@inproceedings {INPROC-2019-36,
author = {Vladimir Yussupov and Uwe Breitenb{\"u}cher and Michael Hahn and Frank Leymann},
title = {{Serverless Parachutes: Preparing Chosen Functionalities for Exceptional Workloads}},
booktitle = {Proceedings of the 2019 IEEE 23rd International Enterprise Distributed Object Computing Conference (EDOC 2019)},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {226--235},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2019},
doi = {10.1109/EDOC.2019.00035},
keywords = {Serverless; FaaS; Function-as-a-Service; Scalability; Failover; Annotation},
language = {Englisch},
cr-category = {D.2.2 Software Engineering Design Tools and Techniques,
D.2.11 Software Engineering Software Architectures,
D.3.4 Programming Languages Processors},
ee = {https://edoc2019.sciencesconf.org/},
contact = {Vladimir Yussupov yussupov@iaas.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {Function-as-a-Service (FaaS) is an emerging cloud service model that enables
composing applications using arbitrary, small, and event-driven code snippets
managed by cloud providers and that can be scaled to zero. The scalability
properties of FaaS look attractive for handling rare or unexpected high loads
that affect only particular functionalities of the application. However,
deciding on the component granularity upfront or reengineering the architecture
of an entire application for rare workloads is often a very difficult challenge
or even infeasible. In this work, we introduce a method that prepares annotated
functionalities for handling rare workloads by automatically extracting them
from the source code of the application and additionally deploying them as FaaS
functions, while keeping the original application's functionalities and
architecture unchanged. In this way, the benefits of FaaS can be leveraged
without the need to reengineer the application only for rare cases. We validate
our method by means of a prototype, evaluate its feasibility in a set of
experiments, and discuss limitations and future work.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-36&engl=0}
}
@inproceedings {INPROC-2019-35,
author = {Ghareeb Falazi and Michael Hahn and Uwe Breitenb{\"u}cher and Frank Leymann and Vladimir Yussupov},
title = {{Process-Based Composition of Permissioned and Permissionless Blockchain Smart Contracts}},
booktitle = {Proceedings of the 2019 IEEE 23rd International Enterprise Distributed Object Computing Conference (EDOC 2019)},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {77--87},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2019},
doi = {10.1109/EDOC.2019.00019},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
D.2.2 Software Engineering Design Tools and Techniques,
D.2.11 Software Engineering Software Architectures},
ee = {https://edoc2019.sciencesconf.org/},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {Blockchains are distributed systems that facilitate the interaction of
autonomous entities with limited mutual trust. Many of them support
transactional applications known as smart contracts, which access and modify
the shared world state. Permissionless blockchains are completely decentralized
and do not require mutual trust between interacting peers, but at the expense
of having low performance and limited data confidentiality capabilities. On the
other hand, permissioned blockchains solve these issues, but sacrifice complete
decentralization and involve more trust assumptions. Therefore, there is no
single blockchain system suitable for all use-cases. However, this becomes a
serious integration challenge for enterprises that need to interact with
multiple permissioned and permissionless blockchains in the same context. To
facilitate this, we propose an approach that enables composing smart contract
functions of various permissioned and permissionless blockchain systems by
providing the ability to invoke them directly from business process models
using a new task type. To keep this task blockchain-agnostic, we designed a
generic technique to identify smart contract functions, as well as a generic
metric to describe the degree-of-confidence in the finality of blockchain
transactions. Thereby, the proposed approach extends our previous work,
BlockME, which provides business modeling extensions only suitable for
interacting with permissionless blockchains. To validate the practical
feasibility of our approach, we provide a detailed system architecture and a
prototypical implementation supporting multiple blockchains.
Keywords: blockchains, business process management, permissioned blockchains,
smart contract composition, blockchain access layer, BlockME2},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-35&engl=0}
}
@inproceedings {INPROC-2018-40,
author = {Michael Hahn and Uwe Breitenb{\"u}cher and Frank Leymann and Michael Wurster and Vladimir Yussupov},
title = {{Modeling Data Transformations in Data-Aware Service Choreographies}},
booktitle = {Proceedings of the IEEE 22nd International Enterprise Distributed Object Computing Conference (EDOC)},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {28--34},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2018},
doi = {10.1109/EDOC.2018.00014},
language = {Englisch},
cr-category = {H.4.1 Office Automation,
C.2.4 Distributed Systems},
contact = {Michael Hahn: michael.hahn@iaas-uni.stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {The importance of data is steadily increasing in the domain of business process
management due to recent advances in data science, IoT, and Big Data. To
reflect this paradigm shift towards data-awareness in service choreographies,
we introduced the notion of data-aware choreographies based on concepts for
Transparent Data Exchange (TraDE) in our previous works. The goal is to
simplify the modeling of business-relevant data and its exchange in
choreography models while increasing their run time flexibility. To further
improve and simplify the modeling of data-related aspects in service
choreographies, in this paper, we focus on the extension of our TraDE concepts
to support the modeling of data transformations in service choreographies. Such
data transformation capabilities are of dire need to mediate between different
data formats, structures and representations of the collaborating participants
within service choreographies. Therefore, the paper presents a modeling
extension as means for specifying and executing heterogeneous data
transformations in service choreographies based on our TraDE concepts.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-40&engl=0}
}
@inproceedings {INPROC-2018-39,
author = {Michael Hahn and Uwe Breitenb{\"u}cher and Frank Leymann and Vladimir Yussupov},
title = {{Transparent Execution of Data Transformations in Data-Aware Service Choreographies}},
booktitle = {On the Move to Meaningful Internet Systems. OTM 2018 Conferences (CoopIS 2018)},
publisher = {Springer International Publishing AG},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Lecture Notes in Computer Science},
volume = {11230},
pages = {117--137},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2018},
isbn = {978-3-030-02671-4},
doi = {10.1007/978-3-030-02671-4_7},
keywords = {Data-aware Choreographies; Data Transformation; TraDE},
language = {Englisch},
cr-category = {H.4.1 Office Automation,
C.2.4 Distributed Systems},
contact = {Michael Hahn: michael.hahn@iaas.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {Due to recent advances in data science, IoT, and Big Data, the importance of
data is steadily increasing in the domain of business process management.
