@demo {2025:apiace:vissoft,
	title = {EVOSCAT: Exploring Software Change Dynamics in Large-Scale Historical Datasets},
	year = {2025},
	month = {September},
	publisher = {IEEE},
	address = {Auckland, New Zealand},
	abstract = {Long lived software projects encompass a large number of artifacts, which undergo many revisions throughout their history. Empirical software engineering researchers studying software evolution gather and collect datasets with millions of events, representing changes introduced to specific artifacts. In this paper, we propose EVOSCAT, a tool that attempts addressing temporal scalability through the usage of interactive density scatterplot to provide a global overview of large historical datasets mined from open source repositories in a single visualization.  EVOSCAT intends to provide researchers with a mean to produce scalable visualizations that can help them explore and characterize evolutions datasets, as well as comparing the histories of individual artifacts, both in terms of 1) observing how rapidly different artifacts age over multiple-year-long time spans 2) how often metrics associated with each artifacts tend towards an improvement or worsening. The paper shows how the tool can be tailored to specific analysis needs (pace of change comparison, clone detection, freshness assessment) thanks to its support for flexible configuration of history scaling and alignment along the time axis, artifacts sorting and interactive color mapping, enabling the analysis of millions of events obtained by mining the histories of tens of thousands of software artifacts. We include in this paper a gallery showcasing datasets gathering specific artifacts (OpenAPI descriptions, GitHub workflow definitions) across multiple repositories, as well as diving into the history of specific popular open source projects.},
	keywords = {Interactive Scatterplot, Large-Scale Historical Data, Software Evolution Visualization},
	doi = {10.1109/VISSOFT67405.2025.00021},
	url = {https://arxiv.org/abs/2508.10852},
	author = {Souhaila Serbout and Diana Carolina Mu{\~n}oz Hurtado and Hassan Atwi and Edoardo Riggio and Cesare Pautasso}
}
@conference {apiace:2025:icsa,
	title = {Mining Security Documentation Practices in OpenAPI Descriptions},
	booktitle = {22nd IEEE International Conference on Software Architecture (ICSA)},
	year = {2025},
	month = {March},
	address = {Odense, Denmark},
	abstract = {Security is an integral requirement of any trustworthy software architecture, particularly critical for application programming interfaces (APIs). In this paper, we survey security documentation practices, specifically API security schemes related to authentication and authorization, by mining a large collection of OpenAPI descriptions retrieved from open-source GitHub repositories. Our study focuses on detecting existing security schemes and evaluating their prevalence and positioning within API descriptions. We distinguish whether security schemes are introduced locally (at the path or operation level) or globally (for the entire API). Our analysis highlights scenarios where security schemes are featured in APIs in different proportions over time, thus tracking whether the API documentation tends to include more (or less) security details as the API evolves.},
	keywords = {API Analytics, OpenAPI, Security},
	author = {Diana Carolina Mu{\~n}oz Hurtado and Souhaila Serbout and Cesare Pautasso}
}
@conference {apiace:2023:vissoft,
	title = {Interactively exploring API changes and versioning consistency},
	booktitle = {11th IEEE Working Conference on Software Visualization (VISSOFT 2023)},
	year = {2023},
	month = {October},
	pages = {28-39},
	publisher = {IEEE},
	organization = {IEEE},
	address = {Bogota, Colombia},
	abstract = {Application Programming Interfaces (APIs) evolve
over time. As they change, they are expected to be versioned
based on how changes might affect their clients. In this paper, we
present two novel visualizations specifically designed to represent
all structural changes and the level of adherence to semantic
versioning practices over time. They can also serve for characterizing and comparing the evolution history of different Web
APIs. The API VERSION CLOCK helps to visualize the sequence
of API changes over time and highlight inconsistencies between
major, minor, or patch version changes and the corresponding
introduced breaking or non-breaking changes applied to the
API. The API CHANGES overview aggregates all changes to
an OpenAPI (OAS) description, highlighting the unstable vs.
