Publications

Journal Publications

• Spyridon V. Gogouvitis, Kleopatra Konstanteli, Stefan Waldschmidt, George Kousiouris, Gregory Katsaros, Andreas Menychtas, Dimosthenis Kyriazis and Theodora Varvarigou, "Workflow management for soft real-time interactive applications in virtualized environments," Future Generation Computer Systems, Volume 28, Issue 1, January 2012, Pages 193-209, ISSN 0167-739X, DOI:10.1016/j.future.2011.05.017. Abstract Notice

  Many applications, especially the ones implementing multi-user collaborative environments, fall within the context of soft real-time systems in which only small deviations from timing constraints are allowed. The advancements in distributed computing have made it possible to follow a service-oriented approach, taking advantage of the benefits this provides. In this context, applications consist of soft real-time critical application service components that interact with each other to provide the corresponding application functionality, forming application workflows. In this paper we present a new architectural design and implementation of a Workflow Management approach. This approach covers enacting soft real-time application service components according to a workflow description language, synchronizing the application components, monitoring the execution and reacting to events within a distributed virtualized environment. We also demonstrate the operation of the implemented mechanism and evaluate its effectiveness using an application scenario with soft real-time interactivity characteristics, namely Film Post-production, under realistic settings.

  NOTICE: this is the author's version of a work that was accepted for publication in Future Generation Computer Systems. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. "

• Tommaso Cucinotta, Fabio Checconi, George Kousiouris, Kleopatra Konstanteli, Spyridon Gogouvitis, Dimosthenis Kyriazis, Theodora Varvarigou, Alessandro Mazzetti, Zlatko Zlatev, Juri Papay, Michael Boniface, Soren Berger, Dominik Lamp, Thomas Voith, Manuel Stein. "Virtualised e-Learning on the IRMOS Real-time Cloud," accepted on Springer Service Oriented Computing and Applications. Abstract

  This paper presents the real-time virtualized Cloud infrastructure that was developed in the context of the IRMOS European Project. The paper shows how different concepts, such as real-time scheduling, QoS-aware network protocols, and methodologies for stochastic modelling and run-time provisioning, were practically combined to provide strong performance guarantees to soft real-time interactive applications in a virtualized environment.The efficiency of the IRMOS Cloud is demonstrated by two real interactive e-Learning applications, an e-Learning mobile content delivery application and a virtual world e-Learning application.

Book Chapters

• Spyridon V. Gogouvitis, Kleopatra Konstanteli, Dimosthenis Kyriazis, Gregory Katsaros, Tommaso Cucinotta and Michael Boniface. "Workflow Management Systems in Distributed Environments," Achieving Real-Time in Distributed Computing: From Grids to Clouds. IGI Global, 2012 ISBN13: 9781609608279, pp. 115-132. DOI:10.4018/978-1-60960-827-9.ch007. Copyright

  NOTICE: This chapter appears in "Achieving Real-Time in Distributed Computing: From Grids to Clouds" edited by Dimosthenis Kyriazis, Theodora Varvarigou and Kleopatra G. Konstanteli Copyright 2012, IGI Global, www.igi-global.com. Posted by permission of the publisher.

• Tommaso Cucinotta and Spyridon V. Gogouvitis. "Real-Time Attributes in Operating Systems," Achieving Real-Time in Distributed Computing: From Grids to Clouds. IGI Global, 2012, ISBN13: 9781609608279, pp. 275-287. DOI:10.4018/978-1-60960-827-9.ch015. Copyright

  NOTICE: This chapter appears in "Achieving Real-Time in Distributed Computing: From Grids to Clouds" edited by Dimosthenis Kyriazis, Theodora Varvarigou and Kleopatra G. Konstanteli Copyright 2012, IGI Global, www.igi-global.com. Posted by permission of the publisher.

Conferences

• Athanasios Voulodimos, Spyridon Gogouvitis, Nikoletta Mavrogeorgi, Roman Talyansky, Dimosthenis Kyriazis, Stefanos Koutsoutos, Vasileios Alexandrou,Elliot Kolodner, Per Brand, Theodora Varvarigou, "A Unified Management Model for Data Intensive Storage Clouds," IEEE First International Symposium on Network Cloud Computing and Applications, Toulouse, France, November 21-23, 2011. DOI

• Spyridon V. Gogouvitis, George Kousiouris, George Vafiadis, Hillel Kolodner, Dimosthenis Kyriazis, "OPTIMIS and VISION Cloud: How to manage data in clouds," Cloud Computing: Project and Initiatives - 2011. Collocated with: Euro-Par 2011 International Conference, Bordeaux, France, August 30th 2011.