Service choreographies provide means to model complex conversations between
collaborating parties from a global viewpoint. However, the involved parties
often rely on their own data formats. To still enable the interaction between
them within choreographies, the underlying business data has to be transformed
between the different data formats. The state-of-the-art in modeling such data
transformations as additional tasks in choreography models is error-prone, time
consuming and pollutes the models with functionality that is not relevant from
a business perspective but technically required. As a first step to tackle
these issues, we introduced in previous works a data transformation modeling
extension for defining data transformations on the level of choreography models
independent of their control flow as well as concrete technologies or tools.
However, this modeling extension is not executable yet. Therefore, this paper
presents an approach and a supporting integration middleware which enable to
provide and execute data transformation implementations based on various
technologies or tools in a generic and technology-independent manner to realize
an end-to-end support for modeling and execution of data transformations in
service choreographies.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-39&engl=0}
}
@inproceedings {INPROC-2018-38,
author = {Andreas Liebing and Lutz Ashauer and Uwe Breitenb{\"u}cher and Thomas G{\"u}nther and Michael Hahn and K{\'a}lm{\'a}n K{\'e}pes and Oliver Kopp and Frank Leymann and Bernhard Mitschang and Ana C. Franco da Silva and Ronald Steinke},
title = {{The SmartOrchestra Platform: A Configurable Smart Service Platform for IoT Systems}},
booktitle = {Papers from the 12th Advanced Summer School on Service-Oriented Computing (SummerSoC 2018)},
publisher = {IBM Research Division},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {14--21},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2018},
keywords = {SmartOrchestra Platform; Smart Services; Cyber-Physical Systems; Internet of Things},
language = {Englisch},
cr-category = {K.6 Management of Computing and Information Systems,
D.2.7 Software Engineering Distribution, Maintenance, and Enhancement,
D.2.12 Software Engineering Interoperability},
ee = {https://www.2018.summersoc.eu/},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Anwendersoftware;
Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {The Internet of Things is growing rapidly while still missing a universal
operat-ing and management platform for multiple diverse use cases. Such a
platform should provide all necessary functionalities and the underlying
infrastructure for the setup, execution and composition of Smart Services. The
concept of Smart Services enables the connection and integration of
cyber-physical systems (CPS) and technologies (i.e., sensors and actuators)
with business-related applications and services. Therefore, the SmartOrchestra
Platform provides an open and standards-based service platform for the
utilization of public administrative and business-related Smart Services. It
combines the features of an operating plat-form, a marketplace, a broker, and a
notary for a cloud-based operation of Smart Services. Thus, users of
cyber-physical systems are free to choose their control applications, no matter
what device they are using (e.g., smartphone, tablet or personal computer) and
they also become independent of the manufacturers’ software. This will enable
new business opportunities for different stakeholders in the market and allows
flexibly composing Smart Services.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-38&engl=0}
}
@inproceedings {INPROC-2017-54,
author = {Michael Hahn and Uwe Breitenb{\"u}cher and Frank Leymann and Andreas Wei{\ss}},
title = {{TraDE - A Transparent Data Exchange Middleware for Service Choreographies}},
booktitle = {On the Move to Meaningful Internet Systems. OTM 2017 Conferences: Confederated International Conferences: CoopIS, C\&TC, and ODBASE 2017, Rhodes, Greece, October 23-27, 2017, Proceedings, Part I},
editor = {Herv{\'e} Panetto and Christophe Debruyne and Walid Gaaloul and Mike Papazoglou and Adrian Paschke and Claudio Agostino Ardagna and Robert Meersman},
publisher = {Springer International Publishing},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Lecture Notes in Computer Science},
volume = {10573},
pages = {252--270},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2017},
isbn = {978-3-319-69462-7},
doi = {10.1007/978-3-319-69462-7_16},
keywords = {Service choreographies; Data-awareness; Cross-partner data flow; Transparent data exchange; BPM},
language = {Englisch},
cr-category = {H.4.1 Office Automation,
C.2.4 Distributed Systems},
contact = {Michael Hahn: michael.hahn@iaas.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {Due to recent advances in data science the importance of data is increasing
also in the domain of business process management. To reflect the paradigm
shift towards data-awareness in service compositions, in previous work, we
introduced the notion of data-aware choreographies through cross-partner data
objects and cross-partner data flows as means to increase run time flexibility
while reducing the complexity of modeling data flows in service choreographies.
In this paper, we focus on the required run time environment to execute such
data-aware choreographies through a new Transparent Data Exchange (TraDE)
Middleware. The contributions of this paper are a choreography
language-independent metamodel and an architecture for such a middleware.