the stable elements of the API over its entire history. Both
visualizations can be automatically created using the APICTURE,
a command-line and web-based tool that analyzes the histories
of git code repositories containing OAS descriptions, extracting
the necessary data for generating visualizations and computing
metrics related to API evolution and versioning. The visualizations have been successfully applied to classify, compare, and
interactively explore the multi-year evolution history of APIs with
up to hundreds of individual commits.},
	keywords = {API Versioning; Software Visualization, visualization},
	doi = {10.1109/VISSOFT60811.2023.00013},
	url = {https://ieeexplore.ieee.org/document/10350155},
	author = {Souhaila Serbout and Diana Carolina Mu{\~n}oz Hurtado and Cesare Pautasso}
}
@conference {2018:asq:disa,
	title = {Short Texts Analysis for Teacher Assistance during Live Interactive Classroom Presentations},
	booktitle = {World Symposium on Digital Intelligence for Systems and Machines (DISA2018)},
	year = {2018},
	month = {August},
	publisher = {IEEE},
	organization = {IEEE},
	address = {Ko{\v s}ice, Slovakia},
	abstract = {We aim to improve the communication process of a teacher with students during lectures using question answering. Our work is focused on the analysis of students{\textquoteright} answers to support the teacher in his or her lecturing. We work with students{\textquoteright} answers to open questions, where it is impossible to identify finite number of solutions. In large classes it is impossible to react in real time to such answers since their evaluation is time consuming. We propose our own approach that helps the teacher by grouping similar answers. These groups are created based on proposed method employing text classification and clustering. Proposed method automatically estimates a number of clusters in answers using combination of k-Nearest Neighbors (KNN) algorithm and affinity propagation. We evaluated the method on real data in Slovak language collected from the course Principles of Software Engineering using real time presentation system ASQ.},
	keywords = {ASQ, clustering},
	author = {Michal Hucko and Peter Gaspar and Matus Pikuliak and Vasileios Triglianos and Cesare Pautasso and Maria Bielikova}
}
@inproceedings {2017:asq:pale,
	title = {Experiences Using an Interactive Presentation Platform in a Functional and Logic Programming Course.},
	year = {2017},
	month = {July},
	publisher = {ACM},
	address = {Bratislava, Slovakia},
	abstract = {Modern constructivist approaches to education dictate active experimentation with the study material and have been linked with improved learning outcomes in STEM fields. During classroom time we believe it is important for students to experiment with the lecture material since active recall helps them to start the memory encoding process as well as to catch misconceptions early and to prevent them from taking root. In this paper, we report on our experiences using ASQ, a Web-based interactive presentation tool in a functional and logic programming course taught at the Faculty of Informatics and Information Technologies at the Slovak University of Technology in Bratislava. ASQ allowed us to collect immediate feedback from students and retain their attention by asking complex types of questions and aggregating student answers in real time. From our experience we identified several requirements and guidelines for successfully adopting ASQ. One of the most critical concerns was how to estimate the time when to stop collecting the students{\textquoteright} answers and proceed to their evaluation and discussion with the class. We also report the students{\textquoteright} feedback on the ASQ system that we collected in the form of the standard SUS questionnaire. 
},
	keywords = {ASQ},
	author = {Vasileios Triglianos and Martin Labaj and Robert Moro and Jakub Simko and Michal Hucko and Jozef Tvarozek and Cesare Pautasso and Maria Bielikova}
}
@inproceedings {2017:benchflow:wesoa,
	title = {Lessons Learned from Evaluating Workflow Management Systems},
	year = {2017},
	month = {November},
	publisher = {Springer},
	address = {Malaga, Spain},
	abstract = {Workflow Management Systems (WfMSs) today act as service composition engines and service-oriented middleware to enable the execution of automated business processes. 
Automation based on WfMSs promises to enable the model-driven construction of flexible and easily maintainable services with high-performance characteristics. 
In the past decade, significant effort has been invested into standardizing WfMSs that compose services, with standards such as the Web Services Business Process Execution Language (WS-BPEL) or the Business Process Model and Notation (BPMN).
