Methods, systems and computer program products for preemptive avoidance of constraints for shared resources

• US 6,016,503 A
• Filed: 08/29/1997
• Issued: 01/18/2000
• Est. Priority Date: 08/29/1997
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Overby, Linwood Hugh Jr., Rajaraman, Balachandar
• Primary Examiner(s): An, Meng-Ai T.
• Assistant Examiner(s): EL HADY, NABIL M
• Application Number:
  US08/920,975
• Time in Patent Office: 872 Days
• Field of Search: 395/674, 395/651, 395/653, 395/683, 395/729, 395/732, 395/849, 395/861, 370/235, 370/229, 709/5, 709/303, 709/104, 709/105, 713/1, 713/100, 710/241, 710/244, 710/29, 710/41, 710/6, 710/17, 710/18, 706/8
• US Class Current: 718/104
• CPC Class Codes: G06F 2209/5019 Workload prediction
• CPC Class Codes: G06F 9/50 Allocation of resources, e.g. of the central processing unit [CPU]

Abstract

Methods, systems (apparatus) and computer program products are provided which control access to a shared resource in a data processing system by predicting utilization of the shared resource based upon historical utilization of the shared resource. Users of the shared resource are then notified of a potential shortage of the shared resource if the prediction predicts that the shared resource will be over-utilized. The prediction may utilize a linear extrapolation to predict future utilization of the share resource. Furthermore, the interval between predictions of the future utilization may be based on time, number of utilization events or a combination of the two.

Claims

1. A method of controlling access to a shared data processing resource in a data processing system, the method comprising the steps of:

predicting future utilization of the shared data processing resource based upon a rate of change of utilization of the shared data processing resource determined from historical utilization of the shared data processing resource over a predefined number of events or predetermined time intervals; and

notifying users of the shared data processing resource of a potential future shortage of the shared data processing resource by setting a critical flag if the current utilization of the shared resource reaches a predefined maximum utilization value, and by setting a constraint flag if said step of predicting predicts that the utilization of shared data processing resource will be greater than the predefined maximum utilization value of the shared resource.

2. A method according to claim 1, wherein said step of predicting utilizes linear extrapolation based upon the rate of change of utilization of the shared resource to predict a future utilization of the shared resource.

3. A method according to claim 1, wherein said step of predicting utilizes a filtered extrapolation based upon the rate of change of utilization of the shared resource to predict a future utilization of the shared resource.

4. A method according to claim 1, wherein said step of predicting utilization of the shared resource comprises the steps of:

determining a change in utilization of the shared resource over a predefined number of events;

determining a current utilization value for the shared resource; and

predicting a future utilization based upon the change in utilization and the current utilization.

5. A method according to claim 4, wherein said step of predicting a future utilization of the shared resource comprises the step of adding to the current utilization value the change in utilization of the shared resource so as to provide a prediction of the utilization of the shared resource after a subsequent predefined number of events.

6. A method according to claim 4, wherein said step of predicting a future utilization of the shared resource comprises the steps of:

dividing the change in utilization by the predefined number of events to provide an incremental change value;

multiplying the incremental change value by the predefined number of events into the future of the future utilization to provide a future differential value; and

summing the future differential value and the current utilization to predict the future utilization.

7. A method according to claim 4, wherein the predefined number of events comprises a predefined period of time.

8. A method according to claim 4, wherein the predefined number of events comprises a predefined number of utilization events.

9. A method according to claim 5, wherein said step of notifying users of the shared resource, comprises notifying users of a shortage of the shared resource if said step of adding to the current utilization results in the prediction of the utilization of the shared resource exceeding the predefined maximum utilization of the shared resource.

10. A method according to claim 1, further comprising the steps of:

maintaining the constraint flag as set until the occurrence of at least one of a slope of the change of utilization of the shared resource becomes negative and the prediction of the utilization of the shared resource predicts that the shared resource will no longer be greater than the predefined maximum utilization value of the shared resource.

11. A method according to claim 10, further comprising the steps of:

resetting the critical flag when the current utilization of the shared resource falls below the predefined maximum of the shared resource utilization.

