Routing for origin-facing points of presence

• US 10,270,878 B1
• Filed: 11/10/2015
• Issued: 04/23/2019
• Est. Priority Date: 11/10/2015
• Status: Active Grant

• Current Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Original Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Inventors: Uppal, Hardeep Singh, Baldwin, Matthew Graham
• Primary Examiner(s): Rubin, Blake J
• Application Number:
  US14/937,762
• Time in Patent Office: 1,260 Days
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/126 minimising geographical or physical path length
• CPC Class Codes: H04L 67/01 Protocols
• CPC Class Codes: H04L 67/52 specially adapted for the location of the user terminal
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching
• CPC Class Codes: H04L 67/5681 Pre-fetching or pre-delivering data based on network characteristics
• CPC Class Codes: H04L 67/63 Routing a service request depending on the request content or context

Abstract

Systems and methods are described to enable and manage the use of origin-facing points of presence (“POPs”) within a content delivery network (“CDN”). Origin-facing POPs can provide a second-tier caching mechanisms in a CDN, such that cache misses occurring at first-tier POPs may be processed by using information maintained at the origin-facing POPs, rather than requiring interaction with an origin server. Associations between origin-facing POPs and origin servers may be automatically created based on a distance between the respective origin-facing POPs and origin servers, such that an operator of the origin server is not required to specify a location of an origin facing POP. First-tier POPs may selectively retrieve content from origin-facing POPs in instances where the origin-facing POP is expected to provide the content more rapidly than the origin server.

Claims

1. A content delivery system comprising:

a client-facing point of presence (“

POP”

) comprising at least one computing device associated with a first non-transitory data store, the client-facing POP configured to receive requests for content associated with an origin server, and when the content is cached within the first non-transitory data store, return the content; and

an origin-facing POP comprising at least one computing device associated with a second non-transitory data store, the origin-facing POP assigned to maintain the content associated with the origin server within the second non-transitory data store, the origin-facing POP configured to receive requests for the content associated with the origin server, and when the content is cached within the second non-transitory data store, return the content;

wherein the client-facing POP is further configured to;

obtain routing information identifying a network distance between the client-facing POP and the origin-facing POP and a network distance between the client-facing POP and the origin server;

receive a request for content not cached within the first non-transitory data store of the client-facing POP;

select either the origin-facing POP or the origin server as a content source for the requested content that is not cached within the first non-transitory data store of the client-facing POP, wherein either the origin-facing POP or the origin server is selected as the content source based at least in part on a comparison of the network distance between the client-facing POP and the origin-facing POP and the network distance between the client-facing POP and the origin server;

retrieve the requested content from the content source; and

return the requested content in response to the request.

2. The content delivery system of claim 1, wherein the origin-facing POP is further configured, when requested content is not cached within the second non-transitory data store, to retrieve the requested content from the origin server.

3. The content delivery system of claim 1 further comprising a POP manager including one or more computing devices configured with computer-executable instructions to assign the origin-facing POP to maintain the content associated with the origin server based at least in part on a network distance between the origin-facing POP and the origin server.

4. The content delivery system of claim 1, wherein the client-facing POP is configured to obtain the routing information at least partly by monitoring communications between the client-facing POP and the origin-facing POP.

5. The content delivery system of claim 1, wherein the client-facing POP is configured to obtain the routing information at least partly by transmitting a network probe to the origin-facing POP.

6. The content delivery system of claim 1, wherein the routing information comprises a first set of routing information identifying network distances between the client-facing POP and a plurality of origin-facing POPs on the content delivery system and a second set of routing information identifying network distances between the client-facing POP and a plurality of origin servers.

7. The content delivery system of claim 1, wherein the client-facing POP is configured to generate a routing table for the requested content at least partly by combining the first and second sets of routing information, and wherein the comparison of the network distance between the client-facing POP and the origin-facing POP and a network distance between the client-facing POP and the origin server is conducted by selecting a lowest network distance identified within the routing table.

