Quality of Service in Distributed Systems

Speaker: Prof. Klara Nahrstedt
Date: April 22 + 23
Time: 09:30 - 17.00
Room: S3 06/348 (KOM seminar room)


Quality of Service is an important concept of many application domains, but especially for multimedia distributed applications such as movie on demand, tele-conferencing, news casting, tele-immersive group collaborations, multimedia mail system, distributed multimedia document processing, film editing and others. In the past, there has been a lot of QoS concepts development in the lower networking layers. However, over the past ten years, large body of work happened at the operating system and distributed system level with respect to QoS management. In a two days short course, we will discuss four major issues: (a) QoS Definition, Services, Protocols and Frameworks, (b) QoS Specification and Translations, (c) QoS Issues in Operating Systems, and (d) QoS Issues in Distributed Systems.

In the first part, we will discuss concepts, such as service classes, QoS operations in QoS management frameworks, corresponding resource operations and mechanisms to support QoS operations, design principles of QoS management frameworks and selected existing examples of QoS architectures and frameworks such as Upenn architecture, called OMEGA, Lancaster architecture, called QoS-A, and Columbia architecture QoSME.

In the second part, we will present, based on selected case studies from BBN, Columbia, HP, UIUC, (1) different specifications of QoS ranging from C-like structures, to XML-based QoS representations, and (2) QoS mappings between application QoS requirements and underlying system and network resource management systems, discussing importance of probing, profiling, and compilation services.

In the third part of the course, we will present operating system concepts that support QoS and multimedia applications. We will show various concepts, based on existing systems from UIUC, UT Austin, Microsoft, Stanford, CMU, such as (1) immediate and advanced reservation concepts in OS, (2) probing service, (3) power-awareness, (4) multi-processor support, and others.

In the forth part of the course, we will discuss QoS in distributed object computing, QoS-aware configuration and adaptation, QoS-aware resource allocation and reservation, QoS-aware service discovery, QoS-aware service composition and other QoS issues coming out of the grid, overlay and middleware system research results. The various QoS issues will be discussed in context of existing systems such as Globus, QuO, RealTime Corba, CANS, Darwin, Ninja, Sahara, Agilos, 2kQ, and others.

Prof. Klara Nahrstedt is currently an associate professor in the Department of Computer Science, University of Illinois at Urbana-Champaign. Over the last ten years she has been working on various research problems in the area of Quality of Service provisioning for real-time multimedia processing and communication systems and published over 100 papers in leading conferences and journals. She is the editor-in-chief of the ACM/Springer Multimedia Journal, as well as she has served on the editorial board of IEEE Transactions on Multimedia, Computer Networks Journal, Journal on Multimedia Applications and Tools, and ACM Computer Communication Review Journal. For her research results she was awarded the Early NSF Career Award, the Junior Xerox Award, IEEE Communication Society Leonard Abraham Award for Research Achie vements, and the Ralph and Catherine Fisher Professorship Chair.