Identifying and resolving cache poisoning

• US 9,230,037 B2
• Filed: 01/16/2013
• Issued: 01/05/2016
• Est. Priority Date: 01/16/2013
• Status: Active Grant

• Current Assignee: SAP SE
• Original Assignee: SAP SE
• Inventors: Sinai, Eyal, Igelka, Or
• Primary Examiner(s): Li, Zhuo H
• Application Number:
  US13/743,043
• Publication Number:
  US 20140201457A1
• Time in Patent Office: 1,084 Days
• Field of Search: 711/118, 711/119, 711/134, 711/E12.001, 711/E12.017, 711/E12.023, 711/E12.043, 711/E12.069, 709/212, 709214-219
• US Class Current: 1/1
• CPC Class Codes: G06F 12/121 using replacement algorithms
• CPC Class Codes: G06F 16/9574 of access to content, e.g. by caching

Abstract

According to some embodiments, a method and apparatus are provided to receive, at a cache entity, a refresh request associated with a resource. A determination is made, via a processor, and based on the refresh request, to reload the resource from a server. The reloaded resource is replaced at the cache entity.

Claims

1. A method comprising:

receiving, at a cache entity, a first refresh request associated with a particular resource from a first unique client;

determining, via a processor, that the first refresh request associated with the particular resource from the first unique client does not indicate a defective copy of the particular resource at the cache entity based on determining that the first refresh request does not meet a predetermined number of refreshes coming from a predetermined number of unique clients;

receiving, at a cache entity, a second refresh request associated with the particular resource from a second unique client;

determining, via the processor, that the first refresh request associated with the particular resource from the first unique client and the second refresh request associated with the particular resource from the second unique client indicates a defective copy of the particular resource at the cache entity based on determining that the first refresh request and the second refresh request meet the predetermined number of refreshes coming from the predetermined number of unique clients;

in response to the predetermined number of refreshes coming from the predetermined number of unique clients being met, reloading the particular resource from a server; and

storing the reloaded resource at the cache entity.

2. The method of claim 1, wherein the determining that the first refresh request associated with the particular resource from the first unique client and the second refresh request associated with the particular resource from the second unique client meets the predetermined number of refreshes is further based on exceeding a reliability score associated with the particular resource.

3. The method of claim 2, wherein the reliability score is incremented based on a number of received refresh requests.

4. The method of claim 3, wherein the first refresh request is weighted based on the first unique client transmitting the first refresh request and the second refresh request is weighted based on the second unique client transmitting the second refresh request.

5. The method of claim 2, wherein the reliability score associated with the particular resource is based on an up-time of the server.

6. The method of claim 1, wherein the first refresh request comprises an HTTP GET request, and wherein the HTTP GET request comprises a field indicating that the first request is a refresh.

7. The method of claim 1, wherein the reloaded resource is replaced at the cache entity prior to an end of a cache entity time-out period.

8. The method of claim 1, wherein the defective copy comprises an incomplete copy of the particular resource.

9. The method of claim 1, wherein the defective copy comprises an incorrect copy of the particular resource.

10. A non-transitory computer-readable medium comprising instructions that when executed by a processor perform a method, the method comprising:

receiving, at a cache entity, a first refresh request associated with a particular resource from a first unique client;

determining, via a processor, that the first refresh request associated with the particular resource from the first unique client does not indicate a defective copy of the particular resource at the cache entity based on determining that the first refresh request does not meet a predetermined number of refreshes coming from a predetermined number of unique clients;

receiving, at a cache entity, a second refresh request associated with the particular resource from a second unique client;

determining, via the processor, that the first refresh request associated with the particular resource from the first unique client and the second refresh request associated with the particular resource from the second unique client indicates a defective copy of the particular resource at the cache entity based on determining that the first refresh request and the second refresh request meet the predetermined number of refreshes coming from the predetermined number of unique clients;

in response to the predetermined number of refreshes coming from the predetermined number of unique clients being met, reloading the particular resource from a server; and

storing the reloaded resource at the cache entity.

11. The medium of claim 10, wherein the determining that the first refresh request associated with the particular resource from the first unique client and the second refresh request associated with the particular resource from the second unique client meets the predetermined number of refreshes is further based on exceeding a reliability score associated with the particular resource.

12. The medium of claim 11, wherein the reliability score is incremented based on a number of received refresh requests.

13. The medium of claim 12, wherein the first refresh request is weighted based on the first unique client transmitting the first refresh request and the second refresh request is weighted based on the second unique client transmitting the second refresh request.

14. The medium of claim 11, wherein the reliability score associated with the particular resource is based on an up-time of the server.

15. The medium of claim 10, wherein the first refresh request comprises an HTTP GET request, and wherein the HTTP GET request comprises a field indicating that the first request is a refresh.

16. An apparatus comprising:

a processor;

a non-transitory computer-readable medium comprising instructions that when executed by the processor perform a method, the method comprising;

receiving, at a cache entity, a first refresh request associated with a particular resource from a first unique client;

determining, via the processor, that the first refresh request associated with the particular resource from the first unique client does not indicate a defective copy of the particular resource at the cache entity based on determining that the first refresh request does not meet a predetermined number of refreshes coming from a predetermined number of unique clients;

receiving, at a cache entity, a second refresh request associated with the particular resource from a second unique client;

determining, via the processor, that the first refresh request associated with the particular resource from the first unique client and the second refresh request associated with the particular resource from the second unique client indicates a defective copy of the particular resource at the cache entity based on determining that the first refresh request and the second refresh request meet the predetermined number of refreshes coming from the predetermined number of unique clients;

in response to the predetermined number of refreshes coming from the predetermined number of unique clients being met, reloading the particular resource from a server; and

storing the reloaded resource at the cache entity.

17. The apparatus of claim 16, wherein the determining that the first refresh request associated with the particular resource from the first unique client and the second refresh request associated with the particular resource from the second unique client meets the predetermined number of refreshes is further based on exceeding a reliability score associated with the particular resource.

18. The apparatus of claim 17, wherein the reliability score is incremented based on a number of received refresh requests.

19. The apparatus of claim 18, wherein the first refresh request is weighted based on the first unique client transmitting the first refresh request and the second refresh request is weighted based on the second unique client transmitting the second refresh request.

20. The apparatus of claim 17, wherein the reliability score associated with the particular resource is based on an up-time of the server.