8. A computer-implemented method comprising:

at a client-facing point of presence (“

POP”

) within a content delivery network;

obtaining a request for content associated with an origin server;

determining that the content is not maintained at the client-facing POP;

obtaining first routing information identifying a network distance between the client-facing POP and the origin server;

obtaining second routing information identifying a network distance between the client-facing POP and an origin-facing POP on the content delivery network associated with the origin server;

selecting either the origin-facing POP or the origin server as a content source for the requested content that is not maintained at the client-facing POP based at least in part on a comparison of the network distance between the client-facing POP and the origin server, as identified in the first routing information, and a network distance between the client-facing POP and the origin-facing POP, as identified in the second routing information;

retrieving the requested content from the content source; and

returning the requested content in response to the request.

9. The computer-implemented method of claim 8 further comprising:

receiving a request from a user associated with the origin server to utilize a secondary POP on the content delivery network; and

selecting the origin-facing POP as the secondary POP based at least in part on a network distance between the origin-facing POP and the origin server.

10. The computer-implemented method of claim 8, wherein the origin-facing POP is one of a plurality of origin-facing POPs associated with the origin server, and wherein the second routing information identifies a network distance between the client-facing POP and individual origin-facing POPs of the plurality of origin-facing POPs.

11. The computer-implemented method of claim 8, wherein the first routing information further indicates a capacity of the origin server, and wherein selecting either the secondary POP or the origin server as a preferred content source for the requested content is further based at least in part on the capacity of the origin server.

12. The computer-implemented method of claim 8, wherein selecting either the origin-facing POP or the origin server as a preferred content source for the requested content comprises combining at least a portion of the first and second routing information to form a routing table for the requested content, and wherein the preferred content source is selected based at least partly on the routing table.

13. The computer-implemented method of claim 8, wherein the content source corresponds to the origin-facing POP, and wherein the method further comprises:

determining that the requested content is not available at the origin-facing POP;

retrieving, at the origin-facing POP, the requested content from the origin server; and

returning the requested content from the origin-facing POP to the client-facing POP.

14. A client-facing point of presence (“

POP”

) associated with a content delivery network, the client-facing POP comprising;

a non-transitory data store implementing a cache of content, wherein the content is associated with an origin server that acts as an primary source for the content; and

one or more computing devices in communication with the non-transitory data store, the one or more computing devices configured with computer-executable instructions that, when executed, cause the one or more computing devices to;

receive a request for content that is not included within the cache;

obtain routing information identifying a network distance between the client-facing POP and the origin server and a network distance between the client-facing POP and an origin-facing POP associated with the origin server;

select either the origin-facing POP or the origin server as a content source for the requested content that is not included within the cache of the client-facing POP based at least in part on the network distance between the client-facing POP and the origin server and the network distance between the client-facing POP and the origin-facing POP;

retrieve the requested content from the content source; and

return the requested content in response to the request.

15. The system of claim 14 further comprising a POP manager including one or more computing devices configured with specific computer-executable instructions to:

receive a request from a user associated with the origin server to utilize a secondary POP on the content delivery network; and

select the origin-facing POP as the secondary POP based at least in part on a network distance between the origin-facing POP and the origin server.

16. The system of claim 15, wherein the network distance between the origin-facing POP and the origin server is estimated based at least in part on a geographic distance between the origin-facing POP and the origin server.

17. The system of claim 16, wherein the geographic distance between the origin-facing POP and the origin server is determined based at least in part on network address geolocation techniques.

18. The system of claim 15, wherein the network distance between the origin-facing POP and the origin server is estimated based at least in part on monitoring between communications between the origin-facing POP and at least one of the origin server or an additional computing device associated with the origin server.

19. The system of claim 14, wherein the obtained routing information comprises a first set of routing information identifying the network distance between the client-facing POP and the origin server and a second set of routing information identifying the network distance between the client-facing POP and the origin-facing POP.

20. The system of claim 19, wherein the computer-executable instructions cause the one or more computing devices to select either the origin-facing POP or the origin server as the content source for the requested content at least partly by combining the first and second sets of routing information.