Domain name resolution resource allocation

• US 8,195,837 B2
• Filed: 03/18/2010
• Issued: 06/05/2012
• Est. Priority Date: 11/21/2005
• Status: Active Grant

• Current Assignee: Limelight Networks, Inc.
• Original Assignee: Limelight Networks, Inc.
• Inventors: McCarthy, Nils H., Harvell, Brad B., Stafford, Lee A., Baldus, Gary S., Gordon, Michael M.
• Primary Examiner(s): Nawaz, Asad M
• Assistant Examiner(s): HENRY, MARIEGEORGES A
• Application Number:
  US12/726,840
• Publication Number:
  US 20100299439A1
• Time in Patent Office: 810 Days
• Field of Search: 709/217, 709/225, 709/245
• US Class Current: 709/245
• CPC Class Codes: G06F 16/9574 of access to content, e.g. by caching
• CPC Class Codes: H04L 45/74 Address processing for routing
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• CPC Class Codes: H04L 61/4552 Lookup mechanisms between a plurality of directories; Synchronisation of directories, e.g. metadirectories
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• 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 67/1012 based on compliance of requirements or conditions with available server resources
• CPC Class Codes: H04L 67/1017 based on a round robin mechanism
• CPC Class Codes: H04L 67/1019 Random or heuristic server selection
• CPC Class Codes: H04L 67/1029 using data related to the state of servers by a load balancer
• CPC Class Codes: H04L 67/1034 Reaction to server failures by a load balancer
• 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 67/568 Storing data temporarily at an intermediate stage, e.g. caching

Abstract

A content delivery network (CDN) for delivering content over the Internet is disclosed in one embodiment. The CDN is configured to deliver content for others and includes a domain resolution service (DNS) server, caching servers and an Internet interface. The DNS server receives a first domain resolution request and produces a first DNS solution, and receives a second domain resolution request and produces a second DNS solution. The first and second domain resolution requests correspond to a same domain. The caching servers correspond to a plurality of addresses. The interface receives domain resolution requests, which include the first and second domain resolution requests, and transmits DNS solutions, which include the first and second DNS solutions. The first DNS solution comprises a first plurality of addresses corresponding to at least a first subset of the plurality of caching servers, and the second DNS solution comprises a second plurality of addresses corresponding to at least a second subset of the plurality of caching servers. The first DNS solution is different from the second DNS solution in that the second subset includes an address for a caching server not in the first subset. The second subset is chosen to generally match a processing power of the first subset.

Claims

1. A content delivery network (CDN) for delivering content over the Internet using a plurality of points of presence (PoPs) that are geographically distributed, wherein the CDN is configured to deliver content for others, the CDN comprising:

a domain resolution service (DNS) server, wherein;

the plurality of PoPs include a first PoP, a second PoP and a third PoP;

the DNS server is located in the first PoP;

the DNS server is configured to receive a first domain resolution request and produces a first DNS solution,

the DNS server is configured to receive a second domain resolution request and produces a second DNS solution,

the DNS server is configured to receive a third domain resolution request and produces a third DNS solution, and

the first second and third domain resolution requests correspond to a same domain;

a plurality of caching servers located within the plurality of PoPs, wherein the plurality of caching servers correspond to a plurality of addresses; and

an interface with the Internet for the first PoP, wherein;

the interface is configured to;

receive a plurality of domain resolution requests, and

transmit a plurality of DNS solutions,

the plurality of DNS solutions comprise the first, second and third DNS solutions,

the plurality of domain resolution requests comprise the first second and third domain resolution requests,

the first DNS solution comprises a first plurality of addresses corresponding to at least a first subset of the plurality of caching servers, wherein the first plurality of addresses includes a first address,

the first DNS solution is provided at a first time,

the second DNS solution comprises a second plurality of addresses corresponding to at least a second subset of the plurality of caching servers,

the second DNS solution is provided at a second time,

the third DNS solution comprises a third plurality of addresses corresponding to at least a third subset of the plurality of caching servers,

the third DNS solution is provided at a third time,

the first DNS solution is different from the second DNS solution in that the first subset includes the first address for a first caching server, wherein the first address is not in the second subset,

the first caching server is no longer allocated for DNS solutions corresponding to the domain after the first time and before the third time,

the first caching server is no longer allocated for DNS solutions corresponding to the domain based, at least in part, on activity associated with the domain relative to a first threshold,

the third DNS solution is different from the second DNS solution in that the third subset includes the first address for the first caching server,

the first caching server is allocated for DNS solutions corresponding to the domain at the third time, and

the first caching server is allocated for DNS solutions corresponding to the domain based, at least in part, on activity associated with the domain relative to a second threshold.

