Patent ID: 7349969

Claim:
An apparatus for using a phased learning approach for determining closest of s multiple content serving sites to a client DNS server in a computer network including: a memory; a query sender configured to, in a setup phase, store data as to transit times of each of the s multiple content serving sites in a table when the transit times are determined; a response time determiner coupled to the query sender and configured to, in an execution phase, determine a response time for each of n fastest content serving sites and m other content serving sites, the n fastest content serving sites chosen by examining the transit times of each of the s multiple content serving sites for which the transit times have already been determined and choosing n content serving sites with lowest transit times, the m other content serving sites including new content serving sites for which the transit times have not yet been determined and including one or more randomly selected content serving sites for which the transit times have already been determined, wherein n is less than s and greater than zero; and wherein the query sender is further configured to, in the execution phase, send queries to each of the n fastest content serving sites and m other content serving sites, timing the queries so that they arrive at each of the n fastest content serving sites and m other content serving sites at the same times by using the response time for each of the n fastest content serving sites and m other content serving sites; wherein transit times of each of the n fastest content serving sites and m other content serving sites determined in response to the timing the queries are stored in the table. (see page 15 of the specification for support).