Furthermore, we evaluated our concepts and TraDE Middleware prototype by
conducting a performance evaluation that compares our approach for
cross-partner data flows with the classical exchange of data within service
choreographies through messages. The evaluation results already show some
valuable performance improvements when applying our TraDE concepts.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-54&engl=0}
}
@inproceedings {INPROC-2016-38,
author = {Andreas Wei{\ss} and Vasilios Andrikopoulos and Santiago G{\'o}mez S{\'a}ez and Michael Hahn and Dimka Karastoyanova},
title = {{ChorSystem: A Message-Based System for the Life Cycle Management of Choreographies}},
booktitle = {On the Move to Meaningful Internet Systems: OTM 2016 Conferences: Confederated International Conferences: CoopIS, C\&TC, and ODBASE 2016, Rhodes, Greece, October 24-28, 2016, Proceedings},
editor = {Christophe Debruyne and Herv{\'e} Panetto and Robert Meersman and Tharam Dillon and Eva K{\"u}hn and Declan O'Sullivan and Claudio Agostino Ardagna},
publisher = {Springer International Publishing},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {503--521},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2016},
doi = {10.1007/978-3-319-48472-3_30},
keywords = {Collaborative Dynamic Complex (CDC) Systems; Choreography Life Cycle Management; Flexible Choreographies},
language = {Englisch},
cr-category = {H.4.1 Office Automation},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2016-38/INPROC-2016-38.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {Service choreographies are commonly used as the means for enabling
inter-organizational collaboration by providing a global view on the message
exchange between involved participants. Choreographies are ideal for a number
of application domains that are classi ed under the Collaborative, Dynamic \&
Complex (CDC) systems area. System users in these application domains require
facilities to control the execution of a choreography instance such as
suspending, resuming or terminating, and thus actively control its life cycle.
We support this requirement by introducing the ChorSystem, a system capable of
managing the complete life cycle of choreographies from choreography modeling,
through deployment, to execution and monitoring. The performance evaluation of
the life cycle operations shows that the ChorSystem introduces an acceptable
performance overhead compared to purely script-based scenarios, while gaining
the abilities to control the choreography life cycle.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-38&engl=0}
}
@inproceedings {INPROC-2016-26,
author = {Michael Hahn and Dimka Karastoyanova and Frank Leymann},
title = {{A Management Life Cycle for Data-Aware Service Choreographies}},
booktitle = {Proceedings of the Twenty-Third International Conference on Web Services (ICWS 2016), San Francisco, CA, USA, 2016},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {364--371},
type = {Konferenz-Beitrag},
month = {September},
year = {2016},
doi = {10.1109/ICWS.2016.54},
keywords = {Choreography Management Life Cycle; Data Flow Optimization; Service Choreographies; Transparent Data Exchange},
language = {Englisch},
cr-category = {H.4.1 Office Automation,
C.2.4 Distributed Systems},
contact = {Michael Hahn: michael.hahn@iaas.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {This work is motivated by the increasing importance and business value of data
in the fields of business process management, scientific workflows as a field
in eScience, and Internet of Things, all of which profiting from the recent
advances in data science and Big data. We introduce a management life cycle
that renders data as first-class citizen in service choreographies and defines
the functions and artifacts necessary for enabling transparent and efficient
data exchange among choreography participants. The inherent goal of the life
cycle, functions and artifacts is to help decouple the data flow, data exchange
and management from the control flow in service compositions and
choreographies. This decoupling enables peer-to-peer data exchange in
choreographies and provides the means for more sophisticated data management
and exchange, as well as data exchange and provisioning optimization.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-26&engl=0}
}
@inproceedings {INPROC-2016-04,
author = {Michael Hahn and Dimka Karastoyanova and Frank Leymann},
title = {{Data-Aware Service Choreographies through Transparent Data Exchange}},
booktitle = {Proceedings of the 16th International Conference on Web Engineering (ICWE'16)},
publisher = {Springer International Publishing},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Lecture Notes in Computer Science (LNCS)},
volume = {9671},
pages = {357--364},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2016},
doi = {10.1007/978-3-319-38791-8_20},
keywords = {Service Choreographies; Transparent Data Exchange; Decentralized Data Flow; Data Flow Optimization},
language = {Englisch},
cr-category = {H.4.1 Office Automation,
C.2.4 Distributed Systems},
contact = {Michael Hahn: michael.hahn@iaas.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {Our focus in this paper is on enabling the decoupling of data flow, data
exchange and management from the control flow in service compositions and
choreographies through novel middleware abstractions and realization. This
allows us to perform the data flow of choreographies in a peer-to-peer fashion
decoupled from their control flow. Our work is motivated by the increasing
importance and business value of data in the fields of business process
management, scientific workflows and the Internet of Things, all of which
profiting from the recent advances in data science and Big data. Our approach
comprises an application life cycle that inherently introduces data exchange
and management as a first-class citizen and defines the functions and artifacts
necessary for enabling transparent data exchange. Moreover, we present an
architecture of the supporting system that contains the Transparent Data
Exchange middleware which enables the data exchange and management on behalf of
service choreographies and provides methods for the optimization of the data
exchange during the execution of service choreographies.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-04&engl=0}
}
@inproceedings {INPROC-2016-02,
author = {Vasilios Andrikopoulos and Marina Bitsaki and Santiago G{\'o}mez S{\'a}ez and Michael Hahn and Dimka Karastoyanova and Giorgios Koutras and Alina Psycharaki},
title = {{Evaluating the Effect of Utility-based Decision Making in Collective Adaptive Systems}},
booktitle = {Proceedings of the 6th International Conference on Cloud Computing and Service Science (CLOSER 2016)},
address = {Rome, Italy},
publisher = {SciTePress},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {April},
year = {2016},
language = {Deutsch},
cr-category = {D.2.0 Software Engineering General,
D.2.11 Software Engineering Software Architectures,
D.2.12 Software Engineering Interoperability},
contact = {Vasilios Andrikopoulos: andrikopoulos@iaas.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {Utility, defined as the perceived satisfaction with a service, provides the
ideal means for decision making on the level of individual entities and
collectives participating in a large-scale dynamic system. Previous works have
already introduced the concept into the area of collective adaptive systems,
and have discussed what is the necessary infrastructure to support the
realization of the involved theoretical concepts into actual decision making.
