One of the key challenges in the data center today is the efficient use of data-center resources while providing services with service-level objectives (SLOs). The primary reason for the challenge is the dynamism in workload requirements over time. We propose dynamic instantiation of virtual caching appliances (caches as virtual machines) to handle the dynamism in workloads and thereby support storage SLOs efficiently. We have developed an SLO-based automation framework called Dynamite for cache instantiation, that includes low-overhead techniques to: determine the workloads that would benefit from caching, determine the appropriate cache size for these workloads, instantiate the cache and non-disruptively migrate the application, and finally warm the cache to quickly return to acceptable service levels. We have evaluated the effectiveness of the individual techniques using a variety of I/O traces and find that they are highly accurate despite approximations that significantly reduce monitoring overheads. And finally, the approach actually works! Using the complete pipeline on a case study involving interfering workloads shows that service levels can be met while utilizing resources efficiently.

Bio: Lakshmi N. Bairavasundaram is a member of technical staff in the Advanced Technology Group at NetApp. His research interests include storage systems, file systems, storage and data management, and fault tolerance. Lakshmi currently focuses on storage and data management abstractions and techniques. He joined NetApp after completing his Ph.D. in Computer Sciences (2008) at the University of Wisconsin-Madison under the supervision of Prof. Andrea Arpaci-Dusseau and Prof. Remzi Arpaci-Dusseau.