1. A method, comprising: performing by a computer system that provides storage services to clients: receiving a plurality of requests to read or write data on behalf of one or more clients; servicing a portion of the requests, wherein the portion of the plurality of service requests that is serviced is dependent on a maximum request rate; determining that the rate at which the plurality of requests was received exceeds the maximum request rate; in response to said determining, adjusting the maximum request rate, wherein said adjusting is dependent on an observed data transfer rate required to satisfy the portion of the requests, and wherein the amount of data transferred in servicing each of the requests in the portion of the requests is non-uniform; and subsequent to said adjusting: receiving one or more additional requests to read or write data on behalf of the one or more clients; and servicing a portion of the additional requests, wherein the portion of the additional requests that is serviced is dependent on the adjusted maximum request rate.