Method and apparatus for determining latency between multiple servers and a client

An apparatus for determining latency between multiple servers and a client across a network in a computer environment, comprising:

• a module for receiving a request for a content server address from said client;
• a module for sending a latency metric request from a server to an appropriate probe server;
• a module for receiving a request for latency metrics on a probe server;
• wherein said latency metric request specifies a particular client;
• a latency management table;
• wherein said latency management table initially comprises a list of IP addresses along with corresponding Border Gateway Protocol (BGP) hop counts;
• a module for looking up the latency metric for said client in said latency management table;
• a module for sending said latency metric to the requesting server;
• a module for receiving latency metric data from said probe server at the requesting server;
• a module for determining an optimal content server for said client using said latency metric data;
• a module for sending said optimal content server's address to said client;
• wherein only the BGP hop count for said client in said latency management table is used for said latency metric upon an initial request for said client;
• and
• wherein the probe server determines a dynamic hop count and Round Trip Time (RTT) data for said client after the initial request, enters the dynamic hop count and RTT information into said latency management table, and uses the dynamic hop count and RTT information for said latency metric for subsequent requests for said client.

A program storage medium readable by a computer, tangibly embodying a program of instructions executable by the computer to perform method steps for determining latency between multiple servers and a client across a network in a computer environment, comprising the steps of:

• receiving a request for a content server address from said client;
• sending a latency metric request from a server to an appropriate probe server;
• receiving a request for latency metrics on a probe server;
• wherein said latency metric request specifies a particular client;
• wherein a latency management table initially comprises a list of IP addresses along with corresponding Border Gateway Protocol (BGP) hop counts;
• looking up the latency metric for said client in said latency management table;
• sending said latency metric to the requesting server;
• receiving latency metric data from said probe server at the requesting server;
• determining an optimal content server for said client using said latency metric data;
• sending said optimal content server's address to said client;
• wherein only the BGP hop count for said client in said latency management table is used for said latency metric upon an initial request for said client;
• and
• wherein the probe server determines a dynamic hop count and Round Trip Time (RTT) data for said client after the initial request enters the dynamic hop count and RTT information into said latency management table, and uses the dynamic hop count and RTT information for said latency metric for subsequent requests for said client.