Delivering resources to clients in a distributed computing environment

• US 20070233846A1
• Filed: 05/30/2007
• Published: 10/04/2007
• Est. Priority Date: 02/10/1998
• Status: Active Grant

• Current Assignee: Savvis Communications Corporation (Cyxtera Technologies, Inc.)
• Original Assignee: Level 3 Communications LLC (Lumen Technologies, Inc.)
• Inventors: Farber, David, Swart, Andrew, Greer, Richard, Balter, James
• Granted Patent: US 8,468,245 B2
• Time in Patent Office: Days
• US Class Current: 709/223
• CPC Class Codes: G06F 16/957 Browsing optimisation, e.g. caching or content distillation
• CPC Class Codes: G06F 2209/509 Offload
• CPC Class Codes: G06F 9/505 considering the load
• CPC Class Codes: H04L 43/065 related to network devices
• CPC Class Codes: H04L 43/0817 by checking functioning
• CPC Class Codes: H04L 43/16 Threshold monitoring
• CPC Class Codes: H04L 61/30 Managing network names, e.g. use of aliases or nicknames name-to-address mapping H04L61/45
• CPC Class Codes: H04L 61/301 Name conversion
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/10015 Access to distributed or replicated servers, e.g. using brokers
• CPC Class Codes: H04L 67/1006 with static server selection, e.g. the same server being selected for a specific client
• CPC Class Codes: H04L 67/1008 based on parameters of servers, e.g. available memory or workload monitoring of computer activity G06F11/30
• CPC Class Codes: H04L 67/101 based on network conditions
• CPC Class Codes: H04L 67/1012 based on compliance of requirements or conditions with available server resources
• CPC Class Codes: H04L 67/1014 based on the content of a request
• CPC Class Codes: H04L 67/1019 Random or heuristic server selection
• CPC Class Codes: H04L 67/1021 based on client or server locations
• CPC Class Codes: H04L 67/1023 based on a hash applied to IP addresses or costs
• CPC Class Codes: H04L 67/1025 : Dynamic adaptation of the criteria on which the server selection is based
• CPC Class Codes: H04L 67/1036 : Load balancing of requests to servers for services different from user content provisioning, e.g. load balancing across domain name servers
• 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 67/125 : involving control of end-device applications over a network
• CPC Class Codes: H04L 67/2895 : Intermediate processing functionally located close to the data provider application, e.g. reverse proxies
• CPC Class Codes: H04L 67/56 : Provisioning of proxy services store-and-forward switching systems in data switching networks H04L12/54
• CPC Class Codes: H04L 67/561 : Adding application-functional data or data for application control, e.g. adding metadata
• CPC Class Codes: H04L 67/563 : Data redirection of data network streams
• CPC Class Codes: H04L 67/564 : Enhancement of application control based on intercepted application data
• CPC Class Codes: H04L 67/568 : Storing data temporarily at an intermediate stage, e.g. caching
• CPC Class Codes: H04L 67/5682 : Policies or rules for updating, deleting or replacing the stored data
• CPC Class Codes: H04L 67/61 : taking into account QoS or priority requirements
• CPC Class Codes: H04L 9/40 : Network security protocols

Abstract

A method for delivering resources to clients in a distributed computing environment. At least a first resource associated with a first content provider and maintained on an origin server references a second resource. The second resource is associated with a network formed by a plurality of repeater servers operable to serve the second resource to clients on behalf of the first content provider, the origin server being distinct from the plurality of repeater servers. Responsive to a request that causes the first resource to be served to a client from the origin server, at least one of the plurality of repeater servers is selected to serve the second resource to the client. If a copy of the second resource is available on the selected repeater server, the copy of the second resource is served to the client from the selected repeater server; otherwise, if a copy of the second resource is not available on the selected repeater server, the second resource is replicated on the selected repeater server.

Claims

1. A method for delivering resources to clients in a distributed computing environment, wherein at least a first resource associated with a first content provider and maintained on an origin server references a second resource, the method comprising:

associating the second resource with a network formed by a plurality of repeater servers operable to serve the second resource to clients on behalf of the first content provider, the origin server being distinct from the plurality of repeater servers; and

responsive to a request that causes the first resource to be served to a client from the origin server, selecting at least one of the plurality of repeater servers to serve the second resource to the client; and

responsive to the selected content server being requested to serve the second resource;

checking to determine whether a copy of the second resource is available on the selected repeater server;

if a copy of the second resource is available on the selected repeater server, serving the copy of the second resource to the client from the selected repeater server;

otherwise,

if a copy of the second resource is not available on the selected repeater server, replicating the second resource on the selected repeater server.

2. A method as recited in claim 1, wherein the replicating step comprises:

retrieving a copy of the second resource from peer repeater server in the network.

3. A method as recited in claim 1, wherein the replicating step comprises:

retrieving a copy of the second resource from the origin server.

4. A method as recited in claim 1, wherein the second resource is originally identified as residing on the origin server using a first uniform resource locator (URL) that comprises a first domain name, the associating step comprising:

associating the second resource with at least some of the plurality of repeater servers via a second URL, wherein the second URL is at least partially distinct from the first URL and wherein the plurality of repeater servers associated with the second resource via the second URL comprises the selected repeater server.

5. A method as recited in claim 4, wherein the associating step further comprises:

forming the second URL by prepending data to the first domain name.

6. A method as recited in claim 5, wherein the first resource references the second resource at least by way of a textual reference embedded in the first resource, the method further comprising:

modifying the textual reference to comprise the second URL.

7. A method as recited in claim 6, wherein the modifying step is performed in response to initiation of the request that causes the first resource to be served to the client from the origin server.

