@inproceedings {INPROC-2014-61,
   author = {Marina Bitsaki and Christos Koutras and Georgios Koutras and Frank Leymann and Bernhard Mitschang and Christos Nikolaou and Nikos Siafakas and Steve Strauch and Nikos Tzanakis and Matthias Wieland},
   title = {{An Integrated mHealth Solution for Enhancing Patients' Health Online}},
   booktitle = {Proceedings of the 6th European Conference of the International Federation for Medical and Biological Engineering (MBEC'14)},
   publisher = {International Federation for Medical and Biological Engineering (IFMBE)},
   institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
   pages = {1--4},
   type = {Konferenz-Beitrag},
   month = {September},
   year = {2014},
   keywords = {Patient monitoring; COPD; ICT application services; Cloud technology; Online services; Mobile applications; Intelligent data mining},
   language = {Englisch},
   cr-category = {C.2.4 Distributed Systems,     H.2.8 Database Applications,     H.4.1 Office Automation,     J.3 Life and Medical Sciences},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/strauch''Steve Strauch/ a},
   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 = {Lack of time or economic difficulties prevent chronic obstructive pulmonary disease patients from communicating with their physicians, thus inducing exacerbation of their chronic condition and possible hospitalization. In this paper we propose a platform that integrates mobile application technologies and cloud computing to provide regular monitoring of patients and avoidance of medical emergencies.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-61&engl=0}
}
@inproceedings {INPROC-2014-27,
   author = {Santiago G{\'o}mez S{\'a}ez and Vasilios Andrikopoulos and Frank Leymann and Steve Strauch},
   title = {{Towards Dynamic Application Distribution Support for Performance Optimization in the Cloud}},
   booktitle = {Proceedings of the 7th IEEE International Conference on Cloud Computing (IEEE CLOUD 2014); Alaska, USA, June 27 - July 2, 2014},
   publisher = {IEEE Computer Society},
   institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
   pages = {248--255},
   type = {Konferenz-Beitrag},
   month = {Juni},
   year = {2014},
   keywords = {Synthetic Workload; Benchmark; Application Distribution; Application Deployment; Relational Database; TPC; Database-as-a-Service (DBaaS)},
   language = {Englisch},
   cr-category = {D.2.11 Software Engineering Software Architectures,     C.2.4 Distributed Systems,     D.2.8 Software Engineering Metrics},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-27/INPROC-2014-27.pdf},
   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 Cloud computing paradigm emerged by establishing new resources provisioning and consumption models. Together with the improvement of resource management techniques, these models have contributed to an increase in the number of application developers that are strong supporters of partially or completely migrating their application to a highly scalable and pay-per-use infrastructure. In this paper we derive a set of functional and non-functional requirements and propose a process-based approach to support the optimal distribution of an application in the Cloud in order to handle fluctuating over time workloads. Using the TPC-H workload as the basis, and by means of empirical workload analysis and characterization, we evaluate the application persistence layer's performance under different deployment scenarios using generated workloads with particular behavior characteristics.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-27&engl=0}
}
@inproceedings {INPROC-2014-06,
   author = {Steve Strauch and Vasilios Andrikopoulos and Santiago G{\'o}mez S{\'a}ez and Frank Leymann},
   title = {{Transparent Access to Relational Databases in the Cloud Using a Multi-Tenant ESB}},
   booktitle = {Proceedings of the 4th International Conference on Cloud Computing and Service Science (CLOSER'14)},
   publisher = {SciTePress},
   institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
   pages = {5--14},
   type = {Konferenz-Beitrag},
   month = {April},
   year = {2014},
   keywords = {Data Access Layer; Relational Databases; Enterprise Service Bus (ESB); Multi-Tenancy},
   language = {Englisch},
   cr-category = {C.2.4 Distributed Systems,     C.4 Performance of Systems,     D.2.11 Software Engineering Software Architectures,     H.2.0 Database Management General,     H.2.4 Database Management Systems},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/strauch''Steve Strauch/ a},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {In the last years Cloud computing has become popular among IT organizations aiming to reduce their operational costs. Applications can be designed to run in the Cloud, or can be partially or completely migrated to it. Migrating the data layer of an application to the Cloud, however, implies that existing applications might need to be adapted in order to access their migrated to the Cloud databases. In this work we examine how we can use an existing ESB to enable transparent access to the relational data store running either in the Cloud or on-premise. The goal of our approach is to minimize the effort required to adapt the application. In particular, we discuss the requirements and prototype realization of a Cloud aware data access layer for transparent data access, using an existing open source and multi-tenant aware ESB as the basis. We then evaluate the performance of our proposed solution by considering different Cloud providers and using example data from an existing benchmark as application workload.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-06&engl=0}
}
@inproceedings {INPROC-2014-02,
   author = {Santiago G{\'o}mez S{\'a}ez and Vasilios Andrikopoulos and Frank Leymann and Steve Strauch},
   title = {{Evaluating Caching Strategies for Cloud Data Access using an Enterprise Service Bus}},
   booktitle = {Proceedings of the IEEE International Conference on Cloud Engineering (IEEE IC2E 2014)},
   address = {Boston, Massachusetts, USA},
   publisher = {IEEE Computer Society},
   institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
   pages = {289--294},
   type = {Konferenz-Beitrag},
   month = {M{\"a}rz},
   year = {2014},
   keywords = {Multi-tenancy; Enterprise Service Bus (ESB); Cache; Relational Databases},
   language = {Englisch},
   cr-category = {C.2.4 Distributed Systems,     H.3.4 Information Storage and Retrieval Systems and Software},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-02/INPROC-2014-02.pdf},
   contact = {E-Mail: santiago.gomez-saez@iaas.uni-stuttgart.de},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {Nowadays different Cloud services enable enterprises to migrate applications to the Cloud. An application can be partially migrated by replacing some of its components with Cloud services, or by migrating one or multiple of its layers to the Cloud. As a result, accessing application data stored off-premise requires mechanisms to mitigate the negative impact on Quality of Service (QoS), e.g. due to network latency. In this work, we propose and realize an approach for transparently accessing data migrated to the Cloud using a multi-tenant open source Enterprise Service Bus (ESB) as the basis. Furthermore, we enhance the ESB with QoS awareness by integrating it with an open source caching solution. For evaluation purposes we generate a representative application workload using data from the TPC-H benchmark. Based on this workload, we then evaluate the optimal caching strategy among multiple eviction algorithms when accessing relational databases located at different Cloud providers.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-02&engl=0}
