Design a Resource Allocation Service

You are tasked with designing a resource allocation service for a company that manages a large number of servers.

Each server's capabilities and configurations are described by up to 1000 feature flags, such as OS, CPU, memory, and storage size.

Users of this service will request, reserve, and release (i.e., un-reserve or deallocate) these servers based on the feature flags. The service must efficiently match these requests with available servers.