In this work we focus on two aspects. First, we provide a concrete utility
model for a case study that is part of a larger research project. Second, we
incorporate this model into our implementation of the proposed architecture.
More importantly, we design and execute an experiment that aims to empirically
evaluate the use of utility for decision making by comparing it against simpler
decision making mechanisms.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-02&engl=0}
}
@inproceedings {INPROC-2015-40,
author = {Andreas Wei{\ss} and Vasilios Andrikopoulos and Michael Hahn and Dimka Karastoyanova},
title = {{Rewinding and Repeating Scientific Choreographies}},
booktitle = {On the Move to Meaningful Internet Systems: OTM 2015 Conferences},
editor = {H. Panetto et al. C. Debruyne},
publisher = {Springer},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {337--347},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2015},
doi = {10.1007/978-3-319-26148-5_22},
keywords = {Ad Hoc changes; Choreography; Workflow; Flexibility},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H.4.1 Office Automation},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {Scientists that use the workflow paradigm for the enactment of scientific
experiments need support for trial-and-error modeling, as well as flexibility
mechanisms that enable the ad hoc repetition of workflow logic for the
convergence of results or error handling. Towards this goal, in this paper we
introduce the facilities to repeat partially or completely running
choreographies on demand. Choreographies are interesting for the scientific
workflow community because so-called multi-scale/field (multi-*) experiments
can be modeled and enacted as choreographies of scientific workflows. A
prerequisite for choreography repetition is the rewinding of the involved
participant instances to a previous state. For this purpose, we define a formal
model representing choreography models and their instances as well as a concept
to repeat choreography logic. Furthermore, we provide an algorithm for
determining the rewinding points in each involved participant instance.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-40&engl=0}
}
@inproceedings {INPROC-2015-35,
author = {Santiago G{\'o}mez S{\'a}ez and Vasilios Andrikopoulos and Michael Hahn and Dimka Karastoyanova and Andreas Wei{\ss}},
title = {{Enabling Reusable and Adaptive Modeling, Provisioning \& Execution of BPEL Processes}},
booktitle = {Proceedings of the 8th International Conference on Service-Oriented Computing and Applications (SOCA'15)},
address = {Rome, Italy},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2015},
language = {Englisch},
cr-category = {H.4.1 Office Automation,
C.2.4 Distributed Systems,
D.2.11 Software Engineering Software Architectures},
contact = {Santiago G{\'o}mez S{\'a}ez: gomez-saez@iaas.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {The Business Process Execution Language (BPEL) is a well established language
for the definition of process models as service orchestrations. Service
orchestrations are used in conjunction with service choreographies in order to
create distributed, complex service-based applications. An important
requirement for such applications is the need for flexibility during both their
modeling and their execution. This work builds on this need by proposing an
extension of BPEL in order to allow the definition of abstract constructs on
the level of executable process models. Such constructs can be refined to
concrete activities at any time, enabling the reuse of existing models and the
dynamic adaptation to changing requirements. The design and implementation of
the language extension, as well as that of the supporting environment required
for the modeling, provisioning, and execution of such process models is further
discussed. A case study on a city-wide public transportation system offers the
means for an evaluation of the proposed approach.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-35&engl=0}
}
@inproceedings {INPROC-2015-18,
author = {Andreas Wei{\ss} and Vasilios Andrikopoulos and Michael Hahn and Dimka Karastoyanova},
title = {{Enabling the Extraction and Insertion of Reusable Choreography Fragments}},
booktitle = {Proceedings of the 22nd IEEE International Conference on Web Services},
address = {New York},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {686--694},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2015},
doi = {10.1109/ICWS.2015.96},
language = {Englisch},
cr-category = {H.4.1 Office Automation},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {Reuse of service orchestrations or service compositions is extensively studied
in the literature of process modeling. Sub-processes, process templates,
process variants, and process reference models are employed as reusable
elements for these purposes. The concept of process fragments has been
previously introduced in order to capture parts of a process model and store
them for later reuse. However, similar efforts on facilitating the reuse of
processes that cross the boundaries of organizations expressed as service
choreographies are not available yet. In this paper, we introduce the concept
of choreography fragments as reusable elements for service choreography
modeling. Choreography fragments can be extracted from choreography models,
adapted, stored, and later inserted into new models. Based on a formal model
for choreography fragments, we define methods and algorithms for the extraction
and insertion of fragments from and into service choreographies. We then
discuss an experimental and proof-of-concept evaluation of our proposal.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-18&engl=0}
}
@inproceedings {INPROC-2015-14,
author = {Santiago G{\'o}mez S{\'a}ez and Vasilios Andrikopoulos and Michael Hahn and Dimka Karastoyanova and Frank Leymann and Marigianna Skouradaki and Karolina Vukojevic-Haupt},
title = {{Performance and Cost Evaluation for the Migration of a Scientific Workflow Infrastructure to the Cloud}},
booktitle = {Proceedings of the 5th International Conference on Cloud Computing and Service Science (CLOSER 2015)},
publisher = {SciTePress},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {352--361},
type = {Konferenz-Beitrag},
month = {Mai},
year = {2015},
keywords = {Workflow Simulation; eScience; IaaS; Performance Evaluation; Cost Evaluation; Cloud Migration},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
D.2.8 Software Engineering Metrics,
D.2.11 Software Engineering Software Architectures},
contact = {Santiago G{\'o}mez S{\'a}ez: santiago.gomez-saez@iaas.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {The success of the Cloud computing paradigm, together with the increase of
Cloud providers and optimized Infrastructure-as-a-Service (IaaS) offerings have
contributed to a raise in the number of research and industry communities that
are strong supporters of migrating and running their applications in the Cloud.
