Automatic invalidation of cached data

• US 6,934,720 B1
• Filed: 08/04/2001
• Issued: 08/23/2005
• Est. Priority Date: 08/04/2001
• Status: Active Grant

• Current Assignee: eBay Inc., Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Lockert, Thorsten, Anton, Jesse, Liu, Xiang, Jacobs, Lawrence
• Primary Examiner(s): Alam, Shahid
• Assistant Examiner(s): Truong, Cam Y T
• Application Number:
  US09/922,617
• Time in Patent Office: 1,480 Days
• Field of Search: 707/10, 707200-205, 707/206, 708/229, 711/105, 711118-124, 711/141, 711/154, 705/26, 705/27
• US Class Current: 1/1
• CPC Class Codes: G06F 16/9574 of access to content, e.g. by caching
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

A system and method are provided for automatically invalidating cached data. A cache system caches data from a data server (e.g., web server, application server, database). When a request is received at the cache system from a client, particularly a request to alter or replace a set of data, the request is examined and may be compared to a set of rules or data relationships that invoke automatic invalidation. Based on a pattern or content of the request (e.g., an identifier of data to be changed), the cache system identifies and invalidates a cached data item without waiting for the data server to receive the request, process it and instruct the cache system to invalidate the data item. In a cache system comprising multiple caches, one cache may notify another when automatic invalidation is necessary.

Claims

1. A method of automatically invalidating data cached in a cache system physically separate from a data server configured to originate data to be cache system, the method comprising:

at a cache system physically separate from a data server configured to originate data to be cached in the cache system, caching a first data item received from the data server for service in response to request to view said first data item;

receiving at the cache system a change request from a client to alter a data item;

comparing said change request to a set of rules for determining when to automatically invalidate said first data item;

identifying a relationship between a second data item and a first data item, wherein said identifying a relationship comprises comparing a pattern of said first request to a first rule for determining when to automatically invalidate a set of data, wherein said first rule comprises a first pattern for identifying a request in response to which a set of data may be automatically invalidated, and further comprises a second pattern, different from said first pattern, to identify said set of data to be automatically invalidated; and

automatically invalidating said first data item at the cache system in response to said change request.

2. The method of claim 1, wherein said data item to be altered comprises said first data item.

3. The method of claim 1, wherein said automatically invalidating comprises identifying a relationship between said data item to be altered and said first data item.

4. The method of claim 1, wherein said cache system comprises multiple caches and said receiving occurs at a first of the multiple caches, the method further comprising:

sending a notification of said automatic invalidation from the first cache of the multiple caches to a second cache of the multiple caches.

5. A method of operating a cache system to facilitate automatic invalidation of cached data, the method being performed at the cache system and comprising:

at a cache system physically separate from a data server configured to originate data to be cached in the cached system, caching a first set of data received from the data server;

receiving at the cache system a first request from a client to change a second set of data;

retrieving from said first request an identifier of said second set of data;

comparing said first request to a set of rules for determining when to automatically invalidate said first set of data;

identifying a relationship between said second set of data and said first set of data, wherein said identifying a relationship comprises comparing a pattern of said first request to a first rule for determining when to automatically invalidate a set of data, where said first rule comprises a first pattern for identifying a request in response to which a set of data may be automatically invalidated, and further comprises a second pattern, different from said first pattern, to identify said set of data to be automatically invalidated;

automatically invalidating said first set of data in the cache system without awaiting an invalidating communication from the data server.

6. The method of claim 5, wherein said second set of data comprises said first set of data.

7. The method of claim 5, wherein said second set of data is a later version of said first set of data.

8. The method of claim 5, wherein the cache system comprises multiple caches and:

wherein said caching comprises caching said first set of data at a first cache of the multiple caches; and

wherein said automatically invalidating is performed at a second cache of the multiple caches;

the method further comprising notifying the first cache, by the second cache, of said automatic invalidation.

9. A method of automatically invalidating cached data, comprising:

at a cache system physically separate from a data server configured to originate data to be cached in the cache system, caching a first set of data at a caching system for serving in response to a view request, wherein said view request comprises a request to view said first set of data, and wherein said first set of data is received from a data server;

receiving at the caching system a change request from a client, wherein said change request comprises a request to change said first set of data;

identifying said first set of data from said change request;

identifying a relationship between a second data item and a first data item, wherein said identifying a relationship comprises comparing a pattern of said first request to a first rule for determining when to automatically invalidate a set of data, wherein said first rule comprises a first pattern for identifying a request in response to which a set of data may be automatically invalidated, and further comprises a second pattern, different from said first pattern, to identify said set of data to be automatically invalidated;

comparing said change request to a set of rules for determining when to automatically invalidate said first set of data; and

automatically invalidating said cached first set of data without waiting for the data server to implement said change request, wherein invalidating said cached first set of data is in response to the view request.