}
@inproceedings {INPROC-2014-01,
   author = {Johannes Wettinger and Vasilios Andrikopoulos and Steve Strauch and Frank Leymann},
   title = {{Characterizing and Evaluating Different Deployment Approaches for Cloud Applications}},
   booktitle = {Proceedings of the IEEE International Conference on Cloud Engineering (IEEE IC2E 2014); Boston, Massachusetts, USA, March 10 - 14, 2014.},
   publisher = {IEEE Computer Society},
   institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
   pages = {205--214},
   type = {Konferenz-Beitrag},
   month = {M{\"a}rz},
   year = {2014},
   language = {Englisch},
   cr-category = {D.2.11 Software Engineering Software Architectures,     K.6 Management of Computing and Information Systems},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {Fully automated provisioning and deployment in order to reduce the costs for managing applications is one of the most essential requirements to make use of the benefits of Cloud computing. Several approaches and tools are available to automate the involved processes. The DevOps community, for example, provides tooling and artifacts to realize deployment automation on Infrastructure as a Service level in a mostly application-oriented manner. Platform as a Service frameworks are also available for the same purpose. In this paper we categorize and characterize available deployment approaches independently from the underlying technology used. For this purpose, we choose Web applications with different technology stacks and analyze their specific deployment requirements. Afterwards, we provision these applications using each of the identified types of deployment approaches in the Cloud. Finally, we discuss the evaluation results and derive recommendations which deployment approach to use based on the deployment requirements of an application.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-01&engl=0}
}
@inproceedings {INPROC-2013-56,
   author = {Steve Strauch and Vasilios Andrikopoulos and Bachmann Thomas and Dimka Karastoyanova and Stephan Passow and Karolina Vukojevic-Haupt},
   title = {{Decision Support for the Migration of the Application Database Layer to the Cloud}},
   booktitle = {Proceedings of the 5th IEEE International Conference on Cloud Computing Technology and Science (CloudCom'13)},
   publisher = {IEEE Computer Society Press},
   institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
   pages = {639--646},
   type = {Konferenz-Beitrag},
   month = {Dezember},
   year = {2013},
   keywords = {Data Migration; Decision Support; Database layer; Application Refactoring},
   language = {Englisch},
   cr-category = {D.2.11 Software Engineering Software Architectures,     H.3.4 Information Storage and Retrieval Systems and Software},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/strauch''Steve Strauch/ a},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {Migrating an existing application to the Cloud is a complex and multi-dimensional problem requiring in many cases adapting the application in significant ways. Looking specifically into the database layer of the application, i.e. the aspect providing data persistence and manipulation capabilities, this involves dealing with differences in the granularity of interactions, refactoring of the application to cope with remote data sources, and addressing data confidentiality concerns. Toward this goal, in this work we present an application migration methodology which incorporates these aspects, and a decision support, application refactoring and data migration tool that assists application developers in realizing this methodology. For purposes of evaluating our proposal we present the results of a case study conducted in the context of an eScience project.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-56&engl=0}
}
@inproceedings {INPROC-2013-41,
   author = {Steve Strauch and Vasilios Andrikopoulos and Santiago G{\'o}mez S{\'a}ez and Frank Leymann},
   title = {{Implementation and Evaluation of a Multi-tenant Open-Source ESB}},
   booktitle = {Proceedings of the 2nd European Conference on Service-Oriented and Cloud Computing (ESOCC'13)},
   editor = {Lau Kung-Kiu and Lamersdorf Winfried and Pimentel Ernesto},
   publisher = {Springer Berlin Heidelberg},
   institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
   series = {Lecture Notes in Computer Science (LNCS)},
   volume = {8135},
   pages = {79--93},
   type = {Konferenz-Beitrag},
   month = {September},
   year = {2013},
   isbn = {978-3-642-40650-8},
   keywords = {Multi-tenancy; Enterprise Service Bus (ESB); ESB benchmarking; JBI specification; Platform as a Service},
   language = {Englisch},
   cr-category = {C.2.4 Distributed Systems},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/strauch''Steve Strauch/ a},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {Offering applications as a service in the Cloud builds on the notion of application multi-tenancy. Multi-tenancy, the sharing of application instances and their underlying resources between users from different organizational domains, allows service providers to maximize resource utilization and reduce servicing costs per user. Realizing application multi-tenancy however requires suitable enabling mechanisms offered by their supporting middleware. Furthermore, the middleware itself can be multi-tenant in a similar fashion. In this work we focus on enabling multi-tenancy for one of the most important components in service-oriented middleware, the Enterprise Service Bus (ESB). In particular, we discuss the prototype realization of a multi-tenant aware ESB, using an open source solution as the basis. We then evaluate the performance of our proposed solution by an ESB-specific benchmark that we extended for multi-tenancy purposes.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-41&engl=0}
}
@inproceedings {INPROC-2013-21,
   author = {Johannes Wettinger and Vasilios Andrikopoulos and Steve Strauch and Frank Leymann},
   title = {{Enabling Dynamic Deployment of Cloud Applications Using a Modular and Extensible PaaS Environment}},
   booktitle = {Proceedings of the IEEE 6th International Conference on Cloud Computing (IEEE CLOUD 2013); Santa Clara Marriott, CA, USA, June 27 - July 2, 2013},
   editor = {IEEE Computer Society},
   publisher = {Institute of Electrical and Electronics Engineers, Inc. (IEEE)},
   institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
   pages = {478--485},
   type = {Konferenz-Beitrag},
   month = {Juli},
   year = {2013},
   keywords = {Middleware Abstraction; Infrastructure Abstraction; Middleware-oriented Deployment; PaaS Model; Cloud Computing},
