ADEPTdistribution - Scalability in WfMS and Distributed WF Control

Description

In large-scale application scenarios, performance is a critical issue. The execution of enterprise-wide and cross-organizational workflows may generate a very high load, which does not only affect workflow servers but also the underlying communication network. Due to the high amount of communication between workflow server(s) and  clients, the network may become a bottleneck, especially if a large amount of "long-distance" communication occurs. In order to avoid such bottlenecks we aim to reduce the network load by partitioning workflow schemes and by migrating the control of corresponding workflow instances from one server to another during run-time if favorable; i.e., a workflow instance may no longer be controlled by only one workflow server. When performing such a migration, at least a description of the instance state (including workflow relevant data) and of previously applied instance changes has to be transmitted to the target server. In order to avoid unnecessary, subnet-spanning communication between servers, however, parallel branches of a workflow instance should be controlled independently from each other – at least as no synchronization due to other reasons (e.g., a dynamic workflow change) becomes necessary.

The overall project goal was to develop a comprehensive approach for achieving scalability in (distributed) workflow management systems. In particular, we address the following challenges: 

  • The load caused by the execution of a large number of workflow instances must be adequately distributed to servers such that a single server does not become a bottleneck.

  • The assignment of servers to single activities (i.e., the partitioning of the respective workflow schema) must be done in a way that minimizes the overall communication load.

  • Necessary migrations between workflow servers must be efficiently performed; i.e., they should only require a minimal amount of data to be transmitted.

  • The assignment of workflow servers to single activities must be done in a flexible way. For example, to achieve high locality between the workflow server controlling a particular activity and the potential actors working on it, variable server assignments must be supported.

  • Even for workflow instances with partitioned schema and distributed control the support of dynamic changes is indispensable. We aim at an approach that provides the full change functionality as in the central case while, at the same time, achieving an extremely favorable behavior with respect to communication costs.

The developed concepts were implemented in the ADEPT1 workflow management systems. Tool presentations and demonstrations on distributed workflow management were given at several conferences and industrial fairs, including EDBT’2000, BIS’2000, and CeBIT’2000.

 

 

Fig. 1: WF Schema Partitioning and Distributed Workflow Control

Partners

  • Institute of Databases and Information Systems

Funding

  • This research project was partially funded by the German Research Foundation (Deutsche Forschungsgemeinschaft; DFG)

Duration

  • 1999 - 2001

Additional Information

Publications

| 2009 | 2007 | 2004 | 2003 | 2001 | 2000 | 1999 | 1998 | 1997 |

2009

Reichert, Manfred and Bauer, Thomas and Dadam, Peter (2009) Flexibility for Distributed Workflows. IGI Global, In: Handbook of Research on Complex Dynamic Process Management: Techniques for Adaptability in Turbulent Environments. pp. 137-171. file

2007

Bauer, Thomas and Reichert, Manfred (2007) An Approach for Supporting Ad-hoc Modifications in Distributed Workflow Management Systems. Technical Report TR-CTIT-07-80 , University of Twente. file
Reichert, Manfred and Bauer, Thomas (2007) Supporting Ad-hoc Changes in Distributed Workflow Management Systems. In: 15th Int'l Conf. on Coop. Information Systems (CoopIS'07), Vilamoura, Algarve, Portugal, November 2007, LNCS 4803, Springer, pp. 150-168. file

2004

Bauer, Thomas and Reichert, Manfred (2004) Dynamic Change of Server Assignments in Distributed Workflow Management Systems. In: Proc. 6th Int'l Conf. Enterprise Information Systems (ICEIS'04), Porto, Portugal, pp. 91-98. file

2003

Bauer, Thomas and Reichert, Manfred and Dadam, Peter (2003) Intra-subnet Load Balancing in Distributed Workflow Management Systems. Int'l Journal of Cooperative Information Systems, 12(3): 205-323. file

2001

Bauer, Thomas and Reichert, Manfred and Dadam, Peter (2001) Adaptives und verteiltes Workflow-Management. In: Proc. Datenbanksysteme in Büro, Technik und Wissenschaft (BTW' 01), Oldenburg, Germany, Springer, pp. 47-66. file
Bauer, Thomas and Reichert, Manfred and Dadam, Peter (2001) Effiziente Übertragung von Prozessinstanzdaten in verteilten Workflow-Management-Systemen. Informatik - Forschung und Entwicklung, 16(2): 76-92, Springer. file
Bauer, Thomas and Reichert, Manfred and Dadam, Peter (2001) Dynamische Ablaufänderungen in verteilten Workflow-Management-Systemen. Datenbank Spektrum, dpunkt verlag, Vol. 1, pp. 68-77. file
Bauer, Thomas (2001) Effiziente Realisierung unternehmensweiter Workflow-Management-Systeme. Phd thesis, Uni Ulm. file

