System and Method of Accessing a Document Efficiently Through Multi-Tier Web Caching

• US 20120271852A1
• Filed: 06/28/2012
• Published: 10/25/2012
• Est. Priority Date: 06/30/2004
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Eric Russell Fredricksen, Fritz John Schneider, Georges Harik, Jeffrey Adgate Dean, Niels Provos, Sanjay Ghemawat
• Inventors: Fredricksen, Eric Russell, Schneider, Fritz John, Dean, Jeffrey Adgate, Ghemawat, Sanjay, Provos, Niels, Harik, Georges
• Granted Patent: US 8,788,475 B2
• Time in Patent Office: Days
• US Class Current: 707/782
• CPC Class Codes: G06F 16/93 Document management systems
• CPC Class Codes: G06F 16/9574 of access to content, e.g. by caching
• CPC Class Codes: Y10S 707/99931 Database or file accessing
• CPC Class Codes: Y10S 707/99932 Access augmentation or optimizing

Abstract

Upon receipt of a document request, a client assistant examines its cache for the document. If not successful, a server searches for the requested document in its cache. If the server copy is still not fresh or not found, the server seeks the document from its host. If the host cannot provide the copy, the server seeks it from a document repository. Certain documents are identified from the document repository as being fresh or stable. Information about each of these identified documents is transmitted to the server which inserts entries into an index if the index does not already contain an entry for the document. If and when this particular document is requested, the document will not be present in the server, however the server will contain an entry directing the server to obtain the document from the document repository rather than the document'"'"'s web host.

Claims

1. A system for domain name server (DNS) caching comprising:

a DNS cache configured to store DNS address records, wherein each DNS address record corresponds to a hostname; and

a controller coupled to the DNS cache configured to;

initiate a DNS resolution request for a hostname close to expiration of a corresponding DNS address record in the DNS cache; and

update the corresponding DNS address record based upon a result of the DNS resolution request.

2. The system of claim 1, wherein the controller is further configured to replace the corresponding DNS address record with a result of the DNS resolution request.

3. The system of claim 1, wherein the controller is further configured to extend a time-to-live (TTL) value of the corresponding DNS address record based upon the result of the DNS resolution request.

4. The system of claim 1, wherein the controller is further configured to detect an impending or recent expiration of a DNS address record in the DNS cache.

5. The system of claim 1, wherein the controller is configured to initiate DNS resolution requests for predetermined hostnames in order to store corresponding DNS address records in the DNS cache.

6. A system for domain name server (DNS) caching comprising:

a DNS cache configured to store DNS address records, wherein each DNS address record corresponds to a hostname; and

a controller coupled to the DNS cache and configured to;

in response to determining predetermined criteria are met, initiate a DNS resolution request for a hostname corresponding to a DNS address record, wherein the DNS resolution request is initiated prior to a need for a resolution; and

update the corresponding record based upon a result of the DNS resolution request.

7. The system of claim 6, wherein the controller is further configured to replace the corresponding DNS address record with a result of the DNS resolution request.

8. The system of claim 6, wherein the controller is further configured to extend a time-to-live (TTL) value of the corresponding DNS address record based upon the result of the DNS resolution request.

9. The system of claim 6, wherein the controller is further configured to detect an impending or recent expiration of a DNS address record in the DNS cache.

10. The system of claim 6, wherein the controller is configured to initiate DNS resolution requests for predetermined hostnames in order to store corresponding DNS address records in the DNS cache.

11. A method for domain name server (DNS) caching with one or more processors that utilize a DNS to resolve network addresses, comprising:

initiating a DNS resolution request for a hostname close to an expiration of a corresponding DNS address record in a DNS cache; and

updating the corresponding DNS address record in the DNS cache based upon a result of the DNS resolution request,

wherein the initiating and updating steps are performed by the one or more processors.

12. The method of claim 11, wherein the updating comprises replacing the corresponding DNS address record with a result of the DNS resolution request.

13. The method of claim 11, wherein the updating further comprises extending a time-to-live (TTL) value of the corresponding DNS address record based upon the result of the DNS resolution request.

14. The method of claim 11, further comprising detecting an impending or expiration of a DNS address record in the DNS cache.

15. The method of claim 11, further comprising initiating DNS resolution requests for predetermined hostnames in order to store corresponding DNS address records in the DNS cache.

16. A method for domain name server (DNS) caching with one or more processors that utilize a DNS to resolve network addresses, comprising:

in response to determining predetermined criteria are met, initiating a DNS resolution request for a hostname corresponding to a DNS address record, wherein the DNS resolution request is initiated prior to a need for a resolution; and

updating the corresponding DNS address record in the DNS cache based upon a result of the DNS resolution request,

wherein the initiating and updating steps are performed by the one or more processors.

17. The method of claim 16, wherein the updating comprises replacing the corresponding DNS address record with a result of the DNS resolution request.

18. The method of claim 16, wherein the updating further comprises extending a time-to-live (TTL) value of the corresponding DNS address record based upon the result of the DNS resolution request.

19. The method of claim 16, further comprising detecting an impending or expiration of a DNS address record in the DNS cache.

20. The method of claim 16, further comprising initiating DNS resolution requests for predetermined hostnames in order to store corresponding DNS address records in the DNS cache.