   language = {Englisch},
   cr-category = {D.2.11 Software Engineering Software Architectures,     K.6 Management of Computing and Information Systems},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2013-21/INPROC-2013-21.pdf},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {The Platform as a Service (PaaS) model promotes the development and deployment of applications on top of middleware solutions offered by the provider. Deploying an application in this model entails both the deployment of the application on top of the platform, but potentially also the deployment of the middleware components required by the application. Existing works enable the abstraction from the underlying infrastructure and allow for the creation of generic deployment plans for middleware components that automate the deployment of applications. In this paper we propose a middleware-oriented deployment approach that defines how the deployment of middleware components can be defined in a manner that allows to offer them as PaaS building blocks, and enable the automatic deployment of application components on them. We also present an evaluation of our proposal, together with the lessons learned during this activity.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-21&engl=0}
}
@inproceedings {INPROC-2013-18,
   author = {Vasilios Andrikopoulos and Steve Strauch and Frank Leymann},
   title = {{Decision Support for Application Migration to the Cloud: Challenges and Vision}},
   booktitle = {Proceedings of the 3rd International Conference on Cloud Computing and Service Science (CLOSER'13)},
   publisher = {SciTePress},
   institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
   pages = {1--7},
   type = {Konferenz-Beitrag},
   month = {Mai},
   year = {2013},
   keywords = {Application migration; decision support; Cloud-enabling applications},
   language = {Englisch},
   cr-category = {C.2.4 Distributed Systems,     D.2.11 Software Engineering Software Architectures},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/andrikopoulos''Vasilios Andrikopoulos/ a},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {The success of Cloud computing has encouraged many application developers to consider migrating their applications to the Cloud. Given the early market dominance of the IaaS service model, many existing works focus on selecting the best service provider for a set of criteria related to the virtualization and hosting of the application. In this work, we aim to progress the State of the Art by formulating a vision of a decision support system that incorporates multiple dimensions and different analysis tasks in feedback relationships with each other. The research challenges that need to be addressed towards this direction are identified and related to the different aspects of migration of applications to the various Cloud service models.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-18&engl=0}
}
@inproceedings {INPROC-2013-17,
   author = {Steve Strauch and Vasilios Andrikopoulos and Uwe Breitenb{\"u}cher and Santiago G{\'o}mez S{\'a}ez and Oliver Kopp and Frank Leymann},
   title = {{Using Patterns to Move the Application Data Layer to the Cloud}},
   booktitle = {Proceedings of the 5th International Conference on Pervasive Patterns and Applications (PATTERNS'13)},
   publisher = {Xpert Publishing Services},
   institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
   pages = {26--33},
   type = {Konferenz-Beitrag},
   month = {Mai},
   year = {2013},
   keywords = {Data layer; Cloud applications; Data migration; Cloud Data Patterns; Cloud data stores},
   language = {Englisch},
   cr-category = {C.2.4 Distributed Systems,     D.2.11 Software Engineering Software Architectures,     H.3.4 Information Storage and Retrieval Systems and Software},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/strauch''Steve Strauch/ a},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {Cloud services allow for hosting applications partially or completely in the Cloud by migrating their components and data. Especially with respect to data migration, a series of functional and non-functional challenges like data confidentiality arise when considering private and public Cloud data stores. In this paper we identify some of these challenges and propose a set of reusable solutions for them, organized together as a set of Cloud Data Patterns. Furthermore, we show how these patterns may impact the application architecture and demonstrate how they can be used in practice by means of a use case.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-17&engl=0}
}
@inproceedings {INPROC-2013-16,
   author = {Steve Strauch and Vasilios Andrikopoulos and Thomas Bachmann and Frank Leymann},
   title = {{Migrating Application Data to the Cloud Using Cloud Data Patterns}},
   booktitle = {Proceedings of the 3rd International Conference on Cloud Computing and Service Science (CLOSER'13)},
   publisher = {SciTePress},
   institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
   pages = {36--46},
   type = {Konferenz-Beitrag},
   month = {Mai},
   year = {2013},
   keywords = {application data migration; Cloud Data Patterns; Cloud Migration Scenarios; application refactoring},
   language = {Englisch},
   cr-category = {C.2.4 Distributed Systems,     D.2.11 Software Engineering Software Architectures,     H.3.4 Information Storage and Retrieval Systems and Software},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/strauch''Steve Strauch/ a},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {Taking advantage of the capabilities offered by Cloud computing requires either an application to be built specifically for it, or for existing applications to be migrated to it. In this work we focus on the latter case, and in particular on migrating the application data. Migrating data to the Cloud creates a series of technical, architectural and legal challenges that the State of the Art attempts to address. We organize such efforts into a set of migration scenarios and connect them with a list of reusable solutions for the application data migration in the form of patterns. From there we define an application data migration methodology and we demonstrate how it can be used in practice.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-16&engl=0}
}
@inproceedings {INPROC-2012-47,
   author = {Steve Strauch and Vasilios Andrikopoulos and Uwe Breitenb{\"u}cher and Oliver Kopp and Leymann Frank},
   title = {{Non-Functional Data Layer Patterns for Cloud Applications}},
   booktitle = {Proceedings of the 4th IEEE International Conference on Cloud Computing Technology and Science (CloudCom'12)},
   publisher = {IEEE Computer Society Press},
   institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
   pages = {601--605},
   type = {Konferenz-Beitrag},
   month = {Dezember},
   year = {2012},
   keywords = {data layer; cloud applications; data migration; cloud data patterns; cloud data stores},
   language = {Englisch},