2000

Bauer, Thomas and Dadam, Peter (2000) Efficient Distributed Workflow Management Based on Variable Server Assignments. In: Proc. 12th Int'l Conf. on Advanced Information Systems Engineering (CAiSE '00), Stockholm, Sweden, LNCS 1789, Springer, pp. 94-109. file
Bauer, Thomas and Reichert, Manfred and Dadam, Peter (2000) Adaptives und verteiltes Workflow-Management. Technical Report UIB-2000-10, Universität Ulm. file
Bauer, Thomas and Dadam, Peter (2000) Vermeidung von Überlastsituationen durch Replikation von Workflow-Servern in ADEPT. Technical Report UIB-2000-09, Universität Ulm. file
Bauer, Thomas and Reichert, Manfred and Dadam, Peter (2000) Effiziente Durchführung von Prozessmigrationen in verteilten Workflow-Management-Systemen. Technical Report UIB-2000-08, Universität Ulm. file
Bauer, Thomas and Dadam, Peter (2000) Variable Serverzuordnungen und komplexe Bearbeiterzuordnungen im Workflow-Management-System ADEPT. Technical Report UIB-2000-02, Universität Ulm. file

1999

Bauer, Thomas and Dadam, Peter (1999) Verteilungsmodelle für Workflow-Management-Systeme - Klassifikation und Simulation. Informatik - Forschung und Entwicklung, 14(4): 203-217, Springer. file
Bauer, Thomas and Dadam, Peter (1999) Efficient Distributed Control of Enterprise-Wide and Cross-EnterpriseWorkflows. In: Proc. Workshop Informatik '99, Paderborn, Germany, CEUR Workshop Proceedings 24, Dadam, P.; Reichert, M. , pp. 25-32. file
Bauer, Thomas and Dadam, Peter (1999) Efficient Distributed Workflow Management Based on Variable Server Assignments. Technical Report UIB-1999-09, Universität Ulm. file
Bauer, Thomas and Dadam, Peter (1999) Verteilungsmodelle für Workflow-Management-Systeme - Klassifikation und Simulation. Technical Report UIB-1999-02, Universität Ulm. file
Reichert, Manfred and Bauer, Thomas and Dadam, Peter (1999) Enterprise-Wide and Cross-Enterprise Workflow Management: Challenges and Research Issues for Adaptive Workflows. In: Proc. Workshop Informatik '99, Paderborn, Germany, CEUR Workshop Proceedings, 24, Dadam, P.; Reichert, M., pp. 56-64. file

1998

Bauer, Thomas and Dadam, Peter (1998) Variable Migration von Workflows in ADEPT. Technical Report UIB-1998-09, Universität Ulm. file
Bauer, Thomas and Dadam, Peter (1998) Architekturen für skalierbare Workflow-Management-Systeme - Klassifikation und Analyse. Technical Report UIB-1998-02, Universität Ulm. file

1997

Bauer, Thomas and Dadam, Peter (1997) A Distributed Execution Environment for Large-Scale Workflow Management Systems with Subnets and Server Migration. In: Proc. Int'l Conf. on Cooperative Information Systems (CoopIS '97), Kiawah Island, South Carolina, IEEE Computer Society Press, pp. 99-108. file
Bauer, Thomas and Dadam, Peter (1997) A Distributed Execution Environment for Large-Scale Workflow Management Systems with Subnets and Server Migration. Technical Report UIB-1997-03, Universität Ulm. file

Master & Bachelor Theses

| 1999 | 1998 | 1997 |

1999

Zeitler, Jochen (1999) Integration von Verteilungskomponenten in ein adaptives Workflow-Management-System. Diploma thesis, Universität Ulm. file

1998

Enderlin, Holger (1998) Realisierung einer verteilten Workflow-Ausführungskomponente auf Basis von IBM FlowMark. Diploma thesis, Universität Ulm. file

1997

Klöpfer, Anita (1997) Vergleich verschiedener TP-Monitore unter konzeptionellen und anwendungsorientierten Aspekten. Diploma thesis, Universität Ulm. file