Method and system for tiered distribution in a content delivery network

• US 20030233423A1
• Filed: 04/09/2002
• Published: 12/18/2003
• Est. Priority Date: 04/09/2002
• Status: Active Grant

• Current Assignee: Akamai Technologies, Inc.
• Original Assignee: Akamai Technologies, Inc.
• Inventors: Berkheimer, Andrew D., Dilley, John A.
• Granted Patent: US 7,133,905 B2
• Time in Patent Office: Days
• US Class Current: 709/214
• CPC Class Codes: H04L 65/612 for unicast
• CPC Class Codes: H04L 67/2885 Hierarchically arranged intermediate devices, e.g. for hierarchical caching
• CPC Class Codes: H04L 67/52 specially adapted for the location of the user terminal
• CPC Class Codes: H04L 67/564 Enhancement of application control based on intercepted application data
• CPC Class Codes: H04L 67/5651 Reducing the amount or size of exchanged application data
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04W 4/02 Services making use of location information

Abstract

A tiered distribution service is provided in a content delivery network (CDN) having a set of surrogate origin (namely, “edge”) servers organized into regions and that provide content delivery on behalf of participating content providers, wherein a given content provider operates an origin server. According to the invention, a cache hierarchy is established in the CDN comprising a given edge server region and either (a) a single parent region, or (b) a subset of the edge server regions. In response to a determination that a given object request cannot be serviced in the given edge region, instead of contacting the origin server, the request is provided to either the single parent region or to a given one of the subset of edge server regions for handling, preferably as a function of metadata associated with the given object request. The given object request is then serviced, if possible, by a given CDN server in either the single parent region or the given subset region. The original request is only forwarded on to the origin server if the request cannot be serviced by an intermediate node.

Claims

1. A method operative in a content delivery network (CDN) having a set of surrogate origin servers organized into regions and that provide content delivery on behalf of participating content providers, wherein a given content provider operates an origin server, comprising:

establishing a cache hierarchy in the CDN comprising a given surrogate origin server region and either (a) a single parent region located in a given location, or (b) a subset of parent regions located in given core Internet locations;

in response to a determination that a given object request cannot be serviced in the given surrogate origin server region, directing the given object request to the single parent region or to a given one of the subset of parent regions, based on metadata associated with the given object request, instead of to an origin server; and

attempting to service the given object request from a given server in the single parent region or the given one of the subset of parent regions.

2. The method as described in claim 1 further including the step of:

if the given object request cannot be serviced from the given server, forwarding the given object request back to the origin server.

3. The method as described in claim 1 wherein the metadata associated with the given object request indicates that the given object is a candidate for delivery via the cache hierarchy.

4. The method as described in claim 1 wherein the metadata is identified by a given entity and further including the step of delivering the metadata to the given surrogate origin server region.

5. The method as described in claim 4 wherein the single parent region is associated with a given content provider.

6. The method as described in claim 5 wherein the single parent region is co-located with the origin server of the given content provider.

7. The method as described in claim 1 further including the step of attempting to service the given object request from a peer in the given surrogate origin server region prior to directing the request to the single parent region or to a given one of the subset of parent regions.

8. The method as described in claim 1 wherein a first participating content provider uses the single parent region and a second participating content provider uses a subset of the parent regions.

9. The method as described in claim 1 further including the steps of:

if a given object request cannot be serviced in the given surrogate origin server region, rewriting a first data string associated with the given object request into a second data string that points to the cache hierarchy; and

resolving the second data string to identify a best core region and an optimal server in the best core region to service the given object request.

10. In a content delivery network having a set of surrogate origin servers organized into regions and that provide content delivery on behalf of participating content providers, wherein a given content provider operates an origin server, the improvement comprising:

establishing a cache hierarchy in the CDN comprising a given surrogate origin server region and either (a) a single parent region or (b) a subset of the parent server regions;

in response to a determination that a given object request cannot be serviced in the given surrogate origin server region, attempting to service the request from a peer in the given surrogate origin server region;

if the request cannot be serviced from a peer in the given surrogate origin server region, providing the given object request to the single parent region or to a given one of the subset of parent regions, based on metadata associated with the given object request, instead of to an origin server; and

attempting to service the given object request in a server in the single parent region or the given one of the subset of parent regions.

11. A server connectable in a content delivery network having a set of servers organized into regions that provide content delivery on behalf of participating content providers, wherein the content delivery network includes given nodes intermediate the server and a given content provider origin server, comprising:

code executable in the server for determining whether a given object request can be serviced;

code executable in the server and responsive to a determination that the given object request cannot be serviced for evaluating object metadata to determine whether the given object request is to be serviced by an intermediate node;

code executable in the server and responsive to a determination that the given object request is to be serviced by an intermediate node for generating a data string that is resolvable to identify a given node intermediate the server and the given content provider origin server; and

code executable in the server and responsive to resolution of the data string to identify a given intermediate node to which the given object request is then directed for handling.