One of the aims of standardization is to enable users of WfMSs to compare different systems and to avoid vendor lock-in. 
Despite these efforts, there are many expectations concerning portability, performance efficiency, usability, reliability and maintainability of WfMSs that are likely to be unfulfilled.
In this work, we synthesize the findings of two research initiatives that deal with WfMSs conformance and performance benchmarking to distill a set of lessons learned and best practices. 
These findings provide useful advice for practitioners who plan to evaluate and use WfMSs and for WfMS vendors that would like to foster wider adoption of process-centric service composition middleware. },
	keywords = {BenchFlow, Lessons Learned, Workflow Management Systems},
	author = {J{\"o}rg Lenhard and Vincenzo Ferme and Simon Harrer and Matthias Geiger and Cesare Pautasso}
}
@conference {asq:2017:umap,
	title = {Measuring student behaviour dynamics in a large interactive classroom setting},
	booktitle = {25th International Conference on User Modelling, Adaption and Personalisation (UMAP 2017)},
	year = {2017},
	month = {July},
	pages = {212--220},
	publisher = {ACM},
	organization = {ACM},
	address = {Bratislava, Slovakia},
	abstract = {Digital devices (most often laptops and smartphones), though desired tools by students in a higher education classroom, have in the past been shown to serve more as distractors than supporters of learning. One of the reasons is the often undirected nature of the devices{\textquoteright} usage. With our work we aim to turn students{\textquoteright} digital devices into teaching and communication tools by seamlessly interleaving lecture material and complex questions in the students{\textquoteright} browser through ASQ, a Web application for broadcasting and tracking interactive presentations. ASQ{\textquoteright}s fine-grained logging abilities allow us to track second by second to what extent students are engaging with ASQ which in turn enables insights into student behaviour dynamics. This setup enables us to conduct {\textquoteleft}{\textquoteleft}in situ{\textquoteright}{\textquoteright} experiments. Based on the logs collected in a longitudinal study over a ten week period across 14 lectures with more than 300 students, we investigate (i) to what extent ASQ can be reliably employed to assess attention and learning in the classroom, and (ii) whether different in-class question spacing strategies impact student learning and engagement.},
	keywords = {ASQ},
	doi = {10.1145/3079628.3079671},
	url = {http://dl.acm.org/authorize?N31530},
	author = {Vasileios Triglianos and Sambit Praharaj and Cesare Pautasso and Alessandro Bozzon and Claudia Hauff}
}
@conference {2017:europlop,
	title = {A Pattern Language for Workflow Engine Conformance and Performance Benchmarking},
	booktitle = {22nd European Conference on Pattern Languages of Programs (EuroPLoP)},
	year = {2017},
	month = {July},
	publisher = {ACM},
	organization = {ACM},
	address = {Kloster Irsee, Germany},
	abstract = {Workflow engines are frequently used in the domains of business process management, service orchestration, and cloud computing, where they serve as middleware platforms for integrated business applications. Engines have a significant impact on the quality of service provided by hosted applications. Therefore, it is desirable to compare them and to select the most appropriate engine for a given task. To enable such a comparison, approaches for benchmarking workflow engines have emerged. Although these approaches deal with different quality attributes, i.e., performance or standard conformance, they face many reoccurring design and implementation problems, which have been solved in similar ways. In this paper, we present a pattern language that captures such common solutions to reoccurring problems (e.g., from test identification, benchmarking procedure validation, automatic engine interaction, and workflow execution observation) in the area of workflow engine conformance and performance benchmarking. Our aim is to help future benchmark authors with the pattern language presented in this paper to benefit from our experience with the design and implementation of workflow engine benchmarks and benchmarking tools},
	keywords = {BenchFlow, pattern language},
	doi = {10.1145/3147704.3147705},
	author = {Simon Harrer and J{\"o}rg Lenhard and Oliver Kopp and Vincenzo Ferme and Cesare Pautasso}
}
@article {benchflow:2017:icse,
	title = {Workflow Management Systems Benchmarking: Unfulfilled Expectations and Lessons Learned},
	year = {2017},
	month = {May},
	address = {Buenos Aires, Argentina},
	abstract = {Workflow Management Systems (WfMSs) are a type of middleware that enables the execution of automated business processes. Users rely on WfMSs to construct flexible and easily maintainable software systems. Significant effort has been invested into standardising languages for business processes execution, with standards such as the Web Services Business Process Execution Language 2.0 or the Business Process Model and Notation 2.0.
