1. A method of handling requests queued to servers based on a Quality of Service (QoS) criteria, the method comprising: grouping computing resources according to a QoS criteria, wherein there are at least two groups of computing resources, each group having a power management policy (PMP); receiving a plurality of requests from a plurality of devices; determining a service class for each request; queuing the each request to one of the at least two groups of computing resources based on the service class; processing the each request by the one of the at least two groups of computing resources; receiving a set of service queue information for a group of computing resources, wherein the set of service queue information comprises a queue depth and an arrival rate; determining whether the group of computing resources will satisfy the QoS criteria, wherein determining whether the group of computing resources will satisfy the QoS criteria comprises determining an average response time for incoming requests; and adjusting, in response to determining that the group of computing resources will not satisfy the QoS criteria, the PMP for the group of computing resources.