@inproceedings {INPROC-2017-52,
author = {David Richard Sch{\"a}fer and Kurt Rothermel and Muhammad Adnan Tariq},
title = {{Exploring the Search Space between Active and Passive Workflow Replication}},
booktitle = {Proceedings of the 10th IEEE International Conference on Service-Oriented Computing and Applications (SOCA), Kanazawa, Japan, November 22-25, 2017},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--8},
type = {Konferenz-Beitrag},
month = {November},
year = {2017},
keywords = {SOA; availability; workflows; replication},
language = {Deutsch},
cr-category = {C.2.4 Distributed Systems,
C.4 Performance of Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2017-52/INPROC-2017-52.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-52&engl=0}
}
@inproceedings {INPROC-2016-15,
author = {David Richard Sch{\"a}fer and Andreas Wei{\ss} and Muhammad Adnan Tariq and Vasilios Andrikopoulos and Santiago G{\'o}mez S{\'a}ez and Lukas Krawczyk and Kurt Rothermel},
title = {{HAWKS: A System for Highly Available Executions of Workflows}},
booktitle = {Proceedings of the 13th IEEE International Conference on Services Computing: SCC'16; San Francisco, California, USA, June 27-July 2, 2016},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {130--137},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2016},
doi = {10.1109/SCC.2016.24},
keywords = {SOA; workflows; availability; replication; performance},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
C.4 Performance of Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2016-15/INPROC-2016-15.pdf,
http://dx.doi.org/10.1109/SCC.2016.24},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The workflow technology is the de facto standard for managing business
processes. Today, workflows are even used for automating interactions and
collaborations between business partners, e.g., for enabling just-in-time
production. Every workflow that is part of such a collaboration needs to be
highly available. Otherwise, the business operations, e.g., the production,
might be hindered or even stopped. Since today's business partners are
scattered across the globe, the workflows are executed in a highly distributed
and heterogeneous environment. Those environments are, however, failure-prone
and, thus, providing availability is not trivial. In this work, we improve
availability by replicating workflow executions, while ensuring that the
outcome is the same as in a non-replicated execution. For making workflow
replication easily usable with current workflow technology, we derive the
requirements for modeling a workflow replication system. Then, we propose the
HAWKS system, which adheres to the previously specified requirements and is
compatible with current technology. We implement a proof-of-concept in the
open-source workflow execution engine Apache ODE for demonstrating this
compatibility. Finally, we extensively evaluate the impact of using HAWKS in
terms of performance and availability in the presence of failures.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-15&engl=0}
}
@inproceedings {INPROC-2014-57,
author = {David Richard Sch{\"a}fer and Santiago G{\'o}mez S{\'a}ez and Thomas Bach and Vasilios Andrikopoulos and Muhammad Adnan Tariq},
title = {{Towards Ensuring High Availability in Collective Adaptive Systems}},
booktitle = {Proceedings of the First International Workshop of Business Processes in Collective Adaptive Systems: BPCAS'14; Eindhoven, Netherlands, September 8, 2014},
publisher = {Springer},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Workshop-Beitrag},
month = {September},
year = {2014},
keywords = {workflows; high availability; service discovery; process fragment injection},
language = {Englisch},
cr-category = {D.2.0 Software Engineering General,
D.2.11 Software Engineering Software Architectures,
D.2.12 Software Engineering Interoperability,
C.2.4 Distributed Systems,
C.4 Performance of Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-57/INPROC-2014-57.pdf},
contact = {david.schaefer@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Collective Adaptive Systems support the interaction and adaptation of virtual
and physical entities towards achieving common objectives. For these systems,
several challenges at the modeling, provisioning, and execution phases arise.
In this position paper, we define the necessary underpinning concepts and
identify requirements towards ensuring high availability in such systems. More
specifically, based on a scenario from the EU Project ALLOW Ensembles, we
identify the necessary requirements and derive an architectural approach that
aims at ensuring high availability by combining active workflow replication,
service selection, and dynamic compensation techniques.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-57&engl=0}
}
@inproceedings {INPROC-2014-29,
author = {David Richard Sch{\"a}fer and Thomas Bach and Muhammad Adnan Tariq and Kurt Rothermel},
title = {{Increasing Availability of Workflows Executing in a Pervasive Environment}},
booktitle = {Proceedings of the 2014 IEEE International Conference on Services Computing},
address = {Anchorage, AK, USA},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {717--724},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2014},
doi = {10.1109/SCC.2014.98},
isbn = {978-1-4799-5066-9/14},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
C.4 Performance of Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-29/INPROC-2014-29.pdf,
http://dx.doi.org/10.1109/SCC.2014.98},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Workflows have gained enormous importance to organize and manage business
processes. With the recent advent of smartphones and mobile applications,
traditional business process management is shifting. Now, long-running business
processes (workflows) have to be executed in large-scale distributed and
pervasive environments. Due to the heterogeneity and high dynamicity of such
environments, they are vulnerable to frequent communication and device failures
and, thus, impose new requirements on the execution of workflows. To increase
the availability, we concurrently executed restructured replicas of workflows
on multiple nodes. We developed techniques to generate differently structured
replicas and propose a metric that identifies the set of replicas that ensures
the highest availability during execution. Finally, we presented a distributed
algorithm to coordinate and synchronize the concurrent execution of the
identified replicas while maintaining the original workflow semantics. Our
methods approximately double the availability during execution, while our
generation techniques produce almost optimal replicas over a hundred times
faster.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-29&engl=0}
}