Standardisation aims at avoiding vendor lock-in and enabling WfMS users to compare different systems. The reality is that, despite standardisation efforts, different independent research initiatives show that objectively comparing WfMSs is still challenging. As a result, WfMS users are likely to discover unfulfilled expectations while evaluating and using these systems. In this work, we discuss the findings of two research initiatives dealing with WfMSs benchmarking, presenting unfulfilled expectations and lessons learned concerning WfMSs{\textquoteright} usability, reliability, and portability.  Our goal is to provide advice for practitioners implementing or planning to use WfMSs.},
	keywords = {Lessons Learned, Workflow Management Systems},
	doi = {10.1109/ICSE-C.2017.126},
	author = {Vincenzo Ferme and J{\"o}rg Lenhard and Simon Harrer and Matthias Geiger and Cesare Pautasso}
}
@article {swinsight:2016:janfeb,
	title = {A Decade of  Enterprise  Integration Patterns: A Conversation with the Authors},
	journal = {IEEE Software},
	volume = {1},
	year = {2016},
	month = {January-February},
	pages = {13-19},
	abstract = {Department editors Olaf Zimmerman and Cesare Pautasso interview Gregor Hohpe and Bobby Woolf, authors of Enterprise Integration Patterns. They discuss the book{\textquoteright}s impact, pattern language design, message-oriented middleware, integration technology{\textquoteright}s evolution, and the authors{\textquoteright} future plans. },
	keywords = {Enterprise Integration Patterns},
	doi = {http://doi.ieeecomputersociety.org/10.1109/MS.2016.11},
	url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7368007},
	author = {Olaf Zimmermann and Cesare Pautasso and Gregor Hohpe and Bobby Woolf}
}
@conference {asq:2016:ectel,
	title = {Inferring student attention with ASQ},
	booktitle = {11th European Conference on Technology Enhanced Learning (EC-TEL)},
	year = {2016},
	month = {September},
	publisher = {Springer},
	organization = {Springer},
	address = {Lyon, France},
	abstract = {ASQ is a Web application for broadcasting and tracking interactive presentations, which can be used to support active learning pedagogies during lectures, labs and exercise sessions. Students connect their smartphones, tablets or laptops to receive the current slide as it is being explained by the teacher. Slides can include interactive teaching elements (usually questions of different forms). In contrast to other existing platforms, ASQ does not only collect, aggregate and visualize the answers in real-time, it also supports the data analytics in the classroom paradigm by providing the teacher with a real-time analysis of student behaviour during the entire session. One vital aspect of student behaviour is (in)attention and in this paper we discuss how we infer --- in real-time --- student attention based on log traces ASQ collects.},
	keywords = {analytics, ASQ},
	author = {Vasileios Triglianos and Cesare Pautasso and Alessandro Bozzon and Claudia Hauff}
}
@conference {rest:2015:wicsa,
	title = {A conversation based approach for modeling REST APIs},
	booktitle = {12th Working IEEE / IFIP Conference on Software Architecture (WICSA 2015)},
	year = {2015},
	month = {May},
	address = {Montreal, Canada},
	abstract = {Conversations are a well-known concept in service design to describe complex interactions between a client and one or multiple services. The REST architectural style constrains the characteristics of clients, servers and their interactions in REST architectures which consequently has an impact on conversations in such systems. The relation between conversations and REST architectures and how such RESTful conversations can be characterized has not been studied in detail yet. In this paper we discuss the characteristics of conversations in REST architectures and introduce an initial set of commonly used conversation types. Based on this, we propose to use conversations as a modeling tool for the design of REST APIs at a higher level of abstraction. We also introduce a corresponding interaction centric metamodel for REST APIs. The characterization of RESTful conversations enables a new interaction centric viewpoint on REST architectures which can be also applied for modeling REST APIs on an abstraction level that enables users to focus on the essential functionality of their REST API.},
	keywords = {conversation, model-driven engineering, REST, RESTful conversation},
	url = {http://wicsa2015.org/wicsa-sessions.html$\#$WS5},
