Intelligent Pre-fetching using Compound Operations

• US 20080077655A1
• Filed: 09/22/2006
• Published: 03/27/2008
• Est. Priority Date: 09/22/2006
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Fuller, Jeffrey C., George, Mathew, Ganapathy, Ramanathan, Kruse, David M.
• Granted Patent: US 8,370,456 B2
• Time in Patent Office: Days
• US Class Current: 709/203
• CPC Class Codes: G06F 12/0862 with prefetch
• CPC Class Codes: G06F 2212/6028 Prefetching based on hints or prefetch instructions
• CPC Class Codes: G06F 9/383 Operand prefetching cache prefetching G06F12/0862
• CPC Class Codes: G06F 9/3842 Speculative instruction execution

Abstract

A system and method for pre-fetching data uses a combination of heuristics to determine likely next data retrieval operations and an evaluation of available resources for executing speculative data operations. When local resources, such as cache memory for storing speculative command results is not available, the compound operation request may not be sent. When resources on a server-side system are insufficient, only the primary command of a compound operation request may be processed and speculative command requests may be rejected. Both local computing resources and network resources may be evaluated when determining whether to build or process a compound operations request.

Claims

1. In a computer data processing environment having a reader process communicatively coupled to a service process, a method of reducing network traffic between the reader and service processes comprising:

receiving a compound request at the service processor comprising a first request for a primary operation and a second request for a secondary operation;

processing the primary operation;

determining if the second request for the secondary operation is a speculative secondary operation;

performing the speculative secondary operation when a condition is satisfied; and

sending the results of the primary operation and the secondary operation.

2. The method of claim 1, further comprising caching the results of the secondary operation at the reader process.

3. The method of claim 2, further comprising clearing the cache when a file associated with the secondary operation is closed.

4. The method of claim 1, wherein the condition is a size of the return result.

5. The method of claim 1, wherein the condition is an availability of processing resources at the service process.

6. The method of claim 1, wherein the condition is a result returned by the primary operation.

7. The method of claim 1, further comprising building the compound request at the reader process using a heuristic to predict the secondary operation based on the primary operation.

8. The method of claim 7, wherein building the compound request at the reader process comprises building the compound request after evaluating that sufficient cache and processing resources are available to manage a response to the compound request.

9. The method of claim 1, further comprising building the compound request at an input/output operation above the reader process.

10. The method of claim 1, further comprising building the compound request at an application above the reader process.

11. The method of claim 1, wherein the second request comprises a plurality of secondary operations.

12. The method of claim 1, wherein the secondary operation is an operation for reading data.

13. A computer-readable medium having computer-executable instructions for implementing a method comprising:

examining a first request requiring a primary operation on a server;

determining a secondary operation related to the primary operation;

attaching the secondary operation to the request and marking the secondary operation speculative;

receiving results from the primary and secondary operations;

caching the results of the secondary operation;

supplying the results of secondary operation responsive to receiving a second request for the secondary operation.

14. The computer-readable medium of claim 13, further comprising determining that resources are available for caching the results of the secondary operation before attaching the secondary operation to the request.

15. The computer-readable medium of claim 13, wherein attaching the secondary operation to the request is performed at a reader service.

16. The computer-readable medium of claim 13, wherein attaching the secondary operation to the request is performed at an input/output service.

17. The computer-readable medium of claim 13, wherein attaching the secondary operation to the request is performed at an application.

18. A computer-readable medium having computer-executable instructions for implementing a method comprising:

receiving a compound request having a primary operation and a secondary operation, the secondary operation dependent upon a result from the primary operation;

dispatching the primary operation;

receiving a first result corresponding to primary operation;

extracting data from the first result;

inserting the data from the result into the secondary operation;

receiving a second result corresponding to the secondary operation; and

responding to the compound request with the first and second results.

19. The computer-readable medium of claim 18, further comprising evaluating resources available to process the secondary operation before accepting the secondary operation.

20. The computer-readable medium of claim 19, further comprising sending a notification to a calling party that the secondary operation is not accepted when the evaluation indicates resources are not available.