   cr-category = {C.2.4 Distributed Systems,     D.2.11 Software Engineering Software Architectures,     H.3.4 Information Storage and Retrieval Systems and Software},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/strauch''Steve Strauch/ a},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {Cloud services allow for hosting applications partially or completely in the Cloud by migrating their components and data. Especially with respect to data migration, a series of functional and non-functional challenges like data confidentiality arise when considering private and public Cloud data stores. In this paper we identify some of these challenges and propose a set of reusable solutions focusing on the non-functional aspects, organized together as a set of Cloud Data Patterns.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-47&engl=0}
}
@inproceedings {INPROC-2012-46,
   author = {Steve Strauch and Vasilios Andrikopoulos and Frank Leymann and Dominik Muhler},
   title = {{ESB^MT: Enabling Multi-Tenancy in Enterprise Service Buses}},
   booktitle = {Proceedings of the 4th IEEE International Conference on Cloud Computing Technology and Science (CloudCom'12)},
   publisher = {IEEE Computer Society Press},
   institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
   pages = {456--463},
   type = {Konferenz-Beitrag},
   month = {Dezember},
   year = {2012},
   keywords = {multi-tenancy; enterprise service bus; cloud-enabled middleware},
   language = {Englisch},
   cr-category = {C.2.4 Distributed Systems},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/strauch''Steve Strauch/ a},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {Multi-tenancy is an essential property of Cloud computing. It helps service providers to maximize resource utilization and reduce servicing costs per customer. It is therefore important for key components of the contemporary enterprise environment like the Enterprise Service Bus (ESB) to support and enable multi-tenancy. For this purpose, in this work we investigate the requirements for multi-tenant ESB solutions, propose an implementation-agnostic ESB architecture that addresses these requirements, and discuss our proof-of-concept realization of this architecture.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-46&engl=0}
}
@inproceedings {INPROC-2012-45,
   author = {Steve Strauch and Vasilios Andrikopoulos and Santiago G{\'o}mez S{\'a}ez and Frank Leymann and Dominik Muhler},
   title = {{Enabling Tenant-Aware Administration and Management for JBI Environments}},
   booktitle = {Proceedings of the 5th International Conference on Service-Oriented Computing and Applications (SOCA'12)},
   publisher = {IEEE Computer Society Conference Publishing Services},
   institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
   pages = {206--213},
   type = {Konferenz-Beitrag},
   month = {Dezember},
   year = {2012},
   isbn = {978-1-4673-4775-4},
   keywords = {Multi-tenancy; Enterprise Service Bus (ESB); JBI specification; Platform as a Service},
   language = {Englisch},
   cr-category = {C.2.4 Distributed Systems,     C.4 Performance of Systems,     D.2.11 Software Engineering Software Architectures},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/strauch''Steve Strauch/ a},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {Enterprise Service Buses (ESBs) constitute a core middleware technology for each modern Service-Oriented Architecture (SOA) solution. Given the popularity of the Cloud paradigm, which is based on fundamental SOA concepts, it is only therefore natural to look into how ESBs can be transformed into native building blocks for Cloud platforms. As a first step of this effort, in this work we investigate how ESBs can become multi-tenant aware, i.e. able to support multiple tenants and their users sharing the same ESB instance. A generalized architecture based on the JBI specification implemented by a number of open source ESBs is presented for this purpose. We demonstrate the feasibility of our proposal by means of a proof of concept realization and we evaluate the performance of our solution against a non multi-tenant ESB that was used as the baseline for our implementation.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-45&engl=0}
}
@inproceedings {INPROC-2012-08,
   author = {Steve Strauch and Uwe Breitenb{\"u}cher and Oliver Kopp and Frank Leymann and Tobias Unger},
   title = {{Cloud Data Patterns for Confidentiality}},
   booktitle = {Proceedings of the 2nd International Conference on Cloud Computing and Service Science (CLOSER'12)},
   publisher = {SciTePress},
   institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
   pages = {387--394},
   type = {Konferenz-Beitrag},
   month = {April},
   year = {2012},
   keywords = {patterns; confidentiality; database layer; migration; distributed application architecture; cloud data store},
   language = {Englisch},
   cr-category = {C.2.4 Distributed Systems,     D.2.11 Software Engineering Software Architectures,     H.3.4 Information Storage and Retrieval Systems and Software},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/strauch''Steve Strauch/ a},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {Cloud computing enables cost-effective, self-service, and elastic hosting of applications in the Cloud. Applications may be partially or completely moved to the Cloud. When hosting or moving the database layer to the Cloud, challenges such as avoidance of disclosure of critical data have to be faced. The main challenges are handling different levels of confidentiality and satisfying security and privacy requirements. We provide reusable solutions in the form of patterns.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-08&engl=0}
}
@inproceedings {INPROC-2011-71,
   author = {Steve Strauch and Oliver Kopp and Frank Leymann and Tobias Unger},
   title = {{A Taxonomy for Cloud Data Hosting Solutions}},
   booktitle = {Proceedings of the International Conference on Cloud and Green Computing (CGC '11)},
   publisher = {IEEE Computer Society},
   institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
   pages = {577--584},
   type = {Konferenz-Beitrag},
   month = {Dezember},
   year = {2011},
   doi = {10.1109/DASC.2011.106},
   keywords = {cloud data hosting solution; taxonomy; distributed application architecture; database layer; cloud computing},
   language = {Englisch},
   cr-category = {C.2.4 Distributed Systems,     D.2.11 Software Engineering Software Architectures,     H.3.4 Information Storage and Retrieval Systems and Software},
   contact = {steve.strauch@iaas.uni-stuttgart.de},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {Cloud computing allows reducing capital expenditure by using resources on demand. We investigate how to build a database layer in the Cloud and present pure and hybrid Cloud data hosting solutions. The solutions are organized in a taxonomy. The properties used for organization are: application layer, deployment model, location, service model, data store type, and compatibility. Using the taxonomy, existing Cloud data hosting solutions are categorized.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-71&engl=0}
}
@inproceedings {INPROC-2010-92,