• Hillel Kolodner, Dalit Naor, Sivan Tal, Stefanos Koutsoutos, Nikoletta Mavrogeorgi, Spyridon Gogouvitis, Dimosthenis Kyriazis, Eliot Salant, "Data-intensive Storage Services on Clouds: Limitations, Challenges and Enablers," eChallenges e-2011 Conference, Florence, Italy, October 27th 2011.

• Tommaso Cucinotta, Spyridon Gogouvitis, Kleopatra Kostanteli, "SLAs in Virtualized Cloud Computing Infrastructures with QoS Assurance," in Proceedings of the International Workshop on eContracting in the Clouds, co-located with the eChallenges 2011 Conference, Florence, Italy, October 27th 2011.

• Andreas Menychtas, Dimosthenis Kyriazis, Spyridon V. Gogouvitis, Karsten Oberle, Thomas Voith, Georgina Gallizo, Soren Berger, Eduardo Oliveros, Mike J. Boniface, "A Cloud Platform for Real-time Interactive Applications," CLOSER 2011, 2011.

• Elliot K. Kolodner, Sivan Tal, Dimosthenis Kyriazis, Dalit Naor, Miriam Allalouf, Lucia Bonelli, Per Brand, Albert Eckert, Erik Elmroth, Spyridon V. Gogouvitis, Danny Harnik, Francisco Hernandez, Michael C. Jaeger, Ewnetu Bayuh Lakew, Jose Manuel Lopez, Mirko Lorenz, Alberto Messina, Alexandra Shulman-Peleg, Roman Talyansky, Athanasios Voulodimos, Yaron Wolfsthal, "A Cloud Environment for Data-intensive Storage Services," to appear in Third IEEE International Conference on Cloud Computing Technology and Science (IEEE CloudCom 2011), 2011. Copyright

  Copyright 2011 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

• Athanasios S. Voulodimos, Dimosthenis P. Kyriazis, Spyridon V. Gogouvitis, Anastasios D. Doulamis, Dimitrios I. Kosmopoulos, Theodora A. Varvarigou, "QoS-oriented Service Management in Clouds for Large Scale Industrial Activity Recognition," to appear in Third International Conference of Soft Computing and Pattern Recognition (SoCPaR 2011), 2011. Copyright

  Copyright 2011 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

• George Kousiouris, Dimosthenis Kyriazis, Spyridon V. Gogouvitis, Andreas Menychtas, Kleopatra Konstanteli and Theodora A. Varvarigou, "Translation of Application-level Terms to Resource-level attributes across the Cloud Stack Layers," Workshop on Management of Cloud Systems (MoCS 2011), in conjunction with the 16th IEEE Symposium on Computers and Communications (ISCC 2011), 2011. Copyright

  Copyright 2011 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

• Spyridon V. Gogouvitis, Kleopatra Konstanteli, Dimosthenis Kyriazis, Theodora Varvarigou, "An Architectural Approach for Event-Based Execution Management in Service Oriented Infrastructures," 12th International Symposium on Symbolic and Numeric Algorithms for Scientific Computing (SYNASC), 2010. DOI Abstract Copyright

  In order to enable interactive applications to benefit from the offerings of the Cloud paradigm, factors such as QoS and event handling need to be taken into consideration in the development of new platforms. In this paper we propose a hierarchical Execution Management System Architecture that enables the execution of real-time interactive applications on SOIs by providing the required QoS levels.

  Copyright 2010 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

• Spyridon V. Gogouvitis, Kleopatra Konstanteli, George Kousiouris, Gregory Katsaros, Dimosthenis Kyriazis, Theodora Varvarigou, "A Service Oriented Architecture for achieving QoS-aware Workflow Management in Virtualized Environments," 6th International Conference on Network and Service Management (CNSM 2010), Niagra Falls, Canada, October 2010. Acceptance Rate 15.3% DOI Abstract Copyright

  The advancements in distributed computing have driven the emergence of service-based infrastructures that allow for on-demand provision of ICT assets. Taking into consideration the complexity of distributed environments, significant challenges exist in providing and managing the offered on-demand resources with the required level of Quality of Service (QoS), especially for real-time interactive multimedia applications. Common to these applications is the service-oriented approach being followed, thus applications consist of application service components that interact in order to provide the corresponding application functionality. In this paper we present an architectural design of a complete Workflow Management System (WfMS) for enacting application service components that have been deployed in a Virtualized Environment. The WfMS aims at synchronizing the application components, monitoring their execution and handling faults while adhering to the QoS requirements of the application.

