TUPLESPACE-BASED INFRASTRUCTURE FOR DECENTRALIZED ENACTMENT OF BPEL PROCESSES

Business processes in WS-BPEL are a manifestation of the two-level-programming paradigm where remote-accessible Web services are composed to potentially complex orchestrations. WSBPEL processes are executed by Workflow Management Systems that navigate through the process\u27 activities and interact with the orchestrated services. While Web service technology enables interactions with remote services, process navigation is typically done in a centralized manner. Especially in scenarios of complex interactions between multiple distributed process participants, this way of process enactment has several drawbacks. In this paper, we outline those drawbacks and propose an alternative approach to execution of BPEL processes in a distributed, decentralized manner

Elastic Business Process Management: State of the Art and Open Challenges for BPM in the Cloud

With the advent of cloud computing, organizations are nowadays able to react rapidly to changing demands for computational resources. Not only individual applications can be hosted on virtual cloud infrastructures, but also complete business processes. This allows the realization of so-called elastic processes, i.e., processes which are carried out using elastic cloud resources. Despite the manifold benefits of elastic processes, there is still a lack of solutions supporting them. In this paper, we identify the state of the art of elastic Business Process Management with a focus on infrastructural challenges. We conceptualize an architecture for an elastic Business Process Management System and discuss existing work on scheduling, resource allocation, monitoring, decentralized coordination, and state management for elastic processes. Furthermore, we present two representative elastic Business Process Management Systems which are intended to counter these challenges. Based on our findings, we identify open issues and outline possible research directions for the realization of elastic processes and elastic Business Process Management.Comment: Please cite as: S. Schulte, C. Janiesch, S. Venugopal, I. Weber, and P. Hoenisch (2015). Elastic Business Process Management: State of the Art and Open Challenges for BPM in the Cloud. Future Generation Computer Systems, Volume NN, Number N, NN-NN., http://dx.doi.org/10.1016/j.future.2014.09.00

Grid-enabled Workflows for Industrial Product Design

This paper presents a generic approach for developing and using Grid-based workflow technology for enabling cross-organizational engineering applications. Using industrial product design examples from the automotive and aerospace industries we highlight the main requirements and challenges addressed by our approach and describe how it can be used for enabling interoperability between heterogeneous workflow engines

Adaptable decentralized orchestration engine for block structured non-transactional workflow in service oriented architecture.

In the Service Oriented Architecture (SOA), business processes are executed by nonscalable centralized orchestration engines. Nonetheless proliferation of business process applications in organizations raises scalability requirements. Decentralized orchestration engines are applied to address the scalability by decentralizing a process into design-time static fragments without considering runtime requirements. The fragments are then encapsulated into runtime components such as agents. The SOA orchestration layer suffers from the lack of adaptability with runtime environment in decentralization of business processes. Accordingly, three aspects of runtime adaptability in decentralization are studied in this thesis. The first aspect is frequent-path adaptability, which is equal to detecting closely-interrelated activities and encapsulating them in the same fragment. Another aspect is proportionalfragment adaptability, which is analogous to the proportionality of produced fragments with number of machines. The last aspect is available-bandwidth adaptability, which is process fragmentation based on current circumstances of communication media. An ever-changing runtime environment along with the mentioned adaptability aspects raises the following research problems: 1) there is no framework to support architectures, decentralization methods, and a feedback loop from runtime environment; 2) current decentralization methods do not consider the frequent-path and proportional-fragment adaptability aspects in creating fragments; 3) there is no algorithm to map runtime circumstances to a suitable decentralization method in order to satisfy the available-bandwidth adaptability. Accordingly, the following research objectives are considered: first, to propose a framework including architectures, decentralization methods, and a feedback loop from runtime environment; second, to improve response-time and throughput of decentralized business processes applying the frequent-path and proportional-fragment adaptability aspects; third, to improve bandwidth-usage of decentralized business processes applying the available-bandwidth adaptability. The contributions of this research are also as follows: i) An Adaptable and Decentralized Workflow Execution Framework (ADWEF) is introduced that proposes an abstraction of a runtime adaptable decentralization in the SOA orchestration layer; ii) two architectures Type-1 and Type-2 are presented for the ADWEF that are able to support the execution of dynamically created fragments; iii) three aspects of runtime adaptability in decentralization namely frequent-path, proportional-fragment and available-bandwidth are introduced; iv) two decentralization methods called Hierarchical Process Decentralization (HPD) and Hierarchical and Intelligent Process Decentralization (HIPD) are presented, which are capable of providing various fragments. The latter considers the frequent-path adaptability and both of them together satisfy both frequent-path and proportionalfragment adaptability aspects; v) A Fuzzy Decentralization Decision Making algorithm (FDDM) is presented based on the fuzzy logic to choose a suitable method of decentralization that satisfies the three adaptability aspects frequent-path,proportional- fragment and available-bandwidth; and, vi) an algorithm is introduced for wiring of dynamic fragments. Evaluations of the three adaptability aspects in the ADWEF demonstrate that the frequent-path adaptability greatly improves response-time, throughput, and bandwidth-usage of decentralized business processes. The proportional-fragment adaptability proves that number of fragments must be proportional to the number of workflow engines machines. The available-bandwidth adaptability which is realized by the FDDM algorithm unifies the mentioned adaptability aspects and reduces the number of exchanged messages compared to other methods

Domain Objects and Microservices for Systems Development: a roadmap

This paper discusses a roadmap to investigate Domain Objects being an adequate formalism to capture the peculiarity of microservice architecture, and to support Software development since the early stages. It provides a survey of both Microservices and Domain Objects, and it discusses plans and reflections on how to investigate whether a modeling approach suited to adaptable service-based components can also be applied with success to the microservice scenario

Decentralized Orchestration of Open Services- Achieving High Scalability and Reliability with Continuation-Passing Messaging

The papers of this thesis are not available in Munin. Paper I: Yu, W.,Haque, A. A. M. “Decentralised web- services orchestration with continuation-passing messaging”. Available in International Journal of Web and Grid Services 2011, 7(3):304–330. Paper II: Haque, A. A. M., Yu, W.: “Peer-to-peer orchestration of web mashups”. Available in International Journal of Adaptive, Resilient and Autonomic Systems 2014, 5(3):40-60. Paper V: Haque, A. A. M., Yu, W.: “Decentralized and reliable orchestration of open services”. In:Service Computation 2014. International Academy, Research and Industry Association (IARIA) 2014 ISBN 978-1-61208-337-7.An ever-increasing number of web applications are providing open services to a wide range of applications. Whilst traditional centralized approaches to services orchestration are successful for enterprise service-oriented systems, they are subject to serious limitations for orchestrating the wider range of open services. Dealing with these limitations calls for decentralized approaches. However, decentralized approaches are themselves faced with a number of challenges, including the possibility of loss of dynamic run-time states that are spread over the distributed environment. This thesis presents a fully decentralized approach to orchestration of open services. Our flow-aware dynamic replication scheme supports both exceptional handling, failure of orchestration agents and recovers from fail situations. During execution, open services are conducted by a network of orchestration agents which collectively orchestrate open services using continuation-passing messaging. Our performance study showed that decentralized orchestration improves the scalability and enhances the reliability of open services. Our orchestration approach has a clear performance advantage over traditional centralized orchestration as well as over the current practice of web mashups where application servers themselves conduct the execution of the composition of open web services. Finally, in our empirical study we presented the overhead of the replication approach for services orchestration