Systems and method for the management and processing of resource requests by a service provider, such as a content delivery network (“CDN”) service provider, on behalf of a content provider are provided. The CDN service provider can measure the performance associated with the delivery of resources to a requesting client computing devices from various computing devices associated with the CDN service provider. In one embodiment, a client computing device can execute code, such as scripts, that cause the client computing device to transmit requests to different computing devices associated with the CDN service provider's domain. Information associated with the processing of the responses can be used to measure CDN service provider latencies.