Research

When I started the Master's program at FIU, I was assigned to the TRAP/J project (Transparent Generation of Adaptable Java Programs). Shortly after that, I moved to the area of Grid computing, where I worked on a hierarchical, peer-to-peer architecture for Grid meta-schedulers. During that time, and with the new improvements in the field of virtualization and Cloud computing, we started exploring how Virtual Machines could be used as containers for running scientific jobs. I am currently working on a Infrastructure as a Service manager capable of orchestrating the provisioning and instantiation of Distributed Ensembles of Virtual Appliances (DEVAs) in the cloud

There are many unresolved challenges when managing virtual infrastructure in the Cloud: first, providers need to give guarantees about how virtual elements will behave during runtime, so that users can estimate their workloads' performance once instantiated in the remote resources. Another challenge consists in granting capabilities to Cloud providers so that they can elastically manage their hosted virtual resources. Existing methods such as dynamic resource allocation or live VM migration are not enough when performed in isolation: there is the need to consider groups of appliances as a whole when scaling resources. Finally, there is a lack of mechanisms for different providers to delegate user demands to other sites when they can't respond to them.

Publications

David Villegas, Athanasios Antoniou, S. Masoud Sadjadi and Alexandru Iosup. An Analysis of Provisioning and Allocation Policies for Infrastructure-as-a-Service Clouds. To appear in Proceedings of 12th IEEE/ACM International Symposium on Cluster, Cloud and Grid Computing (CCGrid 2012)

David Villegas, Norman Bobroff, Ivan Rodero, Javier Delgado, Yanbin Liu, Aditya Devarakonda, Liana Fong, S. Masoud Sadjadi and Manish Parashar. Cloud Federation in a Layered Service Model. In Journal of Computer and System Sciences, January 2012 ISSN 0022-0000, 10.1016/j.jcss.2011.12.017.

David Villegas and S. Masoud Sadjadi. Mapping Non-Functional Requirements to Cloud Applications. In Proceedings of the 2011 International Conference on Software Engineering and Knowledge Engineering (SEKE 2011), pages 527-532, Miami, Florida, July 2011.

David Villegas and S. Masoud Sadjadi. DEVA: Distributed Ensembles of Virtual Appliances in the Cloud. In Proceedings of the 17th Euro-Par Conference (Euro-Par 2011), pages 467-478, Bordeaux, France, 2011. [pdf]

David Villegas, Ivan Rodero, Liana Fong, Norman Bobroff, Yanbin Liu, Manish Parashar, and S. Masoud Sadjadi. Handbook of Cloud Computing, chapter The Role of Grid Computing Technologies in Cloud Computing. Springer, 2010 (in press; 36 pages; single-spaced).

Yanbin Liu, David Villegas, Norman Bobroff, Liana Fong, Ivan Rodero, Seetharami Seelam, and S. Masoud Sadjadi. An experimental system for grid meta-broker evaluation. In Proceedings of the ACM Large-scale System and Application Performance workshop (LSAP2009) of the International Symposium on High Performance Distributed Computing (HPDC 2009), pages 11-18, Munich, Germany, June 2009. [ bib | .pdf ]

Yanbin Liu, S. Masoud Sadjadi, Liana Fong, Ivan Rodero, David Villegas, Selim Kalayci, Norman Bobroff, and Juan Carlos Martinez. Enabling autonomic meta-scheduling in grid environments. In Proceedings of the 5th IEEE International Conference on Autonomic Computing (ICAC-2008), pages 199-200, Chicago, IL, June 2008. [ bib | .pdf ]

Hector A. Duran Limon, S. Masoud Sadjadi, Raju Rangaswami, Shu Shimizu, Liana Fong, Rosa M. Badia, Pat Welsh, Sandeep Pattnaik, Anthony Praino, Javier Figueroa, Javier Delgado, Xabriel J. Collazo-Mojica, David Villegas, Selim Kalayci, Gargi Dasgupta, Onyeka Ezenwoye, Khalid Saleem, Juan Carlos Martinez, Ivan Rodero, Shuyi Chen, Javier Muñoz, Diego Lopez, Julita Corbalan, Hugh Willoughby, Michael McFail, Christine Lisetti, and Malek Adjouadi. Grid enablement and resource usage prediction of weather research and forecasting. In Proceedings of the Collaborative and Grid Computing Technologies Workshop, page 4, Cancun, Mexico, April 2008. [ bib ]

Norman Bobroff, Liana Fong, Selim Kalayci, Yanbin Liu, Juan Carlos Martinez, Ivan Rodero, S. Masoud Sadjadi, and David Villegas. Enabling interoperability among meta-schedulers. In Proceedings of 8th IEEE International Symposium on Cluster Computing and the Grid (CCGrid-2008), pages 306-315, Lyon, France, 2008. [ bib | .pdf ]

S. Masoud Sadjadi, Liana Fong, Rosa M. Badia, Javier Figueroa, Javier Delgado, Xabriel J. Collazo-Mojica, Khalid Saleem, Raju Rangaswami, Shu Shimizu, Hector A. Duran Limon, Pat Welsh, Sandeep Pattnaik, Anthony Praino, David Villegas, Selim Kalayci, Gargi Dasgupta, Onyeka Ezenwoye, Juan Carlos Martinez, Ivan Rodero, Shuyi Chen, Javier Muñoz, Diego Lopez, Julita Corbalan, Hugh Willoughby, Michael McFail, Christine Lisetti, and Malek Adjouadi. Transparent grid enablement of weather research and forecasting. In Proceedings of the 15th ACM Mardi Gras conference: From lightweight mash-ups to lambda grids: Understanding the spectrum of distributed computing requirements, applications, tools, infrastructures, interoperability, and the incremental adoption of key capabilities, Baton Rouge, Louisiana, USA, January 2008. (8 pages). [ bib | .pdf ]

Xing Hang, David Villegas Castillo, S. Masoud Sadjadi, and Heidi Alvarez. Formative assessment of the effectiveness of collaboration in GCB. In Proceedings of the International Conference on Information Society (i-Society 2007), pages 103-110, Merrillville, Indiana, USA, October 2007. [ bib | .pdf ]

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