2. The CDN for delivering content over the Internet as recited in claim 1, wherein the first caching server not in the second subset is no longer allocated for DNS solutions corresponding to the domain is based, at least in part, on one or more of:

a content originator and/or content object; and

an associated service level.

3. The CDN for delivering content over the Internet as recited in claim 1, wherein

the second threshold is lower than the first threshold.

4. The CDN for delivering content over the Internet as recited in claim 3, wherein the third subset is the same as the first subset.

5. The CDN for delivering content over the Internet as recited in claim 1, wherein the second subset includes a second caching server not in the first subset to replace the first caching server not in the second subset.

6. The CDN for delivering content over the Internet as recited in claim 5, wherein the second caching server not in the first subset is chosen to generally match a processing power of the first caching server not in the second subset.

7. The CDN for delivering content over the Internet as recited in claim 5, wherein:

the processing power is determined using one or more figures of merit; and

the one or more figures of merit characterize the plurality of caching servers in a subset.

8. The CDN for delivering content over the Internet as recited in claim 1, wherein:

the first and second DNS solutions list common addresses in the first and second subsets in a different order; and

the different order varies in at least one of a mixed-up fashion, a round-robin fashion, or a random fashion.

9. The CDN for delivering content over the Internet as recited in claim 1, further comprising a wide area network coupling the plurality of caching servers together, wherein at least one of the plurality of caching servers is geographically remote from the others in the plurality of caching servers.

10. The CDN for delivering content over the Internet as recited in claim 1, wherein the first caching server not in the second subset is no longer allocated for DNS solutions corresponding to the domain after the first caching server fails a health check.

11. The CDN for delivering content over the Internet as recited in claim 1, wherein the first caching server not in the second subset is no longer allocated for DNS solutions corresponding to the domain after measuring that the first caching server is utilized beyond the first threshold.

12. The CDN for delivering content over the Internet as recited in claim 1, wherein the first caching server not in the second subset is no longer allocated for DNS solutions corresponding to the domain after measuring that resource utilization for the first caching server is has crossed the first threshold.

13. The CDN for delivering content over the Internet as recited in claim 1, wherein the second subset of the plurality of caching servers for the second DNS solution includes a second caching server in the second PoP and a third caching server in the third PoP.

14. The CDN for delivering content over the Internet as recited in claim 1, wherein the second DNS solution includes a second address that resolves to the second PoP and a third address that resolves to the third PoP.

15. The CDN for delivering content over the Internet as recited in claim 1, wherein the second DNS solution includes a second address that resolves to the first PoP and a third address that resolves to the second PoP.

16. The CDN for delivering content over the Internet as recited in claim 1, wherein the first and second thresholds are equal.

17. A method for delivering content over the Internet using a plurality of points of presence (PoPs) that are geographically distributed, wherein the method comprises:

receiving a first domain resolution request with a PoP from the plurality of PoPs;

producing a first DNS solution with the PoP corresponding to the first domain resolution request;

returning the first DNS solution from the PoP;

receiving a second domain resolution request with the PoP;

producing a second DNS solution with the PoP corresponding to the second domain resolution request;

returning the second DNS solution from the PoP;

receiving a third domain resolution request with the PoP;

producing a third DNS solution with the PoP corresponding to the third domain resolution request; and

returning the third DNS solution from the PoP, wherein;

the first, second and third domain resolution requests correspond to a same domain or content originator,

a plurality of caching servers corresponding to a plurality of addresses,

the first DNS solution comprises a first plurality of addresses corresponding to at least a first subset of the plurality of caching servers,

the first DNS solution is produced at a first time,

the second DNS solution comprises a second plurality of addresses corresponding to at least a second subset of the plurality of caching servers,

