Methods and systems for caching content valid for a range of client requests

• US 10,547,703 B2
• Filed: 07/22/2018
• Issued: 01/28/2020
• Est. Priority Date: 10/04/2013
• Status: Active Grant

• Current Assignee: Akamai Technologies, Inc.
• Original Assignee: Akamai Technologies, Inc.
• Inventors: Flack, Martin T., Steiner, Moritz M., Ludin, Stephen L., Hatala, Jozef
• Primary Examiner(s): Tiv, Backhean
• Application Number:
  US16/041,793
• Publication Number:
  US 20190058775A1
• Time in Patent Office: 555 Days
• Field of Search: None
• CPC Class Codes: H04L 2209/76 Proxy, i.e. using intermediary entity to perform cryptographic operations network architectures or network communication protocols using hop-by-hop encryption H04L63/0464
• CPC Class Codes: H04L 63/0884 by delegation of authentication, e.g. a proxy authenticates an entity to be authenticated on behalf of this entity vis-à-vis an authentication entity
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching
• CPC Class Codes: H04N 21/23106 involving caching operations prefetching while addressing of a memory level in which the access to the desired data or data block requires associative addressing means within memory systems or architectures G06F12/0862; caching at an intermediate stage in a data network H04L67/568

Abstract

Described herein are systems, devices, and methods for content delivery on the Internet. In certain non-limiting embodiments, a caching model is provided that can support caching for indefinite time periods, potentially with infinite or relatively long time-to-live values, yet provide prompt updates when the underlying origin content changes. In one approach, an origin server can annotate its responses to content requests with tokens, e.g., placing them in an appended HTTP header or otherwise. The tokens can drive the process of caching, and can be used as handles for later invalidating the responses within caching proxy servers delivering the content. Tokens may be used to represent a variety of kinds of dependencies expressed in the response, including without limitation data, data ranges, or logic that was a basis for the construction of the response.

Claims

1. A computer-implemented method performed by a content delivery network (CDN) server that has circuitry forming one or more processors and memory holding instructions for execution by the one or more processors, the method comprising:

sending a request to an origin server;

receiving a response to the request from the origin server, the response comprising;

(i) content that is responsive to the request and (ii) a range token, the range token specifying a data range;

serving the content to a first client device;

storing the content in a cache local to the CDN server, in association with the range token;

serving the content from the cache to at least a second client device, in response to a request from the second client device;

receiving a message from the origin server, the message comprising an invalidation assertion that comprises any of;

(iii) a specific data point within the data range and (iv) a sub-range within the data range;

upon receipt of the message, the CDN server determining that any of (iii) the specific data point and the (iv) sub-range falls within the data range specified by the range token;

in response to the determination, invalidating the content that was stored in the cache local to the CDN server, such that the CDN server no longer serves the content to client devices from the cache.

2. The method of claim 1, wherein the message is received from the origin server via another CDN server.

3. The method of claim 1, wherein, prior to sending the request to the origin server, the CDN server receives a request from the first client device that specifies the data range as being of interest to the end user of the first client device.

4. The method of claim 3, where the first client request comprises a request for service from an application programmer interface (API).

5. The method of claim 1, wherein the CDN server provides an application programmer interface (API) service, and the CDN server serves the content to the first client device and to the second client device as part of the API service.

6. The method of claim 1, wherein the data range comprises one or more of:

(a) a starting latitude and an ending latitude, and

(b) a starting longitude and an ending longitude.

7. The method of claim 1, wherein the data range represents data for a particular time period.

8. The method of claim 1, wherein the origin server generates the message in response to an event occurring at the origin server that changes data within the data range.

9. The method of claim 1, wherein:

the invalidation assertion comprises (iii) a specific data point within the data range; and

upon receipt of the message, the CDN server determines that (iii) the specific data point falls within the data range specified by the range token.

10. The method of claim 1, wherein:

the invalidation assertion comprises (iv) a sub-range within the data range;

upon receipt of the message, the CDN server determines that (iv) the sub-range falls within the data range specified by the range token.