   author = {Aliaksandr Birukou and Vincenzo D'Andrea and Frank Leymann and Jacek Serafinski and Patr{\'\i}cia Silveira and Steve Strauch and Marek Tluczek},
   title = {{An Integrated Solution for Runtime Compliance Governance in SOA}},
   booktitle = {Proceedings of the 8th International Conference on Service-Oriented Computing (ICSOC'10), San Francisco, California, USA, December 7-10, 2010},
   publisher = {Springer},
   institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
   pages = {122--136},
   type = {Konferenz-Beitrag},
   month = {Dezember},
   year = {2010},
   doi = {10.1007/978-3-642-17358-5_9},
   keywords = {Compliance Governance, Business Process, Monitoring, SOA, Complex Event Processing},
   language = {Englisch},
   cr-category = {H.4.1 Office Automation},
   contact = {Please send an e-mail to steve.strauch@iaas.uni-stuttgart.de},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {In response to recent nancial scandals (e.g. those involving Enron, Fortis, Parmalat), new regulations for protecting the society from nancial and operational risks of the companies have been introduced. Therefore, companies are required to assure compliance of their operations with those new regulations as well as those already in place. Regulations are only one example of compliance sources modern organizations deal with every day. Other sources of compliance include licenses of business partners and other contracts, internal policies, and international standards. The diversity of compliance sources introduces the problem of compliance governance in an organization. In this paper, we propose an integrated solution for runtime compliance governance in Service-Oriented Architectures (SOAs). We show how the proposed solution supports the whole cycle of compliance management: from modeling compliance requirements in domain-speci c languages through monitoring them during process execution to displaying information about the current state of compliance in dashboards. We focus on the runtime part of the proposed solution and describe it in detail.We apply the developed framework in a real case study coming from EU FP7 project COMPAS, and this case study is used through the paper to illustrate our solution.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-92&engl=0}
}
@inproceedings {INPROC-2010-75,
   author = {David Schumm and Tobias Anstett and Frank Leymann and Daniel Schleicher and Steve Strauch},
   title = {{Essential Aspects of Compliance Management with Focus on Business Process Automation}},
   booktitle = {INFORMATIK 2010: Business Process and Service Science Proceedings of ISSS and BPSC},
   editor = {Witold Abramowicz and Rainer Alt and Klaus-Peter F{\"a}hnrich and Bogdan Franczyk and Leszek A. Maciaszek},
   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},
   volume = {177},
   pages = {127--138},
   type = {Konferenz-Beitrag},
   month = {September},
   year = {2010},
   language = {Englisch},
   cr-category = {H.4.1 Office Automation},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {Compliance requirements coming from laws, regulations and internal policies constrain how a company may carry out its business. A company must take various different actions for preventing compliance violations and for detecting them. Business processes have to be changed accordingly in order to adhere to these requirements. Manual controls need to be installed in order to affect the work which is done outside of IT systems. Technical controls are required for assuring compliance within IT systems. In this paper, we present a compliance management model that captures the compliance problem from a holistic point of view. We elaborate on a technical control which is called compliance fragment and we position it in the compliance management model. A compliance fragment is a connected, possibly incomplete process graph that can be used as a reusable building block for ensuring a consistent specification and integration of compliance into a workflow. In particular, we propose language extensions to BPEL for representing compliance fragments. Furthermore, we introduce a methodology for integrating compliance fragments into given workflows.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-75&engl=0}
}
@inproceedings {INPROC-2010-52,
   author = {David Schumm and Dimka Karastoyanova and Frank Leymann and Steve Strauch},
   title = {{Fragmento: Advanced Process Fragment Library}},
   booktitle = {Proceedings of the 19th International Conference on Information Systems Development (ISD'10), Prague, Czech Republic, August 25 - 27, 2010},
   publisher = {Springer},
   institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
   pages = {659--670},
   type = {Konferenz-Beitrag},
   month = {August},
   year = {2010},
   isbn = {978-1-4419-9645-9},
   keywords = {Process Fragment; Process Design; Reusability; Process Library},
   language = {Englisch},
   cr-category = {H.4.1 Office Automation,     D.3.3 Programming Language Constructs and Features},
   contact = {David.Schumm@iaas.uni-stuttgart.de},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {Reuse is a common discipline for decreasing software development time and for improving overall quality, independent from the domain. As business processes represent a fundamental asset of an organization, several concepts for enabling reuse during process modeling have been proposed. However, only few concrete examples for reusable process artifacts have been discussed so far. In this paper, we present the concept of process fragments and an example collection of process fragments for illustrating our reuse concept and for showing that it can ac-tually be applied in practice for an easier and faster development of process-based applications. The fragment examples demonstrate different characteristics such fragments may exhibit. We also argue that this work will encourage reuse of process logic in terms of fragments since it also provides an opportunity to design and develop a process fragment library for collecting process logic explicitly. As technical enabler for the approach we present a prototype called Fragmento.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-52&engl=0}
}
@inproceedings {INPROC-2010-03,
   author = {David Schumm and Frank Leymann and Zhilei Ma and Thorsten Scheibler and Steve Strauch},
   title = {{Integrating Compliance into Business Processes: Process Fragments as Reusable Compliance Controls}},
   booktitle = {Proceedings of the Multikonferenz Wirtschaftsinformatik (MKWI'10), G{\"o}ttingen, Germany, February 23-25, 2010},
   editor = {Schumann/Kolbe/Breitner/Frerichs},
   address = {G{\"o}ttingen},
   publisher = {Universit{\"a}tsverlag G{\"o}ttingen},
   institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
   pages = {2125--2137},
   type = {Konferenz-Beitrag},
   month = {Februar},
   year = {2010},
   isbn = {978-3-941875-31-9},
   keywords = {Business Process Compliance, Process Fragment, Reusability},
   language = {Englisch},
   cr-category = {H.4.1 Office Automation},