	author = {Florian Haupt and Frank Leymann and Cesare Pautasso}
}
@conference {jopera:2008:icac,
	title = {Automatic Configuration of an Autonomic Controller: An Experimental Study with Zero-Configuration Policies},
	booktitle = {5th International Conference on Autonomic Computing (ICAC 2008)},
	year = {2008},
	month = {June},
	pages = {67-76},
	publisher = {IEEE},
	organization = {IEEE},
	address = {Chicago, IL, USA},
	abstract = {Autonomic control managers can remove the need for manual system configuration in order to achieve good performance and efficient resource utilization. However, simple controllers based on reconfiguration actions tied to thresholds, or {\textquoteright}if-then{\textquoteright} rules, themselves need to be configured and tuned in order to adapt the controller behavior to the expected workload characteristic. In this paper we present an experimental study of zero-configuration policies that can be automatically tuned based on analytical models of the system under control. In particular, we have designed and implemented a threshold-free self-configuration policy for a distributed workflow execution engine and compared it with a standard PID controller. The experimental results included in the paper show that using such a policy the controller can tune itself in addition to reconfiguring the distributed engine and the proposed policy out-performs simpler policies that require manual and error-prone tuning of their parameters.},
	keywords = {analytical models, automatic configuration, automatic control, autonomic controller, control system synthesis, distributed workflow execution engine, PID control, resource management, resource utilization, workload characteristic, zero-configuration policies},
	doi = {10.1109/ICAC.2008.29},
	author = {Thomas Heinis and Cesare Pautasso}
}
@conference {ccgrid2008,
	title = {Initializing a National Grid Infrastructure Lessons Learned from the Swiss National Grid Association Seed Project},
	booktitle = {8th IEEE International Symposium on Cluster Computing and the Grid (CCGRID 2008)},
	year = {2008},
	month = {May},
	pages = {169-176},
	publisher = {IEEE},
	organization = {IEEE},
	address = {Lyon, France},
	abstract = {In addition to multi-national Grid infrastructures, several countries operate their own national Grid infrastructures to support science and industry within national borders. These infrastructures have the benefit of better satisfying the needs of local, regional and national user communities. Although Switzerland has strong research groups in several fields of distributed computing, only recently a national Grid effort was kick-started to integrate a truly heterogeneous set of resource providers, middleware pools, and users. In the following article we discuss our efforts to start Grid activities at a national scale to combine several scientific communities and geographical domains. We make a strong case for the need of standards that have to be built on top of existing software systems in order to provide support for a heterogeneous Grid infrastructure.},
	keywords = {distributed computing, grid computing, middleware, national grid infrastructure},
	doi = {10.1109/CCGRID.2008.62},
	author = {Nabil Abdennadher and Peter Engel and Derek Feichtinger and Dean Flanders and Placi Flury and Sigve Haug and Pascal Jermini and Sergio Maffioletti and Cesare Pautasso and Heinz Stockinger and Wibke Sudholt and Michela Thi{\'e}mard and Nadya Williams and Christoph Witzig}
}
@article {DBLP:journals/bioinformatics/QuandtHMHMPAL08,
	title = {swissPIT: a novel approach for pipelined analysis of mass spectrometry data},
	journal = {Bioinformatics},
	volume = {24},
	number = {11},
	year = {2008},
	pages = {1416-1417},
	abstract = {The identification and characterization of peptides from tandem mass spectrometry (MS/MS) data represents a critical aspect of proteomics. Today, tandem MS analysis is often performed by only using a single identification program achieving identification rates between 10-50\% (Elias and Gygi, 2007). Beside the development of new analysis tools, recent publications describe also the pipelining of different search programs to increase the identification rate (Hartler et al., 2007; Keller et al., 2005). The Swiss Protein Identification Toolbox (swissPIT) follows this approach, but goes a step further by providing the user an expandable multi-tool platform capable of executing workflows to analyze tandem MS-based data. One of the major problems in proteomics is the absent of standardized workflows to analyze the produced data. This includes the pre-processing part as well as the final identification of peptides and proteins. The main idea of swissPIT is not only the usage of different identification tool in parallel, but also the meaningful concatenation of different identification strategies at the same time. The swissPIT is open source software but we also provide a user-friendly web platform, which demonstrates the capabilities of our software and which is available at http://swisspit.cscs.ch upon request for account.},