Focusing on eScience simulation-based applications, scientific workflows have
been widely adopted in the last years, and the scientific workflow management
systems have become strong candidates for being migrated to the Cloud. In this
research work we aim at empirically evaluating multiple Cloud providers and
their corresponding optimized and non-optimized IaaS offerings with respect to
their offered performance, and its impact on the incurred monetary costs when
migrating and executing a workflow-based simulation environment. The
experiments show significant performance improvements and reduced monetary
costs when executing the simulation environment in off-premise Clouds.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-14&engl=0}
}
@inproceedings {INPROC-2015-07,
author = {Andreas Wei{\ss} and Vasilios Andrikopoulos and Michael Hahn and Dimka Karastoyanova},
title = {{Fostering Reuse in Choreography Modeling Through Choreography Fragments}},
booktitle = {Proceedings of the 17th International Conference on Enterprise Information Systems ICEIS 2015},
publisher = {SciTePress},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {28--36},
type = {Konferenz-Beitrag},
month = {April},
year = {2015},
doi = {10.5220/0005342000280036},
keywords = {Choreography; Choreography Fragment; Choreography Fragment Pattern; Choreography Modeling; Reuse},
language = {Englisch},
cr-category = {H.4.1 Office Automation},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {The concept of reuse in process models is extensively studied in the
literature. Sub-processes, process templates, process variants, and process
reference models are employed as reusable elements for process modeling.
Additionally, the notion of process fragments has been introduced to capture
parts of a process model and store them for later reuse. In contrast, concepts
for reuse of processes that cross the boundaries of organizations, i.e.,
choreographies, have not yet been studied in the appropriate level of detail.
In this paper, we introduce the concept of choreography fragments as reusable
elements for choreography modeling. Choreography fragments can be extracted
from choreography models, adapted, stored, and inserted into new models. We
provide a formal model for choreography fragments and identify a set of
patterns constituting frequently occurring meaningful choreography fragments.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-07&engl=0}
}
@inproceedings {INPROC-2015-04,
author = {Marigianna Skouradaki and Katharina Goerlach and Michael Hahn and Frank Leymann},
title = {{Application of Sub-Graph Isomorphism to Extract Reoccurring Structures from BPMN 2.0 Process Models}},
booktitle = {9th International IEEE Symposium on Service-Oriented System Engineering : SOSE 2015; San Francisco Bay, USA, March 30 - 3, 2015},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {April},
year = {2015},
keywords = {structural similarities; process models; BPMN 2.0; process fragments; subgraph isomorphism},
language = {Englisch},
cr-category = {I.2.8 Problem Solving, Control Methods, and Search,
F.2.2 Nonnumerical Algorithms and Problems,
D.2.9 Software Engineering Management},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {The state-of-art approaches in structural similarities of process models base
their operations on behavioral data and text semantics. These data is usually
missing from mock-up or obfuscated process models. This fact makes it
complicated to apply current approaches on these types of models. We examine
the problem of the automated detection of re-occurring structures in a
collection of process models, when text semantics or behavioral data are
missing. This problem is a case of (sub)graph isomorphism, which is mentioned
as NP-complete in the literature. Since the process models are very special
types of attributed directed graphs we are able to develop an approach that
runs with logarithmic complexity. In this work we set the theoretical basis,
develop a configurable approach for the detection of re-occurring structures in
any process models collection, and validate it against a set of BPMN 2.0
models. We define two execution scenarios and discuss the relation of the
execution times with the complexity of the comparisons. Finally, we analyze the
detected structures, and propose the configurations that lead to optimal
results.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-04&engl=0}
}
@inproceedings {INPROC-2014-71,
author = {Michael Hahn and Santiago G{\'o}mez S{\'a}ez and Vasilios Andrikopoulos and Dimka Karastoyanova and Frank Leymann},
title = {{Development and Evaluation of a Multi-tenant Service Middleware PaaS Solution}},
booktitle = {Proceedings of the 7th International Conference on Utility and Cloud Computing (UCC 2014)},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {278--287},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2014},
doi = {10.1109/UCC.2014.37},
keywords = {Multi-tenancy; Cloud middleware; PaaS; Performance Evaluation},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H.4.1 Office Automation},
contact = {Michael Hahn: michael.hahn@iaas.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {In many modern systems, applications or services are realized as compositions
of multiple existing services that can be enacted by Service Composition
Engines (SCEs), which provide the required functionality to enable their
definition and execution. SCEs typically use the capabilities of an Enterprise
Service Bus (ESB) which serves as the messaging hub between the composed
services aiming at ensuring their integration. Together, an SCE and ESB
solution comprise the service middleware required for the definition and
execution of service-based composite applications. Offering a service
middleware solution as a service creates a PaaS offering that allows the
service consumers to share the service middleware solution in a multi-tenant
manner. However, multi-tenancy support for service middleware solutions remains
an open issue. For this purpose, in this work we introduce a general
