A web services system includes a plurality of computing nodes, each comprising a processor and memory coupled to the at least one processor. The computing nodes include a network device and a management service. The network device is configured to receive service requests directed to an application. The management service allocates resources to the network device, and is configured to measure usage of a plurality of different types of the resources by the network device, and to determine a value of resource utilization for the network device. The value is expressed according to a standard that represents all the different types of the resources, and the value is selected based on one of the different types of the resources that is most highly utilized by the network device.