The Experts below are selected from a list of 32010 Experts worldwide ranked by ideXlab platform
Thomas Fahringer - One of the best experts on this subject based on the ideXlab platform.
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Run-time Optimization for Grid Workflow Applications
Society Press, 2014Co-Authors: Rubing Duan, Radu Prodan, Thomas FahringerAbstract:The execution of Workflow Applications on the Grid is a com-plex issue because of its dynamic and heterogeneous nature. While the Grid provides good potential for achieving high per-formance, it also introduces a broad set of unpredictable over-heads and possible failures. In this paper we present new meth-ods for scalable and fault tolerant coordination of Workflows in dynamic Grid environments, including partitioning, static and dynamic optimization, as well as Virtual Single Execution En-vironment, incorporated into the ASKALON distributed work-flow Enactment Engine. We demonstrate the effectiveness of our methods on a material science Workflow Application executed in a real-world Grid environment.
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Fine-Grain Interoperability of Scientific Workflows in Distributed Computing Infrastructures
Journal of Grid Computing, 2013Co-Authors: Kassian Plankensteiner, Radu Prodan, Thomas Fahringer, Johan Montagnat, Matthias Janetschek, David Rogers, Ian Harvey, Ian Taylor, Ákos Balaskó, Péter KacsukAbstract:Today there exist a wide variety of scientific Workflow management systems, each designed to fulfill the needs of a certain scientific community. Unfortunately, once a Workflow Application has been designed in one particular system it becomes very hard to share it with users working with different systems. Portability of Workflows and interoperability between current systems barely exists. In this work, we present the fine-grained interoperability solution proposed in the SHIWA European project that brings together four representative European Workflow systems: ASKALON, MOTEUR, WS-PGRADE, and Triana. The proposed interoperability is realised at two levels of abstraction: abstract and concrete. At the abstract level, we propose a generic Interoperable Workflow Intermediate Representation (IWIR) that can be used as a common bridge for translating Workflows between different languages independent of the underlying distributed computing infrastructure. At the concrete level, we propose a bundling technique that aggregates the abstract IWIR representation and concrete task representations to enable Workflow instantiation, execution and scheduling. We illustrate case studies using two real-Workflow Applications designed in a native environment and then translated and executed by a foreign Workflow system in a foreign distributed computing infrastructure.
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GRID - Run-time Optimisation of Grid Workflow Applications
2006 7th IEEE ACM International Conference on Grid Computing, 2006Co-Authors: Rubing Duan, Radu Prodan, Thomas FahringerAbstract:The execution of Workflow Applications on the Grid is a complex issue because of its dynamic and heterogeneous nature. While the Grid provides good potential for achieving high performance, it also introduces a broad set of unpredictable overheads and possible failures. In this paper we present new methods for scalable and fault tolerant coordination of Workflows in dynamic Grid environments, including partitioning, static and dynamic optimisation, as well as Virtual Single Execution Environment, incorporated into the ASKALON distributed Workflow Enactment Engine. We demonstrate the effectiveness of our methods on a material science Workflow Application executed in a real-world Grid environment.
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dee a distributed fault tolerant Workflow enactment engine for grid computing
High Performance Computing and Communications, 2005Co-Authors: Rubing Duan, Radu Prodan, Thomas FahringerAbstract:It is a complex task to design and implement a Workflow management system that supports scalable executions of large-scale scientific Workflows for dynamic and heterogeneous Grid environments. In this paper we describe the Distributed Workflow Enactment Engine (DEE) of the ASKALON Grid Application development environment for Grid computing. DEE proposes a de-centralized architecture that simplifies and reduces the overhead for managing large Workflows through partitioning, improved data locality, and reduced Workflow-level checkpointing overhead. We report experimental results for a real-world material science Workflow Application.
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HPCC - DEE: a distributed fault tolerant Workflow enactment engine for grid computing
High Performance Computing and Communications, 2005Co-Authors: Rubing Duan, Radu Prodan, Thomas FahringerAbstract:It is a complex task to design and implement a Workflow management system that supports scalable executions of large-scale scientific Workflows for dynamic and heterogeneous Grid environments. In this paper we describe the Distributed Workflow Enactment Engine (DEE) of the ASKALON Grid Application development environment for Grid computing. DEE proposes a de-centralized architecture that simplifies and reduces the overhead for managing large Workflows through partitioning, improved data locality, and reduced Workflow-level checkpointing overhead. We report experimental results for a real-world material science Workflow Application.