architecture for the realization of a multi-tenant service middleware PaaS
solution. This architecture is prototypically realized based on open-source,
multi-tenant ESB and SCE solutions. The resulting service middleware provides
configurability for service compositions, tenant-aware messaging, and
tenant-based administration and management of the SCE and the ESB. We also
present an empirical evaluation of the multi-tenant service middleware with
focus on the SCE. The results of these experiments show a performance
degradation within acceptable limits when scaling the number of tenants and
tenant users.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-71&engl=0}
}
@inproceedings {INPROC-2014-69,
author = {Michael Hahn and Santiago G{\'o}mez S{\'a}ez and Vasilios Andrikopoulos and Dimka Karastoyanova and Frank Leymann},
title = {{SCE^MT: A Multi-tenant Service Composition Engine}},
booktitle = {Proceedings of the 7th International Conference on Service-Oriented Computing and Applications (SOCA'14)},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {89--96},
type = {Konferenz-Beitrag},
month = {November},
year = {2014},
doi = {10.1109/SOCA.2014.9},
keywords = {Multi-tenancy; Service Composition Engine; Cloud middleware; Performance Evaluation},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
contact = {Michael Hahn: michael.hahn@iaas.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {The support of multi-tenancy is an essential requirement for leveraging the
full capacity of Cloud computing. Multi-tenancy enables service providers to
maximize the utilization of their infrastructure and to reduce the servicing
costs per customer, thus indirectly benefiting also the customers. In addition,
it allows both providers and consumers to reap the advantages of Cloud-based
applications configurable for the needs of different tenants. Nowadays, new
applications or services are typically compositions of multiple existing
services. Service Composition Engines (SCEs) provide the required functionality
to enable the definition and execution of such compositions. Multi-tenancy on
the level of SCEs allows for both process model, as well as underlying
infrastructure sharing. Towards the goal of enabling multi-tenancy of SCEs, in
this paper, we investigate the requirements and define a general architecture
for the realization of a multi-tenant SCE solution. This architecture is
prototypically realized based on an open-source SCE implementation and
integrated into an existing multi-tenant aware Enterprise Service Bus (ESB).
The performance evaluation of our prototype shows promising results in terms of
the degradation introduced due to processing and communication overhead.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-69&engl=0}
}
@inproceedings {INPROC-2014-60,
author = {Andreas Wei{\ss} and Santiago G{\'o}mez S{\'a}ez and Michael Hahn and Dimka Karastoyanova},
title = {{Approach and Refinement Strategies for Flexible Choreography Enactment}},
booktitle = {22nd International Conference on Cooperative Information Systems (CoopIS 2014)},
editor = {H. Panetto et al. R. Meersman},
publisher = {Springer Berlin Heidelberg},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {93--111},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2014},
doi = {10.1007/978-3-662-45563-0_6},
keywords = {Process Flexibility, Choreography Flexibility, Refinement Strategies, Late Modeling, Late Selection, Process Fragments},
language = {Englisch},
cr-category = {H.4.1 Office Automation},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {Collaborative, Dynamic \& Complex (CDC) systems such as adaptive pervasive
systems, eScience applications, and complex business systems inherently require
modeling and run time exibility. Since domain problems in CDC systems are
expressed as service choreographies and enacted by service orchestrations, we
propose an approach introducing placeholder modeling constructs usable both on
the level of choreographies and orchestrations, and a classi cation of
strategies for their re nement to executable work ows. These abstract modeling
constructs allow deferring the modeling decisions to later points in the life
cycle of choreographies. This supports run time scenarios such as incorporating
new participants into a choreography after its enactment has started or
enhancing the process logic of some of the participants. We provide a
prototypical implementation of the approach and evaluate it by means of a case
study.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-60&engl=0}
}
@inproceedings {INPROC-2014-42,
author = {Michael Hahn and Dimka Karastoyanova},
title = {{Configurable and Collaborative Scientific Workflows}},
booktitle = {Workshop on Simulation Technology: Systems for Data Intensive Simulations (SimTech(at)GI) in Conjunction with INFORMATIK 2014},
publisher = {Gesellschaft f{\"u}r Informatik e.V. (GI)},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Lecture Notes in Informatics (LNI)},
volume = {P-232},
pages = {125--136},
type = {Workshop-Beitrag},
month = {September},
year = {2014},
language = {Englisch},
cr-category = {H.4.1 Office Automation},
contact = {Michael Hahn: michael.hahn@iaas.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {The use of workflows to support and realize computer simulations, experiments
and calculations is well-accepted in the e-Science domain. The different tasks
and the parameters of the simulation are therefore specified in workflow
models. Scientists typically work in a trial-and-error manner which means they
do not know how the final workflow of a simulation has to look like. Therefore,
they use a maybe insufficient workflow model as a basis and try to improve this
model over multiple iterations to get a better approximation to the problem to
solve. So in each iteration multiple trials are based on different variants of
the same workflow model. Towards the goal of building variants of workflow
models and enabling the reuse of existing scientific workflows in a controlled
and well-defined manner, in this paper, we identify how configurable workflow