	keywords = {bioinformatics, scientific workflow management},
	doi = {10.1093/bioinformatics/btn139},
	url = {http://www.ncbi.nlm.nih.gov/pubmed/18436540},
	author = {Andreas Quandt and Patricia Hernandez and Alexandre Masselot and C{\'e}line Hernandez and Sergio Maffioletti and Cesare Pautasso and Ron D. Appel and Fr{\'e}d{\'e}rique Lisacek}
}
@article {jopjauto07,
	title = {Autonomic resource provisioning for software business processes},
	journal = {Information and Software Technology},
	volume = {49},
	year = {2007},
	month = {January},
	pages = {65-80},
	abstract = {Software development nowadays involves several levels of abstraction: starting from the programming of single objects, to their combination into components, to their publication as services and the overall architecture linking elements at each level. As a result, software engineering is dealing with a wider range of artifacts and concepts (i.e., in the context of this paper: services and business processes) than ever before. In this paper we explore the importance of having an adequate engine for executing business processes written as compositions of Web services. The paper shows that, independently of the composition language used, the overall scalability of the system is determined by how the run-time engine treats the process execution. This is particularly relevant at the service level because publishing a process through a Web service interface makes it accessible to an unpredictable and potentially very large number of clients. As a consequence, the process developer is confronted with the difficult question of resource provisioning. Determining the optimal configuration of the distributed engine that runs the process becomes sensitive both to the actual number of clients and to the kinds of processes to be executed. The main contribution of the paper is to show how resource provisioning for software business processes can be solved using autonomic computing techniques. The engine separates execution in two stages (navigation and dispatching) and uses a controller to allocate the node of a cluster of computers to each one of those stages as the workload changes. The controller can be configured with different policies that define how to reconfigure the system. To prove the feasibility of the concept, we have implemented the autonomic controller and evaluated its performance with an extensive set of experiments.},
	keywords = {autonomic computing, distributed business process execution engines, service oriented architectures, Web service composition},
	doi = {10.1016/j.infsof.2006.08.010},
	author = {Cesare Pautasso and Thomas Heinis and Gustavo Alonso}
}
@conference {jophealthgrid07,
	title = {Grid-based Analysis of Tandem Mass Spectrometry Data in Clinical Proteomics},
	booktitle = {Health Grid 2007},
	year = {2007},
	address = {Geneva, Switzerland},
	abstract = {Biomarker detection is one of the greatest challenges in Clinical Proteomics. Today, great hopes are placed into tandem mass spectrometry (MS/MS) to discover potential biomarkers. MS/MS is a technique that allows large scale data analysis, including the identification, characterization, and quantification of molecules. Especially the identification process, that implies to compare experimental spectra with theoretical amino acid sequences stored in specialized databases, has been subject for extensive research in bioinformatics since many years. Dozens of identification programs have been developed addressing different aspects of the identification process but in general, clinicians are only using a single tools for their data analysis along with a single set of specific parameters. Hence, a significant proportion of the experimental spectra do not lead to a confident identification score due to inappropriate parameters or scoring schemes of the applied analysis software. The swissPIT (Swiss Protein Identification Toolbox) project was initiated to provide the scientific community with an expandable multi-tool platform for automated and in-depth analysis of mass spectrometry data. The swissPIT uses multiple identification tools to automatic analyze mass spectra. The tools are concatenated as analysis workflows. In order to realize these calculation-intensive workflows we are using the Swiss Bio Grid infrastructure. A first version of the web-based front-end is available (http://www.swisspit.cscs.ch) and can be freely accessed after requesting an account. The source code of the project will be also made available in near future.},
