ESTABLISHING CACHES THAT PROVIDE DYNAMIC, AUTHORITATIVE DNS RESPONSES

• US 20160028847A1
• Filed: 07/23/2014
• Published: 01/28/2016
• Est. Priority Date: 07/23/2014
• Status: Abandoned Application

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Tuliani, Jonathan Roshan, Mani, Pradeepkumar, Griffin, William J., Maltz, David A., Bozic, Kresimir, Lientz, Andrew, Bradshaw, Gareth R., Flavel, Ashley Ryan, Ashutosh, Kumar, Gupta, Tushar, Gaitonde, Vithalprasad Jayendra, Chintalapati, V R Kishore, Black, Benjamin J., Hayrapetyan, Levon, Maskara, Rajesh Kumar, Sain, Sourav
• Application Number:
  US14/339,097
• Publication Number:
  US 20160028847A1
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 61/58 Caching of addresses or names
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching

Abstract

Embodiments are directed to establishing caches that provide authoritative domain name system (DNS) answers to DNS requests. In one scenario, a computer system establishes a cache that stores authoritative DNS answers to DNS queries. The cache corresponds to a specified DNS zone that includes authoritative DNS answers for a subset of DNS queries. The cache is configured to store the authoritative DNS answers for at least a specified period of time during which the authoritative DNS answers are updatable. The cache then receives an update indicating that at least one cached DNS answer is out-of-date and the computer system purges the out-of-date DNS answer from the cache, ensuring that the cache continually provides authoritative DNS answers for DNS queries assigned to the specified DNS zone.

Claims

1. At a computer system including at least one processor, a computer-implemented method for establishing caches that provide authoritative domain name system (DNS) answers to DNS requests, the method comprising:

an act of establishing a cache that stores authoritative DNS answers to DNS queries, the cache corresponding to at least one specified DNS zone scope that includes authoritative DNS answers for a subset of DNS queries, the cache being configured to store the authoritative DNS answers for at least a specified period of time during which the authoritative DNS answers are updatable;

an act of receiving, at the cache, an update indicating that at least one cached DNS answer is out-of-date; and

an act of purging the out-of-date DNS answer from the cache, ensuring that the cache continually provides authoritative DNS answers for DNS queries assigned to the specified DNS zone.

2. The method of claim 1, wherein the specified period of time for the cache to store the authoritative DNS answers is configurable for each DNS answer.

3. The method of claim 1, wherein the specified period of time for the cache to store the authoritative DNS answers is different than a time specified by a time-to-live (TTL) designation in the DNS answer, such that the specified period of time overrides the time specified by the TTL designation.

4. The method of claim 1, wherein a plurality of caches is established including at least a first cache corresponding to a first specified DNS zone, and a second, default cache configured to store a specified subset of DNS answers.

5. The method of claim 4, wherein the second, default cache is configured to store negative DNS answers indicating that the DNS name does not exist.

6. The method of claim 4, wherein purging the out-of-date DNS answer from the cache further comprises replacing the purged out-of-date DNS answer with and updated DNS answer provided with the received update.

7. The method of claim 1, wherein the DNS zone covers a specified geographical area, such that DNS requests received from that geographical area will be answered by the DNS zone specified for that geographical area.

8. The method of claim 7, wherein the computer system provides DNS service for a plurality of DNS zones, each DNS zone having a corresponding cache.

9. The method of claim 1, wherein at least one of the DNS answers provided by the cache is digitally pre-signed.

10. At a computer system including at least one processor, a computer-implemented method for dynamically providing authoritative DNS answers to DNS requests, the method comprising:

an act of determining, based on one or more factors, which of a plurality of zone scopes is to handle a received DNS request, each zone scope including at least one cache scope that stores authoritative DNS answers for a subset of DNS requests;

an act of accessing at least one authoritative DNS answer stored in the cache scope of the determined zone scope; and

an act of providing the accessed authoritative DNS answer from the accessed cache scope.

11. The method of claim 10, wherein the authoritative DNS answers are provided in a traffic-managed domain.

12. The method of claim 11, wherein the traffic-managed domain has a plurality of traffic managers, each traffic manager including a profile.

13. The method of claim 12, wherein the traffic managers perform load balancing over different zone scopes, such that different zone scopes provide authoritative DNS answers for equivalent queries.

14. The method of claim 12, wherein the traffic managers answer subsequent DNS requests for the same DNS name from the established cache.

15. The method of claim 10, wherein the cache scope is continually updated as DNS answers change at the origin.

16. A computer system comprising the following:

one or more processors;

one or more computer-readable storage media having stored thereon computer-executable instructions that, when executed by the one or more processors, cause the computing system to perform a method for dynamically providing authoritative DNS answers to DNS requests, the method comprising the following;

an act of determining, based on one or more factors, which of a plurality of zone scopes is to handle a received DNS request, each zone scope including at least one cache scope that stores authoritative DNS answers for a subset of DNS requests;

an act of determining that a specified DNS answer is not stored within the cache scope of the determined zone scope;

an act of sending a request for a current DNS answer, the request including an indication of the DNS zone scope that was determined to provide an authoritative DNS answer for the received DNS request; and

upon receiving the updated DNS answer for the determined DNS zone scope, an act of providing the received DNS answer to the DNS request.

17. The computer system of claim 16, wherein the indication of the specified DNS zone scope that was authorized to provide an authoritative DNS answer for the received DNS request is included in DNS extension metadata.

18. The computer system of claim 16, further comprising caching the received DNS answer for subsequent queries.

19. The computer system of claim 16, wherein out-of-date DNS answers are purged from the cache scopes, ensuring that the cache scopes continually provide authoritative DNS answers for DNS queries assigned to the specified DNS zone scopes.

20. The computer system of claim 16, wherein the received, updated DNS answer for the determined DNS zone scope includes a DNS answer update that overwrites the current DNS answer.