System and method for directing clients to optimal servers in computer networks
A communication protocol includes one or more messages passed between Web routers over a reliable transmission protocol used for inter-Web router communication. These messages include information that allows the Web routers to dynamically update mappings of client addresses or address ranges to information object repository addresses based on client-to-server distance and server load. The mappings are preferably optimal mappings of the client addresses or address ranges to the information object repository addresses and the messages report updated distances from these information object repository addresses to the client addresses or address ranges. For example, the messages may report, for each updated distance, an associated client address or address range and/or an associated anchor address of a Web router co-located with an information object repository that is the subject of the message.
1. A method, comprising:
creating, at a first Web router of a network of Web routers, a network latency map for at least one of the Web routers of the network and a client communicatively coupled to the at least one Web router using internetwork connectivity information received at the first Web router through an inter-domain routing protocol; and
disseminating the network latency map from the first Web router to one or more neighbor Web routers of the first Web router through a reliable communication protocol used for inter-Web router communication messages exchanged via the network, wherein the network latency map specifies client-to-Web router latency information between the client and the at least one Web router based on the internetwork connectivity information and latency measurements of the first Web router; and
updating a client-to-server map in response to a network latency map update only if the network latency map update specifies a better mapping than the client-to-server map based on a first sequence number associated with the network latency map update being greater than a second sequence number associated with the client-to-server map, a first distance associated with the network latency map update being less than a second distance associated with the client-to-server map, or a first result of a hashing function computed using one or more parameters of the network latency map update is less than a second result of the hashing function computed using corresponding one or more parameters of the client-to-server map.
2. The method of claim 1 wherein the inter-domain routing protocol-includes a border gateway protocol.
3. The method of claim 1 further comprising using, the at least one Web router, the network latency map to produce the client-to-server map which specifies a most favored server for servicing information object requests by the client.
4. The method of claim 3 wherein the client-to-server map is produced by combining server load information with information specified by the network latency map.
5. The method of claim 4 wherein the combining to produce the client-to-server map comprises adding.
6. The method of claim 5 wherein the server load and the distance between the client and the at least one Web router are measured in common units.
7. The method of claim 5 further comprising updating the client-to-server map in response to one or more of a server load change or a network latency map update.
8. The method of claim 7 wherein the network latency map update is transmitted as one of the inter-Web router communication messages exchanged via the network.
9. The method of claim 7 wherein in response to updating the client-to-server map, a client-to-server map update is transmitted as one of the inter-Web router communication messages exchanged via the network.
10. The method of claim 1 wherein the network latency map update specifies a better mapping than the client-to-server map when the first sequence number associated with the network latency map update is greater than the second sequence number associated with the client-to-server map.
11. The method of claim 1 wherein the network latency map update specifies a better mapping than the client-to-server map when the first distance associated with the network latency map update is less than the second distance associated with the client-to-server map.
12. The method of claim 1 wherein the network latency map update specifies a better mapping than the client-to-server map when the first result of a hashing function computed using one or more parameters of the network latency map update is less than the second result of the hashing function computed using corresponding one or more parameters of the client-to-server map.