models will support scientists to customize existing workflow models by their
configuration. Therefore, we introduce possible configuration options for
scientific workflows and how scientists can specify them. Furthermore, we show
how configurable workflow models are a first step towards enabling the
collaboration among scientists in creating scientific workflows.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-42&engl=0}
}
@inproceedings {INPROC-2012-29,
author = {Mirko Sonntag and Michael Hahn and Dimka Karastoyanova},
title = {{Mayflower - Explorative Modeling of Scientific Workflows with BPEL}},
booktitle = {Proceedings of the Demo Track of the 10th International Conference on Business Process Management (BPM 2012), CEUR Workshop Proceedings, 2012},
publisher = {CEUR Workshop Proceedings},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--5},
type = {Workshop-Beitrag},
month = {September},
year = {2012},
keywords = {Scientific workflows; Model-as-you-go; SOA; BPEL},
language = {Englisch},
cr-category = {H.4.1 Office Automation,
I.6.5 Model Development,
D.2.2 Software Engineering Design Tools and Techniques},
ee = {http://www.ceur-ws.org},
contact = {sonntag@iaas.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {Using workflows for scientific calculations, experiments and simulations has
been a success story in many cases. Unfortunately, most of the existing
scientific workflow systems implement proprietary, non-standardized workflow
languages, not taking advantage of the achievements of the conventional
business workflow technology. It is only natural to combine these two research
branches in order to harness the strengths of both. In this demonstration, we
present Mayflower, a workflow environment that enables scientists to model
workflows on the fly using extended business workflow technology. It supports
the typical trial-and-error approach scientists follow when developing their
experiments, computations or simulations and provides scientist with all
crucial characteristics of the workflow technology. Additionally, beneficial to
the business stakeholders, Mayflower brings additional simplification in
workflow de-velopment and debugging.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-29&engl=0}
}
@inproceedings {INPROC-2012-16,
author = {David Schumm and Dimitrios Dentsas and Michael Hahn and Dimka Karastoyanova and Frank Leymann and Mirko Sonntag},
title = {{Web Service Composition Reuse through Shared Process Fragment Libraries}},
booktitle = {Proceedings of the 12th International Conference on Web Engineering (ICWE 2012 Demos)},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Lecture Notes in Computer Science},
pages = {1--4},
type = {Workshop-Beitrag},
month = {Juli},
year = {2012},
doi = {10.1007/978-3-642-31753-8_53},
keywords = {Process Reuse; Service Composition; Web Services; BPEL; Process Fragments.},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
D.2.2 Software Engineering Design Tools and Techniques,
H.3.5 Online Information Services,
H.4.1 Office Automation},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {More and more application functionality is provided for use over corporate and
public networks. Standardized technology stacks, like Web services, provide
abstraction from the internal implementation. Coarse-grained units of Web
service composition logic can be made reusable by capturing it as ‘process
fragment’. Such fragments can be shared over the Web to simplify and accelerate
development of process-based service compositions. In this demonstration, we
present a framework consisting of an Eclipse-based process design environment
that is integrated with a Web-based process fragment library. The framework
enables extracting process fragments, publishing and sharing them on the Web,
as well as search, retrieval, and their reuse in a given process. Process
fragments can be shared with others using a Web frontend or through a plug-in
within the process design environment which is building on Web service
technology.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-16&engl=0}
}
@article {ART-2019-02,
author = {Ghareeb Falazi and Michael Hahn and Uwe Breitenb{\"u}cher and Frank Leymann},
title = {{Modeling and execution of blockchain-aware business processes}},
journal = {SICS Software-Intensive Cyber-Physical Systems},
address = {Heidelberg},
publisher = {Springer Berlin Heidelberg},
pages = {1--12},
type = {Artikel in Zeitschrift},
month = {Februar},
year = {2019},
doi = {10.1007/s00450-019-00399-5},
keywords = {Blockchains; Business Process Management Systems; BPMN; Modeling; BlockME; Blockchain Access Layer; BAL; BPMN Extension},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
D.2.2 Software Engineering Design Tools and Techniques,
D.2.11 Software Engineering Software Architectures,
D.2.12 Software Engineering Interoperability},
contact = {Ghareeb Falazi ghareeb.falazi@iaas.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {The blockchain is an emerging technology that allows multiple parties to agree
on a common state without the need for trusted intermediaries. Moreover,
business process technology streamlines the automation of inter- and
intra-organizational processes while cutting-down on costs. With the new
business opportunities provided by blockchains, it becomes vital to combine
both technologies to allow the modeling and execution of blockchain-based
interactions within business processes. However, the existing business process
modeling languages lack support to intuitively model the various interactions
with blockchains. In this paper we address this issue by proposing a business
process modeling extension that captures the particularities of blockchains. We
also show how to transform the proposed constructs into standard-compliant
models, and we present an integration architecture that allows external
applications, to communicate with the blockchains. Finally, we validate our
approach by providing a prototypical implementation that proves its practical