	keywords = {grid computing, JOpera, scientific workflow management},
	url = {http://www.ncbi.nlm.nih.gov/pubmed/17476043},
	author = {Andreas Quandt and Patricia Hernandez and Peter Kunzst and Cesare Pautasso and Marc Tuloup and Ron D. Appel}
}
@article {119,
	title = {Developing scientific workflows from heterogeneous services},
	journal = {SIGMOD Rec.},
	volume = {35},
	year = {2006},
	month = {June},
	pages = {22{\textendash}28},
	abstract = {Scientific Workflows (SWFs) need to utilize components and applications in order to satisfy the requirements of specific workflow tasks. Technology trends in software development signify a move from component-based to service-oriented approach, therefore SWF will inevitably need appropriate tools to discover and integrate heterogeneous services. In this paper we present the SODIUM platform consisting of a set of languages and tools as well as related middleware, for the development and execution of scientific workflows composed of heterogeneous services.},
	keywords = {JOpera, scientific workflow management},
	issn = {0163-5808},
	doi = {10.1145/1147376.1147380},
	author = {Aphrodite Tsalgatidou and Georgios Athanasopoulos and Michael Pantazoglou and Cesare Pautasso and Thomas Heinis and Roy Gr{\o}nmo and Hoff Hj{\o}rdis and Arne-J{\o}rgen Berre and Magne Glittum and Simela Topouzidou}
}
@article {117,
	title = {JOpera: Autonomic Service Orchestration},
	journal = {IEEE Data Engineering Bulletin},
	volume = {29},
	year = {2006},
	month = {September},
	pages = {32-39},
	keywords = {autonomic computing, JOpera, Web service composition},
	url = {ftp://ftp.research.microsoft.com/pub/debull/A06sept/issue1.htm},
	author = {Cesare Pautasso and Thomas Heinis and Gustavo Alonso}
}
@conference {jopera:2006:ccgrid,
	title = {Mirroring Resources or Mapping Requests: implementing WS-RF for Grid workflows},
	booktitle = {6th IEEE International Symposium on Cluster Computing and the Grid (CCGrid2006)},
	year = {2006},
	month = {May},
	address = {Singapore},
	abstract = {The Web Services Resource Framework (WS-RF) and the Web Services Notification (WS-N) specifications are a crucial component of Grid infrastructures. They provide a standardized interface to stateful services so that they can be managed remotely. There are already several implementations of these specifications and initial performance studies have compared them in terms of the overhead observed by a single client. In this paper we address the problem of implementing the WS-RF and WS-N specifications for large scale systems. In particular, we discuss how to implement WS-RF and WSN as the management interfaces to a Grid workflow engine. In the paper we describe and compare two different architectures for mapping resources to processes. The first one mirrors the state of the process as a resource. The second one maps the client requests to access the state of a resource embedded into the Grid workflow engine. We include an extensive performance evaluation, comparing the resulting systems in terms of scalability when servicing a large number of concurrent clients. },
	keywords = {grid computing, JOpera, scientific workflow management},
	doi = {10.1109/CCGRID.2006.69},
	author = {Thomas Heinis and Cesare Pautasso and Gustavo Alonso}
}
@inbook {jopera:2006:acbook,
	title = {A Self-Configuring Service Composition Engine},
	booktitle = {Autonomic Computing: Concepts, Infrastructure, and Applications},
	year = {2006},
	pages = {237-252},
	publisher = {CRC Press},
	organization = {CRC Press},
	chapter = {12},
	keywords = {autonomic computing},
	isbn = {0-8493-9367-1},
	doi = {10.1201/9781420009354.ch12},
	author = {Thomas Heinis and Cesare Pautasso and Gustavo Alonso},
	editor = {Manish Parashar and Salim Hariri}
}
@conference {jopera:2005:icws,
	title = {Autonomic Execution of Service Compositions},
	booktitle = {3rd International Conference on Web Services (ICWS 2005)},
	year = {2005},
