Data differencing across peers in an overlay network

Patent metadata

Field	Value
Publication number	US-2016205221-A1
Application number	US-201514827341-A
Country	US
Kind code	A1
Filing date	Aug 17, 2015
Priority date	Dec 23, 2011
Publication date	Jul 14, 2016
Grant date	—

Abstract

A data differencing technique enables a response from a server to the request of a client to be composed of data differences from previous versions of the requested resource. To this end, data differencing-aware processes are positioned, one at or near the origin server (on the sending side) and the other at the edge closest to the end user (on the receiving side), and these processes maintain object dictionaries. The data differencing-aware processes each execute a compression and differencing engine. Whenever requested objects flow through the sending end, the engine replaces the object data with pointers into the object dictionary. On the receiving end of the connection, when the data arrives, the engine reassembles the data using the same object dictionary. The approach is used for version changes within a same host/path, using the data differencing-aware processes to compress data being sent from the sending peer to the receiving peer.

First claim

What is claimed is as follows:

1 . A method to perform data differencing between a receiving peer entity and a sending peer entity of an overlay network using a dictionary comprising, for a piece of content associated with a host/path, one or more versions of the piece of content and, for each version, a fingerprint, comprising:
receiving a request for a new version of the piece of content and, in response, associating with the request one or more fingerprints corresponding to the one or more versions of the piece of content in the dictionary to generate a modified request that includes the one or more fingerprints; receiving a data stream in response to the modified request, the data stream including data representing a difference between the new version of the piece of content and that version of the piece of content represented by a given one of the one or more fingerprints that was included in the modified request, the data stream also including an identification of the given one of the one or more fingerprints; and responsive to receiving the data stream, generating the new version of the piece of content from the difference and the version of the piece of content represented by the given one of the fingerprints.

2 . The method as described in claim 1 further including generating in the dictionary a new fingerprint corresponding to the new version of the piece of content so generated.

3 . The method as described in claim 1 wherein the data differencing is performed when the piece of content has a given content encoding.

4 . The method as described in claim 1 wherein the data differencing is enabled for any piece of content that is other than in a compressed format.

5 . The method as described in claim 1 wherein the one or more fingerprints corresponding to the one or more versions of the piece of content in the dictionary are associated with the request in an HTTP header.

6 . The method as described in claim 1 wherein a fingerprint is generated by hashing a version of the piece of content.

7 . A method to perform data differencing between a sending peer entity and a receiving peer entity of an overlay network using a dictionary comprising, for a piece of content associated with a host/path, one or more versions of the piece of content and, for each version, a fingerprint, comprising:
receiving a request for a new version of the piece of content, the request having been modified to include one or more fingerprints corresponding to the one or more versions of the piece of content that are then available at the receiving peer entity and, in response, selecting a given one of the one or more fingerprints and providing an instruction to obtain from an origin server the new version of the piece of content; and receiving the new version of the piece of content provided by the origin server and, in response, generating data representing a difference between the new version of the piece of content and that version of the piece of content represented by the given one of the one or more fingerprints; returning, for delivery to the receiving peer entity, a data stream including the differenced data and an identification of the given one of the one or more fingerprints.

8 . The method as described in claim 7 wherein the method further includes generating and storing in the dictionary a new fingerprint corresponding to the new version of the piece of content provided by the origin server.

9 . The method as described in claim 7 wherein the data differencing is performed when the piece of content has a given content encoding.

10 . The method as described in claim 7 wherein the data differencing is enabled for any piece of content that is other than in a compressed format.

11 . The method as described in claim 7 wherein the one or more fingerprints corresponding to the one or more versions of the piece of content are associated with the request in an HTTP header.

12 . The method as described in claim 7 wherein a fingerprint is generated by hashing a version of the piece of content.

Assignees

• Akamai Tech Inc

Inventors

• Gero Charles E

Classifications

• H04L67/565 Primary

  Conversion or adaptation of application format or content (adding application control or application functional data H04L67/561) · CPC title

• H04L67/02

  based on web technology, e.g. hypertext transfer protocol [HTTP] · CPC title

• H04L69/04

  Protocols for data compression, e.g. ROHC · CPC title

• H04L45/7453

  using hashing · CPC title

• H04L69/08 Primary

  Protocols for interworking; Protocol conversion · CPC title