feasibility.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2019-02&engl=0}
}
@article {ART-2017-12,
author = {Andreas Wei{\ss} and Vasilios Andrikopoulos and Michael Hahn and Dimka Karastoyanova},
title = {{Model-as-you-go for Choreographies: Rewinding and Repeating Scientific Choreographies}},
journal = {IEEE Transactions on Services Computing},
publisher = {IEEE},
volume = {PP},
number = {99},
pages = {1--1},
type = {Artikel in Zeitschrift},
month = {Juli},
year = {2017},
doi = {10.1109/TSC.2017.2732988},
keywords = {Ad Hoc Changes; Choreography Re-execution and Iteration; Choreography Rewinding; Flexible Choreography; Multi-* Experiment; Workflow},
language = {Englisch},
cr-category = {H.4.1 Office Automation},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2017-12/ART-2017-12.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {Scientists are increasingly using the workflow technology as a means for
modeling and execution of scientific experiments. Despite being a very powerful
paradigm workflows still lack support for trial-and-error modeling, as well as
flexibility mechanisms that enable the ad hoc repetition of experiment logic to
enable, for example, the convergence of results or to handle errors. In this
respect, in our work on enabling multi-scale/field (multi-*) experiments using
choreographies of scientific workflows, we contribute a method comprising all
necessary steps to conduct the repetition of choreography logic across all
workflow instances participating in a multi-* experiment. To realize the
method, we contribute i) a formal model representing choreography models and
instances, including the re-execute and iterate operations for choreographies,
and based on it ii) algorithms for determining the rewinding points, i.e. the
activity instances where the rewinding has to stop and iii) enable the actual
rewinding to a previous execution state and repetition of the choreography. We
present the implementation of our approach in a message-based, service-oriented
system that allows scientists to model, control, and execute scientific
choreographies as well as perform the rewinding and repeating of choreography
logic. We also provide an evaluation of the performance of our approach.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2017-12&engl=0}
}
@article {ART-2017-08,
author = {Michael Hahn and Uwe Breitenb{\"u}cher and Oliver Kopp and Frank Leymann},
title = {{Modeling and execution of data-aware choreographies: an overview}},
journal = {Computer Science - Research and Development},
publisher = {Springer Berlin Heidelberg},
pages = {1--12},
type = {Artikel in Zeitschrift},
month = {September},
year = {2017},
issn = {1865-2042},
doi = {10.1007/s00450-017-0387-y},
keywords = {Service Choreographies; Data-awareness; Cross-Partner Data Flow; Transparent Data Exchange},
language = {Englisch},
cr-category = {H.4.1 Office Automation,
C.2.4 Distributed Systems},
contact = {Michael Hahn: michael.hahn@iaas.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {Due to recent advances in data science and Big Data the importance of data is
increasing. Although service choreographies provide means to specify complex
conversations between multiple interacting parties from a global perspective
and in a technology-agnostic manner, they do not fully reflect the paradigm
shift towards data-awareness at the moment. In this paper, we discuss current
shortcomings such as missing support for data flow across services and a
choreography data contract all interacting parties agree on. This results in
more complex and rigid choreography models, making them also less flexible
regarding their data perspective during run time. The main contribution is our
approach for modeling and execution of data-aware service choreographies
towards increasing the level of data awareness in choreographies.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2017-08&engl=0}
}
@inbook {INBOOK-2016-02,
author = {Santiago G{\'o}mez S{\'a}ez and Vasilios Andrikopoulos and Michael Hahn and Dimka Karastoyanova and Frank Leymann and Marigianna Skouradaki and Karolina Vukojevic-Haupt},
title = {{Performance and Cost Trade-Off in IaaS Environments: A Scientific Workflow Simulation Environment Case Study}},
series = {Cloud Computing and Services Science},
publisher = {Springer},
series = {Communications in Computer and Information Science},
volume = {581},
pages = {153--170},
type = {Beitrag in Buch},
month = {Februar},
year = {2016},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
D.2.8 Software Engineering Metrics,
D.2.11 Software Engineering Software Architectures},
contact = {Santiago G{\'o}mez S{\'a}ez: santiago.gomez-saez@iaas.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {The adoption of the workflow technology in the eScience domain has contributed
to the increase of simulation-based applications orchestrating different
services in a flexible and error-free manner. The nature of the provisioning
and execution of such simulations makes them potential candidates to be
migrated and executed in Cloud environments. The wide availability of
Infrastructure-as-a-Service (IaaS) Cloud offerings and service providers has
contributed to a raise in the number of supporters of partially or completely
migrating and running their scientific experiments in the Cloud. Focusing on
Scientific Workflow-based Simulation Environments (SWfSE) applications and
their corresponding underlying runtime support, in this research work we aim at
empirically analyzing and evaluating the impact of migrating such an
environment to multiple IaaS infrastructures. More specifically, we focus on
the investigation of multiple Cloud providers and their corresponding optimized
and non-optimized IaaS offerings with respect to their offered performance, and
its impact on the incurred monetary costs when migrating and executing a SWfSE.
The experiments show significant performance improvements and reduced monetary
costs when executing the simulation environment in off-premise Clouds.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INBOOK-2016-02&engl=0}
}