, temporal constraints, Checkpoint Selection, temporal verification effectiveness, temporal verification efficienc
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Temporal Violation Handling
Temporal QOS Management in Scientific Cloud Workflow Systems, 2012Co-Authors: Xiao Liu, Yun Yang, Jinjun ChenAbstract:Temporal violation handling is the key of the last component in our temporal framework for scientific cloud workflow systems. Clearly, whether a detected temporal violation can be recovered or not mainly depends on the performance of temporal violation handling strategies employed in the system. Meanwhile, since the time overheads and monetary cost for temporal violation handling strategies are usually much more expensive than that of its precedent steps such as Checkpoint Selection and temporal verification, cost-effective temporal violation handling strategies are required to be employed or designed to reduce the overall cost of the temporal framework.
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Forecasting Scientific Cloud Workflow Activity Duration Intervals
Temporal QOS Management in Scientific Cloud Workflow Systems, 2012Co-Authors: Xiao Liu, Yun Yang, Jinjun ChenAbstract:As discussed in Chapter 2, workflow activity duration is one of the basic elements in the temporal consistency model, and thus its accuracy is critical for the effectiveness of temporal verification and all the other related components such as temporal Checkpoint Selection and temporal violation handling. Therefore, an accurate forecasting strategy is required to predict cloud workflow activity durations. However, it is not a trivial issue due to the dynamic nature of cloud computing environments. In this chapter, we present a statistical time-series-based forecasting strategy for scientific cloud workflow activity duration intervals. The comparison results demonstrate that our strategy has better performance than the other existing representative strategies. This chapter is organised as follows. Section 5.1 gives a general introduction about cloud workflow activity durations. Section 5.2 presents the specifically related work and problem analysis. Section 5.3 presents the novel statistical time-series-pattern-based forecasting strategy. Section 5.4 demonstrates the experimental results.
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activity completion duration based Checkpoint Selection for dynamic verification of temporal constraints in grid workflow systems
IEEE International Conference on High Performance Computing Data and Analytics, 2008Co-Authors: Jinjun Chen, Yun YangAbstract:In grid workflow systems, to verify temporal constraints efficiently at the run-time execution stage, some Checkpoints are selected such that temporal verification need only be conducted at those Checkpoints rather than at all activity points. However, existing typical Checkpoint Selection strategies may ignore some necessary Checkpoints and select some unnecessary ones. This eventually impacts overall temporal verification effectiveness and efficiency. To improve such status, in this paper, we develop a new Checkpoint Selection strategy. Specifically, we first investigate the relationships between activity completion duration and the consistency of temporal constraints. Then, based on those relationships we present our new Checkpoint Selection strategy. Our new strategy can avoid the omission of necessary Checkpoints and the Selection of excess unnecessary Checkpoints. Consequently, it can achieve better temporal verification effectiveness and efficiency than the existing typical Checkpoint Selection strategies. The final comparison and quantitative evaluation further demonstrate this result.
Xiao Liu - One of the best experts on this subject based on the ideXlab platform.
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Necessary and sufficient Checkpoint Selection for temporal verification of high-confidence cloud workflow systems
Science China Information Sciences, 2015Co-Authors: Futian Wang, Xiao LiuAbstract:On-time completion is an important temporal QoS (Quality of Service) dimension and one of the fundamental requirements for high-confidence workflow systems. In recent years, a workflow temporal verification framework, which generally consists of temporal constraint setting, temporal Checkpoint Selection, temporal verification, and temporal violation handling, has been the major approach for the high temporal QoS assurance of workflow systems. Among them, effective temporal Checkpoint Selection, which aims to timely detect intermediate temporal violations along workflow execution plays a critical role. Therefore, temporal Checkpoint Selection has been a major topic and has attracted significant efforts. In this paper, we will present an overview of work-flow temporal Checkpoint Selection for temporal verification. Specifically, we will first introduce the throughput based and response-time based temporal consistency models for business and scientific cloud workflow systems, respectively. Then the corresponding benchmarking Checkpoint Selection strategies that satisfy the property of “necessity and sufficiency” are presented. We also provide experimental results to demonstrate the effectiveness of our Checkpoint Selection strategies, and finally points out some possible future issues in this research area.
