Distributed selection of a content server
A method for directing a client to a content server containing desired content by providing the client with an address shared by a plurality of content servers, each of which has a copy of the desired content. The client is then served from an optimal, or closest available content server selected from the plurality of content servers. This optimal content server is selected on the basis of an optimal path from the client to the shared address.
1. A method for directing a client to a content server containing desired content, said method comprising:
at an origin server separate from the content server, receiving a request from a client for desired content;
in response to the request,
identifying an autonomous system having a plurality of content servers, each of the content servers having a copy of the desired content, and
providing said client with a shared address, said shared address being common to said content servers; and
serving said client from an optimal content server selected from said plurality of content servers, said optimal content server having been selected on the basis of an optimal path from said client to said shared address.
2. The method of claim 1 wherein serving said client from an optimal content server comprises:
receiving a request form said client to connect to a content server at said shared address;
identifying an optimal path between said client and said shared address; and
designating a content-server on said optimal path to be said optimal content-server.
3. The method of claim 2 further comprising directing said client to reach said optimal content-server by following said optimal path.
4. The method of claim 1 further comprising providing said shared address to a BGP router.
5. A content delivery system comprising:
an autonomous system including a first content server and a second content server having content in common with said first content server;
an origin server separate from the autonomous system for providing an address to a client in response to a request for content, the address identifying said autonomous system;
a first router for relaying messages to said first content server; and
a second router for relaying messages to said second content server.
6. The content delivery system of claim 5 wherein said first router is a BGP router.
7. A computer-readable medium having encoded thereon software for directing a client to a content server containing desired content, said software comprising instructions for:
at an origin server separate from the content server, receiving a request from a client for desired content;
in response to the request,
identifying an autonomous system having a plurality of content servers, each of the content servers having a copy of the desired content, and
providing said client with a shared address, said shared address being common to said content servers; and
serving said client from an optimal content server selected from said plurality of content servers, said optimal content server having been selected on the basis of an optimal path from said client to said shared address.
8. The computer-readable medium of claim 7 wherein said instructions for serving said client from an optimal content server comprise instructions for:
receiving a request from said client to connect to a content server at said shared address;
identifying an optimal path between said client and said shared address; and
designating a content-server on said optimal path to be said optimal content-server.
9. The computer-readable medium of claim 8 wherein said software further comprises instructions for directing said client to reach said optimal content-server by following said optimal path.
10. The computer-readable medium of claim 7 said software further comprises instructions for grouping said plurality of content servers into an autonomous system.
11. The computer-readable medium of claim 10 said software further comprises instructions for said shared address to a BGP router.