	month = {July},
	publisher = {IEEE},
	organization = {IEEE},
	address = {Orlando, Florida},
	abstract = {An increasing amount of Web services are being implemented using process management tools and languages (BPML, BPEL, etc.). The main advantage of processes is that designers can express complex business conversations at a high level of abstraction, even reusing standardized business protocols. The downside is that the infrastructure behind the Web service becomes more complex. This is particularly critical for Web services that may be subjected to high variability in demand and suffer from unpredictable peaks of heavy load. In this paper we present a flexible architecture for process execution that has been designed to support autonomic scalability. The system runs on a cluster of computers and reacts to workload variations by altering its configuration in order to optimally use the available resources. Such changes happen automatically and without any human intervention. This feature completely removes the need for the manual monitoring and reconfiguration of the system, which in practice is a difficult and time-consuming operation. In the paper we describe the architecture of the system and present an extensive performance evaluation of its autonomic capabilities.},
	keywords = {autonomic computing, JOpera, Web service composition},
	doi = {10.1109/ICWS.2005.28},
	author = {Cesare Pautasso and Thomas Heinis and Gustavo Alonso}
}
@conference {jopera:2005:icac,
	title = {Design and Evaluation of an Autonomic Workflow Engine},
	booktitle = {2nd International Conference on Autonomic Computing (ICAC-05)},
	year = {2005},
	month = {June},
	pages = {27 - 38},
	publisher = {IEEE},
	organization = {IEEE},
	address = {Seattle, Washington},
	abstract = {In this paper we present the design and evaluate the performance of an autonomic workflow execution engine. Although there exist many distributed workflow engines, in practice, it remains a difficult problem to deploy such systems in an optimal configuration. Furthermore, when facing an unpredictable workload with high variability, manual reconfiguration is not an option. Thanks to its autonomic controller, the engine features self-configuration, self-tuning and self-healing properties. The engine runs on a cluster of computers using a tuple space to coordinate its various components. Its autonomic controller monitors its performance and responds to workload variations by altering the configuration. In case failures occur, the controller can recover the workflow execution state from persistent storage and migrate it to a different node of the cluster. Such interventions are carried out without any human supervision. As part of the results of our performance evaluation, we compare different autonomic control strategies and discuss how they can automatically tune the system},
	keywords = {automatic configuration, autonomic computing, JOpera, Web service composition},
	doi = {10.1109/ICAC.2005.21},
	author = {Thomas Heinis and Cesare Pautasso and Gustavo Alonso}
}
@conference {jopera:2005:escience,
	title = {Publishing Persistent Grid Computations as WS Resources},
	booktitle = {1st IEEE International Conference on e-Science and Grid Computing (e-Science 2005)},
	year = {2005},
	month = {December},
	publisher = {IEEE},
	organization = {IEEE},
	address = {Melbourne, Australia},
	abstract = {Grid services can be composed into processes, providing a high level definition of the computations involved in terms of their data exchanges and control flow dependencies. We show how processes themselves can be efficiently published as Grid services by mapping the persistent state of the process executions to standard compliant interfaces as defined by the Web Services Resource Framework (WS-RF). Mapping processes to resources is a fundamental step to enable recursive Grid service composition, where composite Grid services are themselves published as services. This gives processes a standardized and wellunderstood interface that enables their management, monitoring, steering and adaptation. Additionally it eases their reusability and simplifies integration into existing Grid applications and portals. In order to determine the mapping{\textquoteright}s overhead, we include the results of a comprehensive performance evaluation.},
	keywords = {grid computing, JOpera, scientific workflow management},
	doi = {10.1109/E-SCIENCE.2005.67},
	author = {Thomas Heinis and Cesare Pautasso and Oliver Deak and Gustavo Alonso}
}
