Selecting resource allocation policies and resolving resource conflicts

This invention describes a smart way to manage computing power in large data centers, like those used for cloud services. It uses several specialized managers working at the same time, each automatically picking the best strategy for giving out resources based on what tasks need to be done, who needs them, and how busy the data center is. Some managers might quickly assign resources, assuming everything will be fine (optimistic), while others might reserve resources carefully beforehand (pessimistic). If the quick assignments cause problems, the invention also includes ways to fix those conflicts. The claims specifically mention that the pessimistic method involves blocking resources, and the optimistic method does not.