| Internet services execute complex logic on heterogeneous and distributed server platforms for concurrent requests--- in short, they are complicated. Often subtle changes in request patterns or system configurations have unexpected and undesirable performance consequences. This dissertation demonstrates practical system management for Internet services that improves performance dependability, increases raw performance, and raises the performance-to-cost ratio in datacenters. In our approach, system management is guided by easy-to-understand and easy-to-apply models of a service's performance. These performance models are easy to understand, because they use real system properties that are common across many services to characterize application-level performance ( e.g., response time and throughput). They are easy to apply, because they are calibrated with system measurements that can be collected in practice. And they are useful in system management, because they predict what performance would be like if contemplated actions were taken. In particular, this dissertation presents case studies of our model-driven system management approach for actions frequently contemplated in practice, such as what if the component placement strategy were changed, what if the load balancing policy were changed, and what if services were consolidated. Experimental results with several Internet services under realistic operating conditions show the potential for model-driven system management. |
