DocumentCode :
2545417
Title :
Workflow Refactoring for Concurrent Task Execution
Author :
Mingzhong Wang ; Jinjun Chen ; Liehuang Zhu
Author_Institution :
Beijing Lab. of Intell. Inf. Technol., Beijing Inst. of Technol., Beijing, China
fYear :
2012
fDate :
1-3 Nov. 2012
Firstpage :
629
Lastpage :
636
Abstract :
The performance and reliability of workflow execution are highly dependent on the scheduling algorithm. However, existing approaches usually confines the scheduling on the predefined workflow structure, neglecting the possibility that a workflow graph itself may be changeable when certain conditions are satisfied. Therefore, in this paper we propose the concept of graph refactoring which transforms certain types of sequential tasks to run in parallel without changing system´s functionality. We first propose a classification of task dependencies in DAG-style workflow graphs as data, strict control, and loose control dependency according to task interaction and user requirements, and identify that previously sequential task ordering in loose control dependency can be scheduled to run in parallel as long as supporting services are trustworthy. Corresponding refactoring algorithms are designed to traverse, restructure, and parallelize loose control dependencies in the graph when the reputations of related executing services are above certain threshold. Experiments and analysis show that graph refactoring can improve the system performance scalably because of concurrent execution of previously sequential tasks.
Keywords :
concurrency control; directed graphs; scheduling; workflow management software; DAG-style workflow graph; concurrent task execution; data dependency; directed acyclic graph; graph refactoring concept; loose control dependency; scheduling algorithm; sequential task; sequential task ordering; strict control dependency; task classification; task interaction; user requirement; workflow execution; workflow graph; workflow refactoring; Processor scheduling; Reliability; Schedules; Scheduling; System performance; Transforms; Concurrency; Refactoring; Scheduling; Workflow;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Cloud and Green Computing (CGC), 2012 Second International Conference on
Conference_Location :
Xiangtan
Print_ISBN :
978-1-4673-3027-5
Type :
conf
DOI :
10.1109/CGC.2012.82
Filename :
6382881
Link To Document :
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