   contact = {David.Schumm@iaas.uni-stuttgart.de},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {Companies increasingly have to pay attention to compliance concerns addressing business processes. Flexibly reacting to changing requirements coming from laws, regulations, and internal guidelines, becomes a necessary part of business process management. In this paper we propose the application of the emerging concept of process fragments in the field of compliance management in process-based applications. We exemplify realizing compliance requirements employing the notion of process fragments, and we show its characteristics and its practical application using a scenario common in industry. In doing so, we discuss how a fragment can be identified, which design considerations need to be taken into account, we discuss efficient storage and retrieval, and which ways of integration into business processes are feasible. This approach leverages the reusability of both, process models and realizations of compliance requirements.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-03&engl=0}
}
@inproceedings {INPROC-2009-76,
   author = {Tobias Anstett and Dimka Karastoyanova and Frank Leymann and Ralph Mietzner and Ganna Monakova and Daniel Schleicher and Steve Strauch},
   title = {{MC-Cube: Mastering Customizable Compliance in the Cloud}},
   booktitle = {Proceedings of the 7th International Joint Conference on Service Oriented Computing, Stockholm, Sweden, November 23-27, 2009},
   editor = {Springer},
   publisher = {Springer Verlag},
   institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
   pages = {592--606},
   type = {Konferenz-Beitrag},
   month = {November},
   year = {2009},
   keywords = {Cloud Computing; IaaS; PaaS; SaaS; Monitoring; Enforcement},
   language = {Englisch},
   cr-category = {H.2.7 Database Administration},
   contact = {anstett@iaas.uni-stuttgart.de},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {Outsourcing parts of a company's processes becomes more and more important in a globalized, distributed economy. While archi- tectural styles and technologies such as service-oriented architecture and Web services facilitate the distribution of business process over several departments, enterprises and countries, these business processes still need to comply with various regulations. These regulations can be company regulations, national, or international regulations. When outsourcing IT-functions, enterprises must ensure that the overall regulations are met. Therefore they need evidence from their outsourcing partners that supports the proof of compliance to regulations. Furthermore it must be possible to enforce the adherence to compliance rules at partners. In this paper we introduce so-called compliance interfaces that can be used by customers to subscribe to evidence at a provider and to enforce regulations at a provider. We introduce a general compliance architecture that allows compliance to be monitored and enforced at services deployed in any emerging cloud delivery model.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-76&engl=0}
}
@inproceedings {INPROC-2009-41,
   author = {Tobias Anstett and Frank Leymann and Ralph Mietzner and Steve Strauch},
   title = {{Towards BPEL in the Cloud: Exploiting Different Delivery Models for the Execution of Business Processes}},
   booktitle = {Proceedings of the International Workshop on Cloud Services (IWCS 2009) in conjunction with the 7th IEEE International Conference on Web Services (ICWS 2009), Los Angeles, CA, USA, July 10, 2009},
   publisher = {IEEE},
   institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
   pages = {670--677},
   type = {Workshop-Beitrag},
   month = {Juli},
   year = {2009},
   keywords = {BPEL; Cloud Computing; SaaS; PaaS; IaaS; Security; Trust},
   language = {Englisch},
   cr-category = {H.4.1 Office Automation},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {More and more companies are outsourcing parts of their business processes to third party providers to exploit the expertise and economies of scale of these third party providers. In the IT field, emerging delivery models for software such as Software as a Service and cloud computing offer the possibility to outsource applications and computing infrastructure and thus enable enterprises to focus on their core competences. In this paper we investigate how the new delivery models affect the outsourcing of business processes modeled in WS-BPEL. WS-BPEL is the standard to model and execute business processes in Web service-based IT landscapes. We describe how security and trust issues affect the execution of BPEL processes in the cloud and show the requirements on the middleware supporting the execution of BPEL processes.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-41&engl=0}
}
@inproceedings {INPROC-2009-30,
   author = {Florian Daniel and Fabio Casati and Vincenzo D'Andrea and Steve Strauch and David Schumm and Frank Leymann and Emmanuel Mulo and Uwe Zdun and Schahram Dustdar and Samir Sebahi and Fabien de Marchi and Mohand-Said Hacid},
   title = {{Business Compliance Governance in Service-Oriented Architectures}},
   booktitle = {Proceedings of the IEEE Twenty-Third International Conference on Advanced Information Networking and Applications (AINA'09), Bradford, United Kingdom, May 26-29, 2009},
   editor = {Irfan Awan and Muhammad Younas and Takahiro Hara and Arjan Durresi},
   address = {Los Alamitos, California},
   publisher = {IEEE Press},
   institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
   pages = {113--120},
   type = {Konferenz-Beitrag},
   month = {Mai},
   year = {2009},
   isbn = {978-1-4244-4000-9},
   keywords = {Compliance, Process Fragments, SOA, Compliance governance, Business process management, View-based modeling},
   language = {Englisch},
   cr-category = {H.4.1 Office Automation},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {Governing business compliance with regulations, laws, best practices, contracts, and the like is not an easy task, and so far there are only limited software products available that help a company to express compliance rules and to analyze its compliance state. We argue that today’s SOA-based way of implementing and conducting business (e.g., using Web services and business process engines) lends itself very well to the development of a comprehensive compliance government solution that effectively aids companies in being compliant. In this paper, we contextualize the compliance problem in SOA-based businesses, we highlight which are the most salient research challenges that need to be addressed, and we describe our approach to compliance governance, spanning design, execution, and evaluation concerns.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-30&engl=0}
}
@inproceedings {INPROC-2009-23,
   author = {Branimir Wetzstein and Steve Strauch and Frank Leymann},
   title = {{Measuring Performance Metrics of WS-BPEL Service Compositions}},
   booktitle = {Proceedings of the Fifth International Conference on Networking and Services (ICNS 2009), Valencia, Spain, April 20-25, 2009},
   publisher = {IEEE Computer Society},
   institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
   type = {Konferenz-Beitrag},
   month = {April},
   year = {2009},
   keywords = {KPI, Performance Measurement, Process Performace Metric, WS-BPEL, Service Composition},
