Partial object caching

• US 8,370,452 B2
• Filed: 02/10/2011
• Issued: 02/05/2013
• Est. Priority Date: 12/27/2010
• Status: Active Grant

• Current Assignee: Limelight Networks, Inc.
• Original Assignee: Limelight Networks, Inc.
• Inventors: Harvell, Bradley B., Kokal, Mohan I., Eggleston, Jason
• Primary Examiner(s): TAYLOR, NICHOLAS R
• Application Number:
  US13/024,824
• Publication Number:
  US 20120166574A1
• Time in Patent Office: 726 Days
• Field of Search: 709/217, 709/203, 709/231, 709/229
• US Class Current: 709/217
• CPC Class Codes: G06F 15/167 using a common memory, e.g. mailbox
• CPC Class Codes: G06F 16/9574 of access to content, e.g. by caching

Abstract

Techniques for partial object caching are disclosed. For example, a method includes receiving, at a content delivery network (CDN) from a end user device, a request for at least a portion of an object, retrieving the portion of the object from a content site and delivering the portion of the object to the end user device, and caching, in a partial object cache, the portion of the object. Further, the method may include receiving a subsequent request for the portion of the object, and retrieving, from the partial object cache the portion of the object and delivering the portion of the object in response to the subsequent request.

Claims

1. A method of implementing partial object caching, the method comprising:

receiving, at a content delivery network (CDN) from an end user device, a current request for at least an arbitrarily-sized portion of an object;

retrieving the arbitrarily-sized portion of the object from a content site and delivering the arbitrarily-sized portion of the object to the end user device;

caching, in a partial object cache, the arbitrarily-sized portion of the object;

receiving a subsequent request for the arbitrarily-sized portion of the object;

retrieving, from the partial object cache the arbitrarily-sized portion of the object and delivering the arbitrarily-sized portion of the object in response to the subsequent request, and

in a response to a new request for a second portion of the object that is not covered by the cached arbitrarily-sized portion of the object, modifying the new request, in flight, to stop at the byte just prior to the cached arbitrarily-sized portion.

2. The method of implementing partial object caching as in claim 1, further comprising determining that there is currently a fragment being created that covers the same contiguous un-cached portion of the object.

3. The method of implementing partial object caching as in claim 1, determining that the partial object cache does not include data for the current request.

4. The method of implementing partial object caching as in claim 3, in response to determining that the partial object cache does not include data for the current request, requesting the portion from an origin of the object, wherein the origin comprises one or more of:

a neighbor cache or an intermediate cache.

5. The method of implementing partial object caching as in claim 1, further comprising determining that the portion of the object is complete, and in response to determining that the portion of the object is complete, retrieving a subsequent portion of the object.

6. The method of implementing partial object caching as in claim 5, further comprising determining that the subsequent portion of the object is stored in the partial object cache, and delivering the subsequent portion to the end user device form the partial object cache.

7. The method of implementing partial object caching as in claim 1, further comprising determining that the end of the request has been reached, and in response to determining that the end of the request has been reached, completing the delivery of the object.

8. The method of implementing partial object caching as in claim 1, further comprising determining that an error has occurred on the client or at the server.

9. The method of implementing partial object caching as in claim 8, further comprising, in response to determining the error, still caching any delivery portion of the object in the partial object cache.

10. The method of implementing partial object caching as in claim 1, further comprising:

concatenating, transparent to the end user device, multiple portions of the cached object; and

delivering the concatenated multiple portions of the cached object to the end user device.

11. The method of implementing partial object caching as in claim 1, wherein the partial object cache is at an edge server, and wherein the edge server is in communication with the CDN.

12. The method of implementing partial object caching as in claim 11, wherein the partial object cache comprises a cache hierarchy.

13. The method of implementing partial object caching as in claim 12, wherein the cache hierarchy is configured to store any portion of the object at one or more levels of the cache hierarchy.

14. The method of implementing partial object caching as in claim 13, wherein each level of the cache hierarchy moves upstream to the object'"'"'s origin.

15. The method of implementing partial object caching as in claim 1, wherein the partial object cache comprises a byte cache.

16. The method of implementing partial object caching as in claim 1, further comprising:

determining if a number of bytes included in the portion of the object at least exceeds a byte threshold; and

in response to determining that the number of bytes included in the first portion of the object exceeds the byte threshold, caching the first portion of the object in the first cached partial object.

17. A method of implementing partial object caching as in claim 1 wherein:

the object comprises one or more of the following;

an audio object, a data object, a file, or a video object; and

a first portion of the object is encoded with a first bit rate and a second portion of the object is encoded in a second bit rate.

18. A method of implementing partial object caching as in claim 17, further comprising in response to the first portion of the object being encoded with the first bit rate and the second portion of the object being encoded with the second bit rate, caching the first portion of the object in a first partial object and the second portion of the object in the second partial object.

19. A non-transitory computer-readable medium for implementing partial object caching, having sets of instructions stored thereon which, when executed by a computer, cause the computer to:

receive a current request for at least a arbitrarily-sized portion of an object;

retrieve the arbitrarily-sized portion of the object from a content site and delivering the arbitrarily-sized portion of the object to the end user device;

cache, in a partial object cache, the arbitrarily-sized portion of the object;

receive a subsequent request for the arbitrarily-sized portion of the object; and

retrieve, from the partial object cache the arbitrarily-sized portion of the object and delivering the arbitrarily-sized portion of the object in response to the subsequent request, and

in a response to a new request for a second portion of the object that is not covered by the cached arbitrarily-sized portion of the object, modifying the new request, in flight, to stop at the byte just prior to the cached arbitrarily -sized portion.