Method and system for regulating background tasks using performance measurements

• US 7,765,553 B2
• Filed: 12/13/2004
• Issued: 07/27/2010
• Est. Priority Date: 07/16/1999
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Bolosky, William J., Douceur, John R.
• Primary Examiner(s): An; Meng-Ai
• Assistant Examiner(s): Huaracha; Willy W
• Application Number:
  US11/010,471
• Publication Number:
  US 20050132375A1
• Time in Patent Office: 2,052 Days
• Field of Search: 718/1, 718/8, 718/100, 718/102, 718/103, 718/107, 718/108
• US Class Current: 718/107
• CPC Class Codes: G06F 9/4881 Scheduling strategies for dispatcher, e.g. round robin, multi-level priority queues

Abstract

A method and system for regulating tasks of background processes so as to reduce interference with foreground processes. The progress rate of a background task (e.g., amount of work performed per unit time) is measured and evaluated against a target amount. If the progress rate appears degraded, the background task is suspended for a computed time interval so as to back off from its interference with a foreground process. Each time the progress rate appears degraded, the time interval is exponentially increased from its previous value up to a maximum, however if the performance appears normal, the time interval is reset to a minimum. Evaluation of the work is statistically based so as to eliminate variations in measurements, and automatic calibration of the target amount is provided, as is a mechanism for prioritizing multiple background tasks.

Claims

1. In a computing environment, having a computing system comprising a processor executing a background task, the computing system performing a method, comprising:

evaluating the performance of the background task relative to a target performance of the background task, the target performance including a target value indicative of a target amount of work for the background task to perform, by at least comparing a measured value of the amount of work performed by the background task against the target value; and

(i) if the performance is acceptable, resetting a suspend time for delaying execution of the background task to a predefined starting value that is between zero and a maximum value, and returning to executing the background task;

(ii) if the performance is not acceptable;

(1) delaying execution of the background task for the suspend time;

(2) after delaying for the suspend time, increasing the suspend time;

(3) ensuring that the increased suspend time is at least a minimum value that is greater than zero, and no more than the maximum value;

(4) determining whether the background task is critical, and if so, adjusting the suspend time before delaying for the suspend time; and

returning to executing the background task.

2. The method of claim 1, wherein the target value is based on empirical testing and a plurality of statistical samplings relative to a required time to perform an operation corresponding to the background task on an unloaded resource.

3. The method of claim 2, wherein if the performance is not determined by current performance data, the maintaining suspend time and returning to executing the background task.

4. The method of claim 1, further comprising, when the performance is acceptable, delaying for a working rate delay time before returning to executing the background task.

5. The method of claim 1, wherein evaluating the performance of the background task includes statistically combining current measured data with previous measured data.

6. The method of claim 1, wherein the background task is executed for a limited time, and wherein evaluating the performance of the background task includes evaluating a count of a number of operations performed during the limited time.

7. The method of claim 6, wherein the background task is executed for a limited time, and wherein evaluating the performance of the background task includes evaluating a total real time taken for the operations to complete.

8. At least one computer-readable storage medium having computer-executable instructions, which when executed, perform the method of claim 1.

9. The method of claim 1, wherein the target performance is a user defined and manually entered value.

10. The method of claim 1, wherein the target performance is based on past performance data of the background task.

11. The method of claim 1, wherein increasing the suspend time comprises increasing the suspend time exponentially.

12. In a computing environment, a computing system comprising:

a processor;

a task regulator comprising software code that authorizes execution of a task of a background process;

a performance evaluator comprising software code that compares a measured progress of the task against past performance data of the background task to provide progress information;

a computation mechanism comprising software code coupled to the performance evaluator to receive the progress information, and further coupled to the task regulator to control subsequent authorization of the background task based on the progress information, and storage media storing computer-executable instructions, which when executed, implement the method recited in claim 1.

13. The computing system of claim 12, wherein the measured progress of the task corresponds to an amount of work per unit time performed by the task.

14. The computing system of claim 12, wherein the progress information comprises a suspension time.

15. The computing system of claim 14, wherein the computation mechanism determines the suspension time based at least in part on whether or not the task is critical.

16. The computing system of claim 14, wherein the computation mechanism determines the suspension time based at least in part on a previous suspension time.

17. The computing system of claim 12, further comprising a calibration mechanism that receives the measured progress data and statistically combines the measured progress data with the performance data.

18. The computing system of claim 12, wherein the task of the background process executes for a limited time, and wherein the measured progress data include a count of a number of operations performed during the limited time and a total real time taken for the operations to complete.

19. The computing system of claim 12, wherein increasing the maximum value represents a worst-case background task resumption time.