Rajkumar Buyya - One of the best experts on this subject based on the ideXlab platform.
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Optimizing the makespan and reliability for Workflow Applications with reputation and a look-ahead genetic algorithm
Future Generation Computer Systems, 2011Co-Authors: Xiaofeng Wang, Chee Shin Yeo, Rajkumar BuyyaAbstract:For Applications in large-scale distributed systems, it is becoming increasingly important to provide reliable scheduling by evaluating the reliability of resources. However, most existing reputation models used for reliability evaluation ignore the critical influence of task runtime. In addition, most previous work uses list heuristics to optimize the makespan and reliability of Workflow Applications instead of genetic algorithms (GAs), which can give several satisfying solutions for choice. Hence, in this paper, we first propose the reliability-driven (RD) reputation, which is time dependent, and can be used to effectively evaluate the reliability of a resource in widely distributed systems. We then propose a look-ahead genetic algorithm (LAGA) which utilizes the RD reputation to optimize both the makespan and the reliability of a Workflow Application. The LAGA uses a novel evolution and evaluation mechanism: (i) the evolution operators evolve the task-resource mapping of a scheduling solution and (ii) the evaluation step determines the task order of solutions by using our proposed max-min strategy, which is the first two-phase strategy that can work with GAs. Our experiments show that the RD reputation improves the reliability of an Application with more accurate reputations, while the LAGA provides better solutions than existing list heuristics and evolves to better solutions more quickly than a traditional GA.
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A Particle Swarm Optimization-Based Heuristic for Scheduling Workflow Applications in Cloud Computing Environments
2010 24th IEEE International Conference on Advanced Information Networking and Applications, 2010Co-Authors: Suraj Pandey, Sanjeela Guru, Linlin Wu, Rajkumar BuyyaAbstract:Cloud computing environments facilitate Applications by providing virtualized resources that can be provisioned dynamically. However, users are charged on a pay-per-use basis. User Applications may incur large data retrieval and execution costs when they are scheduled taking into account only the `execution time'. In addition to optimizing execution time, the cost arising from data transfers between resources as well as execution costs must also be taken into account. In this paper, we present a particle swarm optimization (PSO) based heuristic to schedule Applications to cloud resources that takes into account both computation cost and data transmission cost. We experiment with a Workflow Application by varying its computation and communication costs. We compare the cost savings when using PSO and existing `Best Resource Selection' (BRS) algorithm. Our results show that PSO can achieve: (a) as much as 3 times cost savings as compared to BRS, and (b) good distribution of workload onto resources.
Leila Jemni Ben Ayed - One of the best experts on this subject based on the ideXlab platform.
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COMPSAC Workshops - Refinement Based Modeling of Workflow Applications Using UML Activity Diagrams
2013 IEEE 37th Annual Computer Software and Applications Conference Workshops, 2013Co-Authors: Ahlem Ben Younes, Leila Jemni Ben Ayed, Yousra Bendaly Hlaoui, Rahma JlassiAbstract:Specifying a complex system, such as Workflow Applications, is a difficult task, which can not be done in one step. The stepwise refinement technique. facilitates the understanding of complex systems by dealing with the major issues before getting involved in the details. This papers presents a refinement based modelling approach of Workflow Applications using UML Activity Diagrams. The proposed approach allows an incrementally developing more and more detailed models, preserving correctness in each step. We provide formal support for building process refinement graphs that are completely proved correct. We illustrate, as well, the proposed technique through an example of Workflow Application specified by our developed tool supporting the approach. This tool assists the developer in the task of refinement steps.
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COMPSAC Workshops - UML AD Refinement Patterns for Modeling Workflow Applications
2012 IEEE 36th Annual Computer Software and Applications Conference Workshops, 2012Co-Authors: Ahlem Ben Younes, Leila Jemni Ben Ayed, Yousra Bendaly HlaouiAbstract:In this paper, we propose an UML Activity Diagram (AD) approach based on stepwise refinement technique for modeling and describing Workflow Applications. Thus, we present a set of UML AD refinement patterns that support the different forms of refining process in a Workflow. The Workflow Application is constructed in a hierarchical fashion. We show that thanks to the hierarchical Workflow construction by refinement, a simple view of the Workflow is maintained at each level of abstraction. In addition, we provide formal support for building process refinement graphs that are complete, proved correct.