  Copyright 2010 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

• Georgina Gallizo, Roland Kubert, Karsten Oberle, Klaus Satzke, Spyridon V. Gogouvitis, Gregory Katsaros, and Eduardo Oliveros, "A Service Level Agreement Management Framework for Real-time Applications in Cloud Computing Environments," 2nd International ICST Conference on Cloud Computing (CloudComp 2010) Barcelona, Spain October 26 - 28, 2010

• George Kousiouris, Dimosthenis Kyriazis, Kleopatra Konstanteli, Spyridon Gogouvitis, Gregory Katsaros and Theodora Varvarigou, "A Service-Oriented Framework for GNU Octave-Based Performance Prediction," IEEE Services Computing Conference (SCC) 2010, July 5-10, Miami, USA. DOI Copyright

  Copyright 2010 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

• Michael Boniface, Bassem Nasser, Juri Papay, Stephen C. Phillips, Arturo Servin, Xiaoyu Yang, Zlatko Zlatev, Spyridon V. Gogouvitis, Gregory Katsaros, Kleopatra Konstanteli, George Kousiouris, Andreas Menychtas, Dimosthenis Kyriazis, "Platform-as-a-Service Architecture for Real-Time Quality of Service Management in Clouds," iciw, pp.155-160, 2010 Fifth International Conference on Internet and Web Applications and Services, 2010. DOI Abstract Copyright

  Cloud computing offers the potential to dramatically reduce the cost of software services through the commoditization of information technology assets and on-demand usage patterns. However, the complexity of determining resource provision policies for applications in such complex environments introduces significant inefficiencies and has driven the emergence of a new class of infrastructure called Platform-as-a-Service (PaaS). In this paper, we present a novel PaaS architecture being developed in the EU IST IRMOS project targeting real-time Quality of Service (QoS) guarantees for online interactive multimedia applications. The architecture considers the full service lifecycle including service engineering, service level agreement design, provisioning and monitoring. QoS parameters at both application and infrastructure levels are given specific attention as the basis for provisioning policies in the context of temporal constraints. The generic applicability of the architecture is being verified and validated through implemented scenarios from three important application sectors (film post-production, virtual augmented reality for engineering design, collaborative e-Learning in virtual worlds).

  Copyright 2010 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

• Theodoros Polychniatis, Andreas Menychtas, Spyridon V. Gogouvitis, George Kousiouris, Kleopatra Konstanteli, Dimosthenis Kyriazis, Theodora Varvarigou, "Framework Services for Real-time SOIs,", EGEE'08 Conference, Harbiye Askeri Museum, Istanbul - Turkey, 22-26 September, 2008.

• Spyridon V. Gogouvitis, George Kousiouris, Kleopatra Konstanteli, Theodoros Polychniatis, Andreas Menychtas, Dimosthenis Kyriazis, Theodora A. Varvarigou, "Realtime-enabled workflow management in service oriented infrastructures," Proceedings of the 1st ACM Workshop on Analysis and Retrieval of Events/Actions and Workflows in Video Streams, AREA 2008, Vancouver, British Columbia, Canada, October 31, 2008. DOI Abstract

  Many applications, and especially the ones implementing multi-user collaborative environments, fall within the context of soft real time systems in which only small deviations from timing constraints are allowed. Furthermore, there is a growing trend that such applications are deployed in Service Oriented Infrastructures (SOIs), so as to take advantage of the capabilities that SOIs provide. In such an environment, the aforementioned applications are divided into multiple services within workflows. The dynamic nature of SOIs and their inability to adjust to the ever-changing resource availability and user demand poses an extra burden as workflow systems try to carry out more complex and mission-critical applications. In that frame, we discuss the work that has been carried out in the area of workflow management - developed to serve the needs of applications deployed in distributed environments, along with their limitations and potentials. Based on that, we present the research effort of the IRMOS EU-funded Project which advances the field of research in workflow management in order to support interactive real time applications on SOIs.