Systems and methods for using excitement values to predict future access to resources

• US 7,386,675 B2
• Filed: 10/21/2005
• Issued: 06/10/2008
• Est. Priority Date: 10/21/2005
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: Isilon Systems Incorporated (Dell Technologies Inc.)
• Inventors: Fachan, Neal T.
• Primary Examiner(s): Sparks; Donald
• Assistant Examiner(s): DETSCHEL, FREDERICK W
• Application Number:
  US11/256,317
• Publication Number:
  US 20070094452A1
• Time in Patent Office: 963 Days
• Field of Search: None
• US Class Current: 711/137
• CPC Class Codes: G06F 12/0862 with prefetch
• CPC Class Codes: G06F 12/0866 for peripheral storage systems, e.g. disk cache

Abstract

Systems and methods using an excitement protocol enable prediction of which blocks of a resource to prefetch and store in memory. The system maintains a set of excitement values corresponding to the resource being accessed. The system also maintains a threshold. As blocks of the resource are requested, the system updates the set of excitement values. The system compares the excitement level to the threshold to determine whether to prefetch the corresponding resource block.

Claims

1. A system for improved access to a set of resources comprising:

a processor configured to;

access a set of resources, the set of resources comprising resource blocks;

maintain a set of excitements, the set of excitements comprising excitement values that correspond to a plurality of the resource blocks;

maintain a threshold;

receive a request for a resource block;

update the set of excitements, wherein a change in the excitement values is related to the requested resource block, and wherein the change in the excitement values comprises a convolution; and

determine a set of predicted resource blocks by comparing the excitement values to the threshold.

2. A system for improved access to a set of resources comprising:

a processor configured to;

access a set of resources, the set of resources comprising resource blocks;

maintain a set of excitements, the set of excitements comprising excitement values that correspond to a plurality of the resource blocks;

maintain a threshold;

receive a request for a resource block;

update the set of excitements, wherein a change in the excitement values is related to the requested resource block, and wherein the change in excitement values comprises a function depending on an offset from the requested resource block; and

determine a set of predicted resource blocks by comparing the excitement values to the threshold.

3. The system of claim 2, wherein the function enables just-in-time access to the set of predicted resource blocks.

4. The system of claim 2, wherein the function is at least one of inversely proportional to the offset over a range of offsets, substantially constant over a range of offsets, non-zero over a range of offsets, symmetric with respect to zero offset, zero for negative offsets, and less than or equal to zero for a first range of offsets and greater than or equal to zero for a second range of offsets.

5. A method of predicting future accesses to a resource, the method comprising:

accessing a set of resources, the set of resources comprising resource blocks;

maintaining a set of excitements, the set of excitements comprising excitement values that correspond to a plurality of the resource blocks;

maintaining a threshold;

receiving a request for a resource block;

accessing the requested resource block;

updating the set of excitements, further comprising calculating a change in the excitement values that is related to the requested resource block, wherein the step of calculating the change in the excitement values further comprises calculating an offset from the requested resource block;

determining a set of predicted resource blocks, further comprising comparing the excitement values to the threshold;

accessing the set of predicted resource blocks; and

returning the requested and predicted resource blocks.

6. The method of claim 5, wherein the step of calculating an offset further comprises evaluating a function that is inversely proportional to the offset over a range of offsets or substantially constant over a range of offsets.