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uml_ad2eventb an approach to generating event b specification from uml activity diagrams for the Workflows specification and verification
IEEE Congress on Services, 2009Co-Authors: Ahlem Ben Younes, Leila Jemni Ben AyedAbstract:In this paper, we present a new approach to generating Event B specification from UML Activity Diagrams (AD). The goal of this work is to define a formal semantics of activity diagrams that is suitable for Workflows modelling. The semantics should allow verification of functional requirements using the B powerful support tools like B4free. In important characteristic of Workflows is that the Workflow systems are reactive systems. In this paper, we present a formal syntax and semantic for UML AD endowed with interactive aspects (send/receive event concepts), and we illustrate the proposed technique by an example of Workflow Application.
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COMPSAC - From UML Activity Diagrams to Event B for the Specification and the Verification of Workflow Applications
2008 32nd Annual IEEE International Computer Software and Applications Conference, 2008Co-Authors: A. Ben Younes, Leila Jemni Ben AyedAbstract:This paper presents a new event-B based approach to reasoning about Workflow Applications. We show how an event-B model can be structured from UML Activity diagrams (UML AD) and then used to give a formal semantic to UML AD which supports proofs of their correctness. More precisely, we give rules for the translation of UML AD into event-B language. In particular, we propose a solution that uses the refinement in Event B to encode the hierarchical decomposition of activities in UML AD. The event-B method allows the definition of invariant describing required properties (deadlock-inexistence, liveness, fairness) and provides an automatic proof. We discuss the contributions and by an example of a Workflow Application, we illustrate the proposed approach.
Radu Prodan - One of the best experts on this subject based on the ideXlab platform.
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Run-time Optimization for Grid Workflow Applications
Society Press, 2014Co-Authors: Rubing Duan, Radu Prodan, Thomas FahringerAbstract:The execution of Workflow Applications on the Grid is a com-plex issue because of its dynamic and heterogeneous nature. While the Grid provides good potential for achieving high per-formance, it also introduces a broad set of unpredictable over-heads and possible failures. In this paper we present new meth-ods for scalable and fault tolerant coordination of Workflows in dynamic Grid environments, including partitioning, static and dynamic optimization, as well as Virtual Single Execution En-vironment, incorporated into the ASKALON distributed work-flow Enactment Engine. We demonstrate the effectiveness of our methods on a material science Workflow Application executed in a real-world Grid environment.
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Fine-Grain Interoperability of Scientific Workflows in Distributed Computing Infrastructures
Journal of Grid Computing, 2013Co-Authors: Kassian Plankensteiner, Radu Prodan, Thomas Fahringer, Johan Montagnat, Matthias Janetschek, David Rogers, Ian Harvey, Ian Taylor, Ákos Balaskó, Péter KacsukAbstract:Today there exist a wide variety of scientific Workflow management systems, each designed to fulfill the needs of a certain scientific community. Unfortunately, once a Workflow Application has been designed in one particular system it becomes very hard to share it with users working with different systems. Portability of Workflows and interoperability between current systems barely exists. In this work, we present the fine-grained interoperability solution proposed in the SHIWA European project that brings together four representative European Workflow systems: ASKALON, MOTEUR, WS-PGRADE, and Triana. The proposed interoperability is realised at two levels of abstraction: abstract and concrete. At the abstract level, we propose a generic Interoperable Workflow Intermediate Representation (IWIR) that can be used as a common bridge for translating Workflows between different languages independent of the underlying distributed computing infrastructure. At the concrete level, we propose a bundling technique that aggregates the abstract IWIR representation and concrete task representations to enable Workflow instantiation, execution and scheduling. We illustrate case studies using two real-Workflow Applications designed in a native environment and then translated and executed by a foreign Workflow system in a foreign distributed computing infrastructure.
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IWIR: A Language Enabling Portability Across Grid Workflow Systems
2011Co-Authors: Kassian Plankensteiner, Johan Montagnat, Radu ProdanAbstract:Today there are many different scientific Grid Workflow man- agement systems using a wide array of custom Workflow languages. Some of them are geared towards a data-based view, some are geared towards a control-flow based view and others try to be as generic, and therefore often com- plex, as possible. All of these languages and custom work- flow management system front-ends fulfill special needs and Workflow creation paradigms for their respective user com- munities. The problem is that once a Workflow Application has been created in one of these systems, it becomes very hard to share the Workflow with users working with differ- ent systems. Portability and interoperability between cur- rent systems barely exists. In this work, we present a com- mon Workflow language for use as an intermediate exchange representation by multiple Workflow systems. It comprises atomic tasks, compound tasks including conditionals, se- quential and parallel loops as well as an expressive set of data types and data flow constructs.