11. The method of claim 1, wherein the invalidation assertion comprises an implicit invalidation assertion.

12. A system, comprising:

A. a content delivery network (CDN) server that has circuitry forming one or more processors and memory holding instructions that upon execution by the one or more processors to cause the CDN server to;

send a request to an origin server;

receive a response to the request from the origin server, the response comprising;

(i) content that is responsive to the request and (ii) a range token, the range token specifying a data range;

serve the content to a first client device;

store the content in a cache local to the CDN server, in association with the range token;

serve the content from the cache to at least a second client device, in response to a request from the second client device;

B. the origin server having circuitry forming one or more processors and memory holding instructions that upon execution by the one or more processors to cause the origin server to;

receive any of an addition and modification to data at the origin server;

determine that the any of addition and modification changes data within the data range;

in response to said determination, generate a message comprising an invalidation assertion that comprises any of;

(iii) a specific data point within the data range and (iv) a sub-range within the data range;

send the message to the CDN server;

C. the CDN server memory holding instructions that upon execution by the one or more processors to cause the CDN server to;

receive the message from the origin server;

upon receipt of the message, determine that any of (iii) the specific data point and the (iv) sub-range falls within the data range specified by the range token;

in response to the determination, invalidate the content that was stored in the cache local to the CDN server, such that the CDN server no longer serves the content to client devices from the cache.

13. The system of claim 12, wherein, prior to sending the request to the origin server, the CDN server receives a request from the first client device that specifies the data range as being of interest to the end user of the first client device.

14. The system of claim 12, where the first client request comprises a request for service from an application programmer interface (API).

15. The system of claim 12, the CDN server memory holding instructions that upon execution by the one or more processors to cause the CDN server to:

provide an application programmer interface (API) service, and the CDN server serves the content to the first client device and to the second client device as part of the API service.

16. The system of claim 12, wherein the data range comprises one or more of:

(a) a starting latitude and an ending latitude,

and

(b) a starting longitude and an ending longitude.

17. The system of claim 12, wherein the data range represents data for a particular time period.

18. The system of claim 12, wherein:

the invalidation assertion comprises (iii) a specific data point within the data range; and

upon receipt of the message, the CDN server determines that (iii) the specific data point falls within the data range specified by the range token.

19. The system of claim 12, wherein:

the invalidation assertion comprises (iv) a sub-range within the data range;

upon receipt of the message, the CDN server determines that (iv) the sub-range falls within the data range specified by the range token.

20. The system of claim 12, wherein the invalidation assertion comprises an implicit invalidation assertion.

21. A computer-implemented method performed by a content delivery network (CDN) server that has circuitry forming one or more processors and memory holding instructions for execution by the one or more processors, the method comprising:

sending a request to an origin server;

receiving a response to the request from the origin server, the response comprising;

(i) content that is responsive to the request and (ii) a range token, the range token specifying a first data range, and (iii) a tolerance value for the first data range endpoints;

serving the content to a first client device;

storing the content in a cache local to the CDN server, in association with the range token;

receiving a request from a second client device, the request specifying a second data range that describes the content of interest to a user of the second client device;

in response to the request from the second client device, determining whether the content stored in the cache is a cache hit, at least by;

applying the tolerance value to the first data range endpoints;

determining that the second data range falls within the first data range given the tolerance value for the endpoints;

determining that the range token has not been invalidated by the origin server;

upon a determination that the content stored in the cache is a cache hit, serving the content from the cache to the second client device, in response to the request from the second client device.

22. The method of claim 21, wherein the first data range and second data range each correspond to a geographic area.

23. The method of claim 21, wherein the data range comprises one or more of:

(a) a starting latitude and an ending latitude, and

(b) a starting longitude and an ending longitude.

24. The method of claim 21, wherein second data range is specified in one or more URL parameters.

25. The method of claim 21, wherein, prior to sending the request to the origin server, the CDN server receives a request from the first client device that specifies the first data range as being of interest to the end user of the first client device.

26. The method of claim 21, wherein the CDN server provides an application programmer interface (API) service, and the CDN server serves the content to the first client device and to the second client device as part of the API service.