Abstract: A system for implementing closed-loop and dynamic capacity management in a web-scale data center is provided. In some embodiments, the method includes a local feedback loop for local system data collection and reconfiguration process that is responsive to inputs received from a global sizing system, where the global sizing system maintains local system data collected at a plurality of systems and transferred to the global sizing system using a data collection feedback mechanism. In some embodiments, the global sizing system manages a set of data representing best practices, and performs data analysis on the local system data collected at a plurality of systems in order to determine if there are any updates to the dataset for the best practices data. Finally, the global sizing system transmits the best practices data to the local system for analysis of the local systems based on the best practices data.