TECHNIQUES FOR DISTRIBUTED CACHE MANAGEMENT

• US 20110191541A1
• Filed: 01/29/2010
• Published: 08/04/2011
• Est. Priority Date: 01/29/2010
• Status: Active Grant

• Current Assignee: Eastman Kodak Company, Micro Focus Software, Inc. (Open Text Corporation)
• Original Assignee: Micro Focus Software, Inc. (Open Text Corporation)
• Inventors: Lowry, Lee Edward, Carter, Stephen R., Thurgood, Brent
• Granted Patent: US 9,952,968 B2
• Time in Patent Office: Days
• US Class Current: 711/119
• CPC Class Codes: G06F 12/08 in hierarchically structured memory systems, e.g. virtual memory systems
• CPC Class Codes: G06F 12/0815 Cache consistency protocols
• CPC Class Codes: G06F 16/9574 of access to content, e.g. by caching
• CPC Class Codes: G06F 2212/264 Remote server
• CPC Class Codes: G06F 3/0481 based on specific properties of the displayed interaction object or a metaphor-based environment, e.g. interaction with desktop elements like windows or icons, or assisted by a cursor's changing behaviour or appearance
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching
• CPC Class Codes: H04L 67/5682 Policies or rules for updating, deleting or replacing the stored data

Abstract

Techniques for distributed cache management are provided. A server having backend resource includes a global cache and a global cache agent. Individual clients each have client cache agents and client caches. When data items associated with the backend resources are added, modified, or deleted in the client caches, the client cache agents report the changes to the global cache agent. The global cache agent records the changes and notifies the other client cache agents to update a status of the changes within their client caches. When the changes are committed to the backend resource each of the statuses in each of the caches are updated accordingly.

Claims

1. A method implemented and residing within a computer-readable storage medium that is executed by one or more processors of a network to perform the method, comprising:

configuring a global cache on a server to manage state changes for data items that are cached in multiple network clients;

receiving notice from a first agent, which processes on a first client, the notice indicating a pending change to a particular data item was made within a first cache of the first client;

recording the pending change within the global cache when the pending change comports with a policy; and

pushing the pending change to one or more second agents from the global cache or receiving a pull request from each second agent to pull the pending change from the global cache, each second agent processing on a different second client and each different second client having a second cache where the data items are being independently accessed.

2. The method of claim 1 further comprising, committing the pending change to a backend resource having the data items and instructing the first agent and the one or more second agents to remove a pending status from the particular data item to indicate that the pending change has been committed.

3. The method of claim 1, wherein configuring further includes configuring the global cache to record and manage the state changes for the data items whereas other data items that have not changed on the first client or the one or more second clients are not recorded in the global cache.

4. The method of claim 1, wherein receiving the notice further includes determining in response to the policy that the pending change is unauthorized and instructing the first agent to back out the pending change from the first cache on the first client.

5. The method of claim 1, wherein recording further includes maintaining an identity for a principal that made the pending change on the first client with the pending change for the particular data item in the global cache.

6. The method of claim 5, wherein pushing further includes providing the identity to each of the one or more second agents for retention in each of the one or more second caches.

7. The method of claim 6, wherein providing further includes:

receiving from a particular second agent a denial of the pending change along with a second principal identity;

evaluating a second policy using the second principal identity indicating that the second principal is authorized to issue the denial;

removing the pending change from the global cache; and

instructing the first agent and remaining ones of the second agents to back out the pending change.

8. The method of claim 1, wherein pushing further includes re-pagination of the one or more second caches by the one or more second agents in response to the pushed pending change.

9. The method of claim 1, wherein pushing further includes re-sorting of the one or more second caches by the one or more second agents in response to the pushed pending change when the pushed pending change is an add of the particular data item.

10. The method of claim 1, wherein pushing further includes recoding the pending change in a log along with a date and time stamp, a first client identifier for the first client and a principal identifier for a principal of the first client that initiated the pending change.

11. A method implemented and residing within a computer-readable storage medium that is executed by one or more processors of a network to perform the method, comprising:

receiving a pending change for a data item from a global agent that manages a global cache for a server;

determining whether to accept or deny the pending change for the data item and when accepted updating a client cache on a client with the pending change; and

repaginating and/or re-sorting the client cache when warranted by the pending change and when the pending change is accepted.

12. The method of claim 11 further comprising, making a second change to a different data item in the client cache and reporting the second change to the global agent, the global agent records the second change and pushes the second change to one or more second clients for updates to one or more second caches of the second clients or the global agent receives pull requests from the one or more second clients for each of the one or more second clients to pull the second change to their one or more second caches.

13. The method of claim 11, further comprising, making a second change to the data item in the client cache and reporting the second change to the global agent, the global agent records the second change and pushes the second change to one or more second clients for updates to one or more second caches of the second clients or the global agent receives pull requests from the one or more second clients for each of the one or more second clients to pull the second change to their one or more second caches.

14. The method of claim 11, wherein determining further includes denying the pending change for the data item in response to a policy and then instructing the global agent to back out the pending change from the global cache and instructing one or more second clients to back out the pending change for the data item in one or more second caches.

15. The method of claim 11, wherein determining further includes denying the pending change for the data item in response to a policy and in view of a principal identity associated with the pending change, the principal identity indicating a principal that made the pending change and then instructing the global agent to back out the pending change from the global cache and further instruct one or more second clients to back out the pending change for the data item in one or more second caches.

16. The method of claim 11, wherein determining further includes requesting a principal to accept or deny the pending change.

17. A multiprocessor-implemented system, comprising:

a global cache agent implemented in a computer-readable medium and to process on a server; and

a plurality of client cache agents implemented in computer-readable media, each client cache agent to process on a client and manage a client cache;

the global cache agent is configured to manage pending state changes for data items associated with a backend resource of the server via a global cache, the global cache agent is further configured to synchronize pending changes to the data items received from each of the client cache agents by receiving the pending changes from those client cache agents originating the pending changes and pushing the pending changes to those client cache agents that did not originate the pending changes or receiving pull requests from those client cache agents that did not originate the pending changes for those client cache agents to receive the pending changes.

18. The system of claim 17, wherein the global cache agent is configured to enforce a policy to determine whether to allow the pending changes.

19. The system of claim 17, wherein the global cache agent is configured to permit a particular client cache agent to reject a particular change to a particular data item and in response thereto instructs the other client cache agents to back out the particular change in their client caches.

20. The system of claim 17, wherein the client cache agents are configured to repaginate and/or re-sort their client caches when warranted by the pending changes and any current views of users for the client caches on the clients remain stable so the users do not lose positions or locations in their current views.