10. The method of claim 9, wherein said data server is notified of said change request only after said automatic invalidation of said cached first set of data.

11. The method of claim 9, wherein said first set of data comprises a first user'"'"'s bid on an item being auctioned in an electronic auction, and wherein said change request comprises a second user'"'"'s bid on said item.

12. The method of claim 9, wherein said first set of data comprises information concerning one or more products at a publicly accessible network location, and wherein said change request comprises a change to said list of products.

13. The method of claim 9, wherein said receiving a change request comprises receiving a sequence of communications matching a predetermined pattern.

14. A computer readable storage medium storing instructions that, when executed by a computing device, cause the computing device to perform a method of operating a cache system to facilitate automatic invalidation of cached data, the method being performed at the cache system and comprising:

at a cache system physically separate from a data server configured to originate data to be cached in the cache system, caching a first set of data received from the data server;

receiving at the cache system a first request from a client to change a second set of data;

retrieving from said first request an identifier of said second set of data;

comparing said change request to a set of rules for determining when to automatically invalidate said first set of data;

identifying a relationship between said second set of data and said first set of data, wherein said identifying a relationship comprises comparing a pattern of said first request to a first rule for determining when to automatically invalidate a set of data, where said first rule comprises a first pattern for identifying a request in response to which a set of data may be automatically invalidated, and further comprises a second pattern, different from said first pattern, to identify said set of data to be automatically invalidated;

automatically invalidating said first set of data in the cache system without awaiting an invalidation communication form the data server.

15. A computer readable storage medium storing instructions that, when executed by a computing device to perform a method of automatically invalidating cached data, the method comprising:

at a cache system physically separate from a data server configured to originate data to be cached in the cache system, caching a first set of data at a caching system for serving in response to a view request, wherein said view request comprises a request to view said first set of data, and wherein said first ser of data is received from a data server;

receiving at the caching system a change request from a client, wherein said change request comprises a request to change said first set of data;

identifying said first set of data from said change request;

comparing said change request to a set of rules for determining when to automatically invalidate said first set of data;

identifying a relationship between a second set of data and said first set of data, wherein said identifying a relationship comprises comparing a pattern of said first request to a first rule for determining when to automatically invalidate a set of data, where said first rule comprises a first pattern for identifying a request in response to which a set of data may be automatically invalidated, and further comprises a second pattern, different from said first pattern, to identify said set of data to be automatically invalidated;

automatically invalidating said cached first set of data without for the data server to implement said change request, wherein invalidating said cached first set of data is in response to the view request.

16. A cache system configured to automatically invalidate cached data, comprising:

a first cache configured to cache data received from a data server, wherein said first cache is separate from said data server, and wherein the data server is coupled to the cache system via a network link;

a data service module configured to server a first set of cached data in response to a first data view request from a client;

a set of rules for determining when said first set of cached data is to be automatically invalidated in response to a data change request;

a comparing module for comparing said first data change request to the set of rules for determining when to automatically invalidate said first set of cached data;

identifying a relationship between a second set of data and said first set of data, wherein said identifying a relationship comprises comparing a pattern of said first request to a first rule for determining when to automatically invalidate a set of data, where said first rule comprises a first pattern for identifying a request in response to which a set of data may be automatically invalidated, and further comprises a second pattern, different from said first pattern, to identify said set of data to be automatically invalidated;

an invalidation module configured to automatically invalidate said first set of cached data when a first data change request is received from a client;

wherein said automatic invalidation is performed at the cache system before the data server is notified of said first data change request.

17. The cache system of claim 16, wherein said first cache comprises said invalidation module.

18. The cache system of claim 16, further comprising a user interface configured to facilitate the creation of one of said rules.

19. The cache system of claim 16, wherein said first data change request comprises a predetermined sequence of communications.

20. The cache system of claim 16, further comprising:

a second cache;

wherein said second cache is notified by said first cache of said automatic invalidation.