Method and apparatus for selecting cache and proxy policy

• US 7,912,921 B2
• Filed: 11/22/2005
• Issued: 03/22/2011
• Est. Priority Date: 06/26/2001
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Van Antwerp, Mark D., Dean, Dawson F., Wang, Chih-Kan, Knowlton, Chadd B., Roth, David J., O'Rourke, Bret P.
• Primary Examiner(s): Donaghue; Larry
• Application Number:
  US11/285,048
• Publication Number:
  US 20060095532A1
• Time in Patent Office: 1,946 Days
• Field of Search: 709/219
• US Class Current: 709/219
• CPC Class Codes: H04L 67/5682 Policies or rules for updating, deleting or replacing the stored data
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A cache server includes a media serving engine that is capable of distributing media content. A cache engine is coupled to the media serving engine and capable of caching media content. A set of cache policies is accessible by the cache engine to define the operation of the cache engine. The cache server can be configured to operate as either a cache server or an origin server. The cache server also includes a data communication interface coupled to the cache engine and the media serving engine to allow the cache engine to receive media content across a network and to allow the media serving engine to distribute media content across the network. The cache policies include policies for distributing media content from the media server, policies for handling cache misses, and policies for prefetching media content.

Claims

1. A server, comprising:

a media serving engine to distribute media content;

a cache engine coupled to the media serving engine, the cache engine to cache the media content;

a storage device to store a plurality of server policies, each server policy defining operating characteristics of the server, with one of the plurality of server policies being a currently active server policy, the plurality of server policies comprising a first server policy determining the server is to operate as a cache server and further comprising a second server policy, defined by a system administrator, determining the server is to operate as an origin server, the plurality of server policies comprising;

prefetching policies for causing the cache server to identify a media content, determine a particular time period during which the media content should be downloaded, and download the media content from the origin server without yet receiving a request for the media content; and

frequency policies such that for each time the request is made for the media content, the frequency policies cause the cache server to determine a version of the media content and whether the version of the media content is acceptable or a new version of the media content is to be downloaded from the origin server;

a processor coupled to the storage device, the processor to control operation of the server based on the currently active server policy and the second server policy,

wherein the media serving engine distributes the media content to a plurality of client devices while concurrently ignoring the first cache policy to operate as the cache server and implementing the second cache policy to operate as the origin server, the origin server being a source of the media content.

2. A server as recited in claim 1, further comprising a data communication interface coupled to the storage device and the processor, wherein the data communication interface is to transmit instructions to the server to change the currently active server policy.

3. A server as recited in claim 1, wherein each of the plurality of server policies defines a manner in which the server handles media content received from at least one media content source.

4. A server as recited in claim 1, wherein each of the plurality of server policies defines a manner in which the server distributes media content to a plurality of clients.

5. A server as recited in claim 1, wherein the server policies include policies for caching media content.

6. An apparatus, comprising:

a storage device to store a first cache policy and a second cache policy, wherein the first cache policy causes the apparatus to operate as a cache server and the second cache policy causes the apparatus to operate as an origin server, and wherein the first cache policy or the second cache policy is a currently active cache policy;

a media serving engine to distribute media content to a plurality of client devices while concurrently ignoring the first cache policy to operate as the cache server and implementing the second cache policy to operate as the origin server, the origin server being a source of the media content;

a cache engine coupled to the media serving engine and the storage device, the cache engine to process media based on the currently active cache policy,

wherein the first and second cache policies include;

policies for handling cache misses when the cache server does not contain content requested by a client, the policies for handling cache misses are further to determine whether a copy of the requested content should be cached by the cache server to satisfy future requests for the previously requested content;

policies for, when the copy of the requested content is cached by the cache server, determining whether existing cached content should be deleted to release storage space on the cache server;

policies for, when a determination is made that existing cached content should be deleted, determining a least frequently requested content of the existing cached content to be deleted;

policies for prefetching media content not yet requested by the client, wherein the policies for prefetching media content cause the cache server to identify media content, determine a particular time period during which the media content should be downloaded, and download the media content from the origin server prior to receiving a request from the client; and

frequency policies such that for each time the request is made for the media content, determining a version of the media content and whether the version of the media content is acceptable or a new version of the media content is to be downloaded from the origin server.

7. An apparatus as recited in claim 6, wherein the policies for handling cache misses determine how to deliver the requested content to the client by performing one of:

cause the cache server to download a copy of the requested content while the client waits for the requested content;

redirect the client to a different cache server to retrieve the requested content; and

redirect the client to the origin server to retrieve the requested content.

8. An apparatus as recited in claim 6, wherein the cache engine is to cache media content from a plurality of media content sources based on the currently active cache policy.

9. An apparatus as recited in claim 6, further comprising a data communication interface coupled to the cache engine and the media serving engine, wherein the data communication interface is to transmit instructions to the server to change the currently active cache policy.

10. An apparatus as recited in claim 6, further comprising a data communication interface coupled to the cache engine and the media serving engine to allow the cache engine to retrieve media content via a network.

11. An apparatus as recited in claim 6, further including a data communication interface coupled to the cache engine and the media serving engine to allow the media serving engine to distribute media content across a network.

12. An apparatus as recited in claim 6, wherein each of the cache policies defines a manner in which media content is distributed to a plurality of clients.

13. A method, comprising:

configuring a server based on a cache server policy, the cache server policy causing the server to operate as a cache server for a first plurality of client devices;

operating the server according to operating characteristics of the cache server policy,

the cache server policy causing the server to identify a media content, determine a particular time period during which the media content should be downloaded, and download the media content from another server,

the cache server policy further causing the server to, for each time the request is made for the media content, determine a version of the media content and whether the version of the media content is acceptable or a new version of the media content is to be downloaded from the origin server;

receiving a request for additional media content stored on the server from a second plurality of client devices differing from the first plurality of client devices; and

providing the additional media content to the second plurality of client devices while concurrently ignoring the cache server policy such that the server operates as an origin server, the origin server being a source of the additional media content.

14. A method as recited in claim 13, further comprising:

receiving a third server policy to define a set of operating characteristics for the server; and

establishing the third server policy as the currently active server policy, wherein the server is to function according to the operating characteristics of the third server policy.

15. A method as recited in claim 13, wherein the new server policy further defines a manner in which the server handles media content received from a plurality of media content sources.