Improving and Tuning the Performance of Server Systems

OF THE DISSERTATION Improving and Tuning the Performance of Server Systems by Cheng Li Dissertation Directors: Thu D. Nguyen and Ricardo Bianchini Modern server systems incorporate complex hardware and software technologies, such as solidstate drives and software virtualization. Maximizing the performance of these complex systems involves many challenges. For example, their performance can often be strongly affected by multiple configuration parameters. At the same time, service providers using these servers often have complex performance objectives, such as achieving multiple performance targets at the same time. In this dissertation, we address three such challenges: improving space efficiency in solidstate drives used as caches (and consequently performance) for storage arrays, reducing performance variability in virtualized systems, and engineering performance to meet multiple performance targets. We built three systems to tackle these challenges concretely. The first system, called Nitro, uses deduplication and local compression to increase the effective (solid-state) cache size of network-attached storage systems, improving performance and space efficiency while minimizing total cost. The second system, called VirtualFence, leverages solid-state drives and non-work-conserving scheduling to provide consistent I/O performance in virtualized multi-tenant systems. The third system, called OpTune, mitigates the complexity of