Professor Umesh Bellur, Computer Science, Indian Institute of Technology, Bombay delivered a lecture on Fragmentation in Virtualized Data Centres. According to Professor Bellur, the Existing virtual machine (VM) placement schemes have measured their effectiveness by measuring how well they conserve either Physical Machine’s resources (CPU, memory) or the network resource but not both. However, real applications use all resource types to varying degrees. The result of applying existing placement schemes to VMs running real applications is a fragmented data centre where resources along one dimension become unusable even though they are available because of the unavailability of resources along with other dimensions. An example of this fragmentation is unusable CPU because of a bottlenecked network link from the physical machine which has available CPU. To date, evaluations of the efficacy of VM placement schemes have not recognized this fragmentation and it’s ill effects, let alone try to measure it and avoid it. In this talk, he first defined the term” relative resource fragmentation” and illustrate how it can be measured in a data centre. The metric put forth for capturing the degree of fragmentation is comprehensive and includes all key data centre resource types. He will then propose a scheme of minimizing this fragmentation so as to maximize the availability of an existing set of data centre resources. Results of empirical evaluations of his placement scheme compared to the existing network-based placement schemes has shown a reduction of fragmentation by as much as 15% and an increase in a number of successfully placed applications by up to 20%.

Umesh Bellur is a Professor in Computer Science at the Indian Institute of Technology, Bombay. His areas of research include virtualization and cloud computing, distributed event-based systems and data centre management. He has received the IBM Faculty award as well as the SAP Research innovation award for his work on autonomic management of enterprise applications as well as a number of grants from IBM, Motorola, Netapp and other leading enterprises for his work in virtualization and cloud computing. He recently completed a sabbatical from IIT Bombay and was a visiting professor at the Department of Computer Science at Purdue University. Prior to joining IIT Bombay, Professor Bellur was an entrepreneur in Silicon Valley where he co-founded Collation Inc. in 2001, that built software products to manage enterprise application deployments in large data centres. Collation was subsequently acquired by IBM in 2004. He has a PhD from Syracuse University.