   language = {Englisch},
   cr-category = {H.4.1 Office Automation},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {In this paper we present an approach to the development of monitoring solutions for processes implemented as WSBPEL service compositions. The approach allows modeling of process performance metrics in a platform-independent manner and then generating an event-based monitor model for a specific WS-BPEL process engine. We create a metamodel which enables modeling of different types of process performance metrics. In particular, our approach supports modeling of metrics related to correlated processes. In the deployment phase, we generate a monitor model based on a proprietary event metamodel of a process engine. In addition, we determine which events are needed for the calculation of PPMs, and generate corresponding deployment information for the process engine.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-23&engl=0}
}
@article {ART-2013-10,
   author = {Steve Strauch and Vasilios Andrikopoulos and Santiago G{\'o}mez S{\'a}ez and Frank Leymann},
   title = {{ESB^MT: A Multi-tenant Aware Enterprise Service Bus}},
   journal = {International Journal of Next-Generation Computing},
   publisher = {Perpetual Innovation Media Pvt. Ltd.},
   volume = {4},
   number = {3},
   pages = {230--249},
   type = {Artikel in Zeitschrift},
   month = {November},
   year = {2013},
   issn = {0976-5034},
   keywords = {Enterprise Service Bus; Multi-tenancy; Cloud-enabled middleware},
   language = {Englisch},
   cr-category = {C.2.4 Distributed Systems},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/strauch''Steve Strauch/ a},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {Multi-tenancy, the sharing of the whole technological stack by different consumers at the same time, allows service providers to maximize resource utilization and reduce servicing costs per customer. Essential components of the contemporary enterprise environment like the Enterprise Service Bus (ESB) are therefore required to raise to the challenge of supporting and enabling multi-tenancy, becoming multi-tenant aware. Towards this goal, in this work we discuss the requirements for multi-tenant ESB solutions as fundamental building blocks in the Platform as a Service (PaaS) Cloud delivery model. Addressing these requirements, we propose a solution for dealing with multiple tenant contexts on the level of middleware, based on which we develop ESB^MT, an implementation agnostic multi-tenant aware ESB architecture that we instantiate based on the Apache ServiceMix ESB open source solution. Evaluating the performance of our proposal required the extension of an ESB benchmark, the results of which for different deployment options we also present in this work.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2013-10&engl=0}
}
@article {ART-2013-08,
   author = {Vasilios Andrikopoulos and Tobias Binz and Frank Leymann and Steve Strauch},
   title = {{How to adapt applications for the Cloud environment}},
   journal = {Computing},
   publisher = {Springer},
   volume = {95},
   number = {6},
   pages = {493--535},
   type = {Artikel in Zeitschrift},
   month = {Juni},
   year = {2013},
   doi = {10.1007/s00607-012-0248-2},
   keywords = {Cloud migration; application adaptation; Cloud-enabled applications; data layer;  business layer; migration types},
   language = {Englisch},
   cr-category = {D.2.0 Software Engineering General,     D.2.11 Software Engineering Software Architectures,     D.2.12 Software Engineering Interoperability,     H.2.m Database Management Miscellaneous},
   contact = {vasilios.andrikopoulos@iaas.uni-stuttgart.de},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {The migration of existing applications to the Cloud requires adapting them to a new computing paradigm. Existing works have focused on migrating the whole application stack by means of virtualization and deployment on the Cloud, delegating the required adaptation effort to the level of resource management. With the proliferation of Cloud services allowing for more flexibility and better control over the application migration, the migration of individual application layers, or even individual architectural components to the Cloud, becomes possible. Towards this goal, in this work we focus on the challenges and solutions for each layer when migrating different parts of the application to the Cloud. We categorize different migration types and identify the potential impact and adaptation needs for each of these types on the application layers based on an exhaustive survey of the State of the Art. We also investigate various cross-cutting concerns that need to be considered for the migration of the application, and position them with respect to the identified migration types. Finally, we present some of the open research issues in the field and position our future work targeting these research questions.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2013-08&engl=0}
}
@article {ART-2012-13,
   author = {Sergio Garc{\'\i}a-G{\'o}mez and Miguel Jim{\'e}nez-Ga{\~n}{\'a}n and Yehia Taher and Christof Momm and Frederic Junker and J{\'o}zsef B{\'\i}r{\'o} and Andreas Menychtas and Vasilios Andrikopoulos and Steve Strauch},
   title = {{Challenges for the Comprehensive Management of Cloud Services in a PaaS Framework}},
   journal = {Scalable Computing: Practice and Experience (SCPE)},
   publisher = {West University of Timisoara},
   volume = {13},
   number = {3},
   pages = {201--213},
   type = {Artikel in Zeitschrift},
   month = {November},
   year = {2012},
   issn = {1895-1767},
   keywords = {cloud; platform as a service; service composition},
   language = {Englisch},
   cr-category = {C.2.4 Distributed Systems,     D.2.11 Software Engineering Software Architectures},
   ee = {http://www.scpe.org/index.php/scpe/article/view/793/0},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/strauch''Steve Strauch/ a},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {Cloud services allow for hosting applications partially or completely in the Cloud by migrating their components and data. Especially with respect to data migration, a series of functional and non-functional challenges like data confidentiality arise when considering private and public Cloud data stores. In this paper we identify some of these challenges and propose a set of reusable solutions focusing on the non-functional aspects, organized together as a set of Cloud Data Patterns.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2012-13&engl=0}
}
@article {ART-2011-18,
   author = {Oliver Kopp and Katharina G{\"o}rlach and Dimka Karastoyanova and Frank Leymann and Michael Reiter and David Schumm and Mirko Sonntag and Steve Strauch and Tobias Unger and Matthias Wieland and Rania Khalaf},
   title = {{A Classification of BPEL Extensions}},
   journal = {Journal of Systems Integration},
   publisher = {Online},
   volume = {2},
   number = {4},
   pages = {2--28},
   type = {Artikel in Zeitschrift},
   month = {November},
   year = {2011},
   issn = {1804-2724},
   keywords = {BPEL Extension; Classification of Extensions; Extension Guidelines},