8. A method as recited in claim 7, wherein further responsive to the request that causes the first resource to be served to the client from the origin server, the method further comprising:

transmitting to the client an HTTP REDIRECT command comprising the modified textual reference.

9. A method as recited in claim 6, wherein the modifying step is performed prior to initiation of the request that causes the first resource to be served to the client from the origin server.

10. A method as recited in claim 1, wherein the selecting step is performed at least in part by a software component co-located with the origin server.

11. A method as recited in claim 1, wherein the first resource is a web page.

12. A method as recited in claim 1, wherein further responsive to the request that causes the first resource to be served to a client from the origin server, causing the client to be provided an address of the selected repeater server.

13. A method as recited in claim 1, wherein the network comprises additional repeater servers distinct from the plurality of repeater servers, wherein the origin server is further distinct from the additional repeater servers.

14. A method as recited in claim 1, wherein the second resource is originally identified as residing on the origin server using a first uniform resource locator (URL) that comprises a first domain name, the method further comprising:

assigning the second resource a second URL identifying at least the selected repeater server, wherein the second URL is at least partially distinct from the first URL.

15. A method as recited in claim 14, wherein the first resource references the second resource at least by way of a textual reference embedded in the first resource, the assigning step further comprising:

forming the second URL by prepending data identifying the selected repeater server to the first domain name, and wherein the method further comprises;

modifying the textual reference to comprise the second URL.

16. A method for delivering resources to clients from a network of resource servers on behalf of resource providers, wherein at least a first resource maintained on an origin server references a second resource, the origin server being distinct from the network of resource servers, the method comprising associating the second resource with a network of resource servers;

responsive to a request that causes the first resource to be served to a client from the origin server, selecting at least one resource server in the network from which to serve the second resource to the client;

responsive to the selected resource server being requested to serve the second resource;

checking to determine whether a copy of the second resource is available on the selected resource server;

if a copy of the second resource is available on the-selected resource server, serving the copy of the second resource to the client from the selected resource server;

otherwise,

if a copy of the second resource is not available on the selected resource server, replicating the second resource on the selected repeater server.

17. A method as recited in claim 16, wherein the replicating step comprises:

retrieving a copy of the second resource from the origin server.

18. A method as recited in claim 16, wherein the second resource is originally identified as residing on the origin server using a first uniform resource locator (URL) that comprises a first domain name, the associating step comprising:

associating the second resource with at least some of the plurality of resource servers via a second URL, wherein the second URL is at least partially distinct from the first URL and wherein the plurality of repeater servers associated with the second resource via the second URL comprises the selected resource server.

19. A method as recited in claim 18, wherein the associating step further comprises:

forming the second URL by prepending data to the first domain name.

20. A method for delivering resources to clients in a distributed computing environment, wherein at least a first resource associated with a first content provider and maintained on an origin server references a second resource, the method comprising:

associating the second resource with a network formed by a plurality of repeater servers operable to serve the second resource to clients on behalf of the first content provider, the origin server being distinct from the plurality of repeater servers; and

responsive to a request that causes the first resource to be served to a client from the origin server;

selecting a repeater server in the network from which to serve the second resource to the client; and

causing the client to be provided an address of the selected repeater server;

responsive to the selected repeater server being requested to serve the second resource;

checking to determine whether a copy of the second resource is available on the selected repeater server;

if a copy of the second resource is available on the selected repeater server, serving the copy of the second resource to the client from the selected repeater server;

otherwise,

if a copy of the second resource is not available on the selected repeater server, replicating the second resource on the selected repeater server.

21. A method as defined in claim 20, wherein the selecting step is performed at least in part by a software component co-located with the origin server.

22. A method as recited in claim 20, wherein the second resource is originally identified as residing on the origin server using a first uniform resource locator (URL) that comprises a first domain name, the method further comprising:

assigning the second resource a second URL identifying at least the selected repeater server, wherein the second URL is at least partially distinct from the first URL.

23. A method as recited in claim 22, wherein the assigning step further comprises:

forming the second URL by prepending data identifying the selected repeater server to the first domain name.

24. A method as recited in claim 23, wherein the first resource references the second resource at least by way of a textual reference embedded in the first resource, the method further comprising:

modifying the textual reference to comprise the second URL.

25. A method as recited in claim 24, wherein the modifying step is performed in response to initiation of the request that causes the first resource to be served to the client from the origin server.

26. An Internet content delivery method for delivering resources from multiple content providers to multiple clients via a network of repeater servers, said resources including web pages associated with said content providers, at least some of said web pages including references to other resources, and wherein a first web page associated with a first content provider includes a reference to a first resource also associated with said first content provider, the method comprising:

after said first web page has been served to a requesting client from an origin server associated with said first content provider, serving the first resource to the requesting client from a particular repeater server in the network of repeater servers by;

(A) if a copy of the first resource is not cached locally at the particular repeater server, said particular repeater server attempting to obtain a copy of said first resource from a peer repeater server or from an origin server associated with said first content provider; and

then serving the copy of the first resource from the particular repeater server to the requesting client;

otherwise,

(B) if a copy of the first resource is cached locally at said particular repeater server, serving the copy of the first resource from the particular server to the requesting client.

27. An Internet method as in claim 26, wherein said web page is identified by a first Uniform Resource Locator (URL) having a first domain name that resolves to said origin server associated with said first content provider and wherein said first resource is identified in said web page by a second URL having a second domain name that resolves to said network of repeater servers.

28. An Internet method as in claim 27, wherein said first domain name and said second domain name are fully qualified domain names.

29. An Internet method as in claim 28, wherein said second domain name identifies said particular repeater server.

30. An Internet method as in claim 27 wherein said second URL includes said second domain name prepended to said first domain name.