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selecting Checkpoints along the time line a novel temporal Checkpoint Selection strategy for monitoring a batch of parallel business processes
International Conference on Software Engineering, 2013Co-Authors: Xiao Liu, Yun Yang, Dahai Cao, Dong YuanAbstract:Nowadays, most business processes are running in a parallel, distributed and time-constrained manner. How to guarantee their on-time completion is a challenging issue. In the past few years, temporal Checkpoint Selection which selects a subset of workflow activities for verification of temporal consistency has been proved to be very successful in monitoring single, complex and large size scientific workflows. An intuitive approach is to apply those strategies to individual business processes. However, in such a case, the total number of Checkpoints will be enormous, namely the cost for system monitoring and exception handling could be excessive. To address such an issue, we propose a brand new idea which selects time points along the workflow execution time line as Checkpoints to monitor a batch of parallel business processes simultaneously instead of individually. Based on such an idea, a set of new definitions as well as a time-point based Checkpoint Selection strategy are presented in this paper. Our preliminary results demonstrate that it can achieve an order of magnitude reduction in the number of Checkpoints while maintaining satisfactory on-time completion rates compared with the state-of-the-art activity-point based Checkpoint Selection strategy.
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Temporal Violation Handling
Temporal QOS Management in Scientific Cloud Workflow Systems, 2012Co-Authors: Xiao Liu, Yun Yang, Jinjun ChenAbstract:Temporal violation handling is the key of the last component in our temporal framework for scientific cloud workflow systems. Clearly, whether a detected temporal violation can be recovered or not mainly depends on the performance of temporal violation handling strategies employed in the system. Meanwhile, since the time overheads and monetary cost for temporal violation handling strategies are usually much more expensive than that of its precedent steps such as Checkpoint Selection and temporal verification, cost-effective temporal violation handling strategies are required to be employed or designed to reduce the overall cost of the temporal framework.
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Forecasting Scientific Cloud Workflow Activity Duration Intervals
Temporal QOS Management in Scientific Cloud Workflow Systems, 2012Co-Authors: Xiao Liu, Yun Yang, Jinjun ChenAbstract:As discussed in Chapter 2, workflow activity duration is one of the basic elements in the temporal consistency model, and thus its accuracy is critical for the effectiveness of temporal verification and all the other related components such as temporal Checkpoint Selection and temporal violation handling. Therefore, an accurate forecasting strategy is required to predict cloud workflow activity durations. However, it is not a trivial issue due to the dynamic nature of cloud computing environments. In this chapter, we present a statistical time-series-based forecasting strategy for scientific cloud workflow activity duration intervals. The comparison results demonstrate that our strategy has better performance than the other existing representative strategies. This chapter is organised as follows. Section 5.1 gives a general introduction about cloud workflow activity durations. Section 5.2 presents the specifically related work and problem analysis. Section 5.3 presents the novel statistical time-series-pattern-based forecasting strategy. Section 5.4 demonstrates the experimental results.
Haoyu Luo - One of the best experts on this subject based on the ideXlab platform.
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adaptive temporal verification and violation handling for time constrained business cloud workflows
International Conference on Service Oriented Computing, 2018Co-Authors: Haoyu Luo, Jin Liu, Bo HanAbstract:To achieve on-time completion of time-constrained business cloud workflows, a large number of parallel cloud workflow instances need to be constantly monitored so that temporal violations (namely intermediate runtime delays) can be detected and handled timely. Over the last few years, many strategies have been proposed but they are not adaptive enough to capture the dynamic behaviors of business cloud workflows. In this paper, we introduce the idea of “adaptiveness” into our strategy design. Specifically, we first present an adaptive temporal Checkpoint Selection strategy where the time intervals between Checkpoints are adaptively determined at runtime, and then propose a matching temporal violation handling strategy which can determine the required lifecycle of cloud services. The evaluation results demonstrate that our adaptive strategy can achieve both higher efficiency and better cost effectiveness compared with conventional strategies.
Bo Han - One of the best experts on this subject based on the ideXlab platform.
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adaptive temporal verification and violation handling for time constrained business cloud workflows
International Conference on Service Oriented Computing, 2018Co-Authors: Haoyu Luo, Jin Liu, Bo HanAbstract:To achieve on-time completion of time-constrained business cloud workflows, a large number of parallel cloud workflow instances need to be constantly monitored so that temporal violations (namely intermediate runtime delays) can be detected and handled timely. Over the last few years, many strategies have been proposed but they are not adaptive enough to capture the dynamic behaviors of business cloud workflows. In this paper, we introduce the idea of “adaptiveness” into our strategy design. Specifically, we first present an adaptive temporal Checkpoint Selection strategy where the time intervals between Checkpoints are adaptively determined at runtime, and then propose a matching temporal violation handling strategy which can determine the required lifecycle of cloud services. The evaluation results demonstrate that our adaptive strategy can achieve both higher efficiency and better cost effectiveness compared with conventional strategies.