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GRID - Run-time Optimisation of Grid Workflow Applications
2006 7th IEEE ACM International Conference on Grid Computing, 2006Co-Authors: Rubing Duan, Radu Prodan, Thomas FahringerAbstract:The execution of Workflow Applications on the Grid is a complex issue because of its dynamic and heterogeneous nature. While the Grid provides good potential for achieving high performance, it also introduces a broad set of unpredictable overheads and possible failures. In this paper we present new methods for scalable and fault tolerant coordination of Workflows in dynamic Grid environments, including partitioning, static and dynamic optimisation, as well as Virtual Single Execution Environment, incorporated into the ASKALON distributed Workflow Enactment Engine. We demonstrate the effectiveness of our methods on a material science Workflow Application executed in a real-world Grid environment.
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dee a distributed fault tolerant Workflow enactment engine for grid computing
High Performance Computing and Communications, 2005Co-Authors: Rubing Duan, Radu Prodan, Thomas FahringerAbstract:It is a complex task to design and implement a Workflow management system that supports scalable executions of large-scale scientific Workflows for dynamic and heterogeneous Grid environments. In this paper we describe the Distributed Workflow Enactment Engine (DEE) of the ASKALON Grid Application development environment for Grid computing. DEE proposes a de-centralized architecture that simplifies and reduces the overhead for managing large Workflows through partitioning, improved data locality, and reduced Workflow-level checkpointing overhead. We report experimental results for a real-world material science Workflow Application.
Rubing Duan - One of the best experts on this subject based on the ideXlab platform.
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Run-time Optimization for Grid Workflow Applications
Society Press, 2014Co-Authors: Rubing Duan, Radu Prodan, Thomas FahringerAbstract:The execution of Workflow Applications on the Grid is a com-plex issue because of its dynamic and heterogeneous nature. While the Grid provides good potential for achieving high per-formance, it also introduces a broad set of unpredictable over-heads and possible failures. In this paper we present new meth-ods for scalable and fault tolerant coordination of Workflows in dynamic Grid environments, including partitioning, static and dynamic optimization, as well as Virtual Single Execution En-vironment, incorporated into the ASKALON distributed work-flow Enactment Engine. We demonstrate the effectiveness of our methods on a material science Workflow Application executed in a real-world Grid environment.
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GRID - Run-time Optimisation of Grid Workflow Applications
2006 7th IEEE ACM International Conference on Grid Computing, 2006Co-Authors: Rubing Duan, Radu Prodan, Thomas FahringerAbstract:The execution of Workflow Applications on the Grid is a complex issue because of its dynamic and heterogeneous nature. While the Grid provides good potential for achieving high performance, it also introduces a broad set of unpredictable overheads and possible failures. In this paper we present new methods for scalable and fault tolerant coordination of Workflows in dynamic Grid environments, including partitioning, static and dynamic optimisation, as well as Virtual Single Execution Environment, incorporated into the ASKALON distributed Workflow Enactment Engine. We demonstrate the effectiveness of our methods on a material science Workflow Application executed in a real-world Grid environment.
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dee a distributed fault tolerant Workflow enactment engine for grid computing
High Performance Computing and Communications, 2005Co-Authors: Rubing Duan, Radu Prodan, Thomas FahringerAbstract:It is a complex task to design and implement a Workflow management system that supports scalable executions of large-scale scientific Workflows for dynamic and heterogeneous Grid environments. In this paper we describe the Distributed Workflow Enactment Engine (DEE) of the ASKALON Grid Application development environment for Grid computing. DEE proposes a de-centralized architecture that simplifies and reduces the overhead for managing large Workflows through partitioning, improved data locality, and reduced Workflow-level checkpointing overhead. We report experimental results for a real-world material science Workflow Application.
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HPCC - DEE: a distributed fault tolerant Workflow enactment engine for grid computing
High Performance Computing and Communications, 2005Co-Authors: Rubing Duan, Radu Prodan, Thomas FahringerAbstract:It is a complex task to design and implement a Workflow management system that supports scalable executions of large-scale scientific Workflows for dynamic and heterogeneous Grid environments. In this paper we describe the Distributed Workflow Enactment Engine (DEE) of the ASKALON Grid Application development environment for Grid computing. DEE proposes a de-centralized architecture that simplifies and reduces the overhead for managing large Workflows through partitioning, improved data locality, and reduced Workflow-level checkpointing overhead. We report experimental results for a real-world material science Workflow Application.
