Systems, methods, and apparatus for managing resources assigned to an application or service. A resource manager maintains a set of workload classes and classifies workloads using workload signatures. In specific embodiments, the resource manager minimizes or reduces resource management costs by identifying a relatively small set of workload classes during a learning phase, determining preferred resource allocations for each workload class, and then during a monitoring phase, classifying workloads and allocating resources based on the preferred resource allocation for the classified workload. In some embodiments, interference is accounted for by estimating and using an "interference index".