the second DNS solution is produced at a second time,

the third DNS solution comprises a third plurality of addresses corresponding to at least a third subset of the plurality of caching servers,

the third DNS solution is produced at a third time,

the first subset includes at least one server that is different from the second subset, based, at least in part, on a change in allocation of a first caching server for DNS solutions corresponding to the domain or content originator,

the first caching server is no longer allocated for DNS solutions corresponding to the domain after the first time and before the third time,

the first caching server is removed from allocation for DNS solutions corresponding to the domain based, at least in part, on activity associated with the domain or content originator relative to a first threshold,

the third subset is different from the second subset in that the third subset includes the first caching server,

the first caching server is allocated for DNS solutions corresponding to the domain or content originator at the third time, and

the first caching server is allocated for DNS solutions corresponding to the domain or content originator, based, at least in part, on activity associated with the domain relative to a second threshold.

18. The method for delivering content over the Internet, as recited in claim 17, wherein the change in allocation of the first server for DNS solutions is based, at least in part, on one or more of:

a content originator and/or content object; and

an associated service level.

19. The method for delivering content over the Internet, as recited in claim 17, wherein the second subset includes a replacement server chosen to replace the first server of the first subset that is not in the second subset.

20. The method for delivering content over the Internet, as recited in claim 19, wherein the replacement server is chosen to generally match a processing power of the first server it was chosen to replace.

21. The method for delivering content over the Internet, as recited in claim 17, wherein the second subset generally matches the processing power of the first subset of the plurality of servers.

22. The method for delivering content over the Internet, as recited in claim 21, wherein a number of processing cores of the second subset is equal to the number of processing cores of the first subset.

23. A non-transitory machine-readable medium having machine-executable instructions for performing the machine-implementable method for delivering content over the network of claim 17.

24. A method for delivering content over the Internet using a plurality of points of presence (PoPs) that are geographically distributed across the Internet, wherein the method comprises:

receiving a first domain resolution request with a PoP of the plurality of PoPs;

determining a first set of a plurality of servers allocated to a first domain with the PoP;

producing a first DNS solution corresponding to the first domain resolution request with the PoP;

returning the first DNS solution from the PoP;

receiving a second domain resolution request with the PoP;

determining a second set of the plurality of servers allocated to the first domain with the PoP;

producing a second DNS solution corresponding to the second domain resolution request with the PoP;

returning the second DNS solution from the PoP;

receiving a third domain resolution request with the PoP;

determining a third set of the plurality of servers allocated to the third domain with the PoP;

producing a third DNS solution corresponding to the third domain resolution request with the PoP;

returning the third DNS solution from the PoP, wherein;

the first, second and third domain resolution requests indicate the first domain,

a plurality of servers corresponding to a plurality of addresses,

the first DNS solution comprises a first plurality of addresses corresponding to at least a first subset of the first set,

the first DNS solution is determined at a first time,

the second DNS solution comprises a second plurality of addresses corresponding to at least a second subset of the second set,

the second DNS solution is determined at a second time,

the third DNS solution comprises a third plurality of addresses corresponding to at least a third subset of the third set,

the third DNS solution is determined at a third time, the first DNS solution includes a first address absent from the second DNS solution,

the first and second sets are different in that they reflect change in the plurality of servers allocated to the first domain,

the first address absent from the second DNS solution corresponds to a first server allocated to a second domain that is no longer allocated to the first domain at the second time,

the first address is no longer allocated for DNS solutions corresponding to the first domain after the first time and before the third time,

the first address is removed from allocation for DNS solutions corresponding to the domain based, at least in part, on activity associated with the domain relative to a first threshold,

the third DNS caching solution includes the first address absent from the second solution,

the first caching server is allocated for DNS solutions corresponding to the first domain or content originator at the third time, and

the first caching server is allocated for DNS solutions corresponding to the first domain based, at least in part, on activity associated with the domain relative to a second threshold.

25. The method for delivering content over the Internet, as recited in claim 24, wherein the change in the plurality of servers allocated to a domain is based, at least in part, on one or more of:

a content originator and/or content object; and

an associated service level.

26. The method for delivering content over the Internet, as recited in claim 24, wherein the change in the plurality of servers allocated to a domain is based, at least in part, on a server associated with the server being utilized above or below a certain threshold.