   language = {Englisch},
   cr-category = {H.4.1 Office Automation},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2011-18/ART-2011-18.pdf,     http://www.si-journal.org/index.php/JSI/article/view/103},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {The Business Process Execution Language (BPEL) has emerged as de-facto standard for business processes implementation. This language is designed to be extensible for including additional valuable features in a standardized manner. There are a number of BPEL extensions available. They are, however, neither classified nor evaluated with respect to their compliance to the BPEL standard. This article fills this gap by providing a framework for classifying BPEL extensions, a classification of existing extensions, and a guideline for designing BPEL extensions.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2011-18&engl=0}
}
@article {ART-2011-02,
   author = {David Schumm and Dimka Karastoyanova and Oliver Kopp and Frank Leymann and Mirko Sonntag and Steve Strauch},
   title = {{Process Fragment Libraries for Easier and Faster Development of Process-based Applications}},
   journal = {Journal of Systems Integration},
   publisher = {Online},
   volume = {2},
   number = {1},
   pages = {39--55},
   type = {Artikel in Zeitschrift},
   month = {Januar},
   year = {2011},
   issn = {1804-2724},
   keywords = {Process Fragment; Process Design; Reusability; Process Library.},
   language = {Englisch},
   cr-category = {H.4.1 Office Automation},
   ee = {http://www.si-journal.org/,     http://www.si-journal.org/index.php/JSI/article/view/83},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {The term “process fragment” is recently gaining momentum in business process management research. We understand a process fragment as a connected and reusable process structure, which has relaxed completeness and consistency criteria compared to executable processes. We claim that process fragments allow for an easier and faster development of process-based applications. As evidence to this claim we present a process fragment concept and show a sample collection of concrete, real-world process fragments. We present advanced application scenarios for using such fragments in development of process-based applications. Process fragments are typically managed in a repository, forming a process fragment library. On top of a process fragment library from previous work, we discuss the potential impact of using process fragment libraries in cross-enterprise collaboration and application integration.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2011-02&engl=0}
}
@inbook {INBOOK-2014-02,
   author = {Steve Strauch and Vasilios Andrikopoulos and Dimka Karastoyanova and Karolina Vukojevic},
   title = {{Migrating eScience Applications to the Cloud: Methodology and Evaluation}},
   series = {Cloud Computing with E-science Applications},
   publisher = {CRC Press/Taylor \& Francis},
   type = {Beitrag in Buch},
   month = {Dezember},
   year = {2014},
   keywords = {Data Migration; Decision Support; Database layer; Application Refactoring},
   language = {Englisch},
   cr-category = {D.2.11 Software Engineering Software Architectures,     H.3.4 Information Storage and Retrieval Systems and Software},
   contact = {steve.strauch@iaas.uni-stuttgart.de},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {eScience is an active field of research striving to enable faster scientific discovery and ground-breaking research in different scientific domains by means of information technology. In recent years Cloud computing has gained significant acceptance in both the enterprise application management and scientific computing for its promise to reduce infrastructure costs and provide virtually unlimited computational power and data storage - requirements of particular importance for businesses, and of even greater importance to scientists and research organizations. While research in this field is very active in providing novel concepts, techniques and principles towards building Cloud-native applications, there is a significant effort to Cloud-enable existing applications in order to reuse existing systems and therefore investments. Typically, Cloud-enabling applications is related to the migration of whole systems or parts of them on a public or private Cloud environment. In this work we present a vendor- and technology-independent methodology for migrating the database layer of applications, and refactoring the application architecture. The methodology is applicable to applications in different application domains and is agnostic to the types of data sources. It fulfils requirements also presented in this work, which we have identified in collaboration with software engineers and domain experts in several research projects. We use this methodology to migrate the database layer of a scientific workflow management system (SimTech SWfMS), which we developed in the scope of our research activities in the SimTech project. The migration of the SimTech SWfMS has been done using the Cloud Data Migration Support Tool - a proof of concept implementation of the methodology. Both the introduced methodology and the supporting tool have been evaluated and our findings are presented.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INBOOK-2014-02&engl=0}
}
@inbook {INBOOK-2013-03,
   author = {Vasilios Andrikopoulos and Steve Strauch and Christoph Fehling and Frank Leymann},
   title = {{CAP-Oriented Design for Cloud-Native Applications}},
   series = {Cloud Computing and Services Science},
   publisher = {Springer International Publishing},
   series = {Communications in Computer and Information Science},
   volume = {367},
   pages = {215--229},
   type = {Beitrag in Buch},
   month = {Dezember},
   year = {2013},
   doi = {10.1007/978-3-319-04519-1_14},
   keywords = {CAP Theorem; Cloud Patterns; Cloud-native Applications Design},
   language = {Englisch},
   cr-category = {C.2.4 Distributed Systems,     D.2.11 Software Engineering Software Architectures,     H.3.4 Information Storage and Retrieval Systems and Software},
   ee = {http://link.springer.com/chapter/10.1007/978-3-319-04519-1_14},
   contact = {vasilios.andrikopoulos@iaas.uni-stuttgart.de},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
   abstract = {Brewer's conjecture, and its resulting formalization as the CAP theorem, impose serious limitations on the consistency, availability and network partitioning tolerance characteristics of distributed systems. Despite its importance however, few works explicitly consider the implications of the CAP theorem in the design of applications, especially for applications that are designed natively for the Cloud. In order to address this need, in this work we propose a CAP-oriented design methodology for Cloud-native applications. For this purpose we build and extend our previous work on Cloud architectural patterns. Finally, we show how the methodology can be used in practice to design an application solution with desired CAP properties.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INBOOK-2013-03&engl=0}
}