12. A method according to claim 1, wherein said step of predicting utilization of the shared resource comprises the step of predicting, at a predefined interval, a stretch between a current utilization of the shared resource and the predefined maximum utilization of the shared resource, and, wherein said step of notifying comprises the step of notifying users of the shared resource of a potential future shortage of the shared resource if said step of predicting predicts that the stretch is within the predefined interval.

13. A method according to claim 12, wherein said step of predicting, at a predefined interval, a duration, comprises the steps of:

determining a change in utilization of the shared resource over the predefined interval to provide a utilization differential rate;

determining the current utilization of the shared resource;

determining the difference between the current utilization and the predefined maximum utilization to provide a utilization differential value; and

dividing the utilization differential value by the utilization differential rate.

14. A method according to claim 13, wherein said step of notifying comprises the step of notifying users of the shared resource of a potential future shortage of the shared resource if said step of dividing results is a value of less than the predefined interval.

15. A method according to claim 14, wherein the predefined interval is a predefined time period.

16. A method according to claim 14, wherein the predefined interval is a predefined number of utilization events.

17. A method according to claim 16, wherein the events are selected from the group comprising buffer allocates, frees, expansions and contractions.

18. A method according to claim 14, wherein the predefined interval is defined by a combination of a predefined number of events and a predefined time interval.

19. A system for controlling access to a shared data processing resource in a data processing system, comprising:

means for predicting future utilization of the shared data processing resource based upon a rate of change of utilization of the shared data processing resource determined from historical utilization of the shared data processing resource over a predefined number of events or predetermined time intervals; and

means for notifying users of the shared data processing resource of a potential future shortage of the shared data processing resource by setting a critical flag if the current utilization of the shared resource reaches a predefined maximum utilization value, and by setting a constraint flag if said means for predicting predicts that the utilization of shared data processing resource will be greater than the predefined maximum utilization value of the shared resource.

20. A system according to claim 19, wherein said means for predicting utilization of the shared resource comprises:

means for determining a change in utilization of the shared resource over a predefined number of events;

means for determining a current utilization value for the shared resource; and

means for predicting a future utilization of the shared resource based upon the change in utilization and the current utilization.

21. A system according to claim 20, wherein said means for predicting a future utilization of the shared resource comprises means for adding to the current utilization value the change in utilization of the shared resource so as to provide a prediction of the utilization of the shared resource after a subsequent predefined number of events.

22. A system according to claim 20, wherein said means for predicting a future utilization of the shared resource comprises:

means for dividing the change in utilization by the predefined number of events to provide an incremental change value;

means for multiplying the incremental change value by the predefined number of events into the future of the future utilization to provide a future differential value; and

means for summing the future differential value and the current utilization to predict the future utilization.

23. A system according to claim 20, wherein the predefined number of events comprises a predefined number of utilization events.

24. A system according to claim 19, wherein said means for predicting utilization of the shared resource comprises means for predicting, at a predefined interval, a stretch between a current utilization of the shared resource and the predefined maximum utilization of the shared resource, and, wherein said means for notifying comprises means for notifying users of the shared resource of a potential future shortage of the shared resource if said means for predicting predicts that the stretch is within the predefined interval.

25. A computer program product for controlling access to a shared data processing resource in a data processing system, comprising:

a computer-readable storage medium having computer-readable program code means embodied in said medium, said computer-readable program code means comprising;

computer-readable program code means for predicting future utilization of the shared data processing resource based upon a rate of change of utilization of the shared data processing resource determined from historical utilization of the shared data processing resource over a predefined number of events or predetermined time intervals; and

computer-readable program code means for notifying users of the shared data processing resource of a potential future shortage of the shared data processing resource by setting a critical flag if the current utilization of the shared resource reaches a predefined maximum utilization value, and by setting a constraint flag if said computer-readable program code means for predicting predicts that the utilization of shared data processing resource will be greater than the predefined maximum utilization value of the shared resource.

26. A computer program product according to claim 25, wherein said computer-readable program code means for predicting utilization of the shared resource comprises:

computer-readable program code means for determining a change in utilization of the shared resource over a predefined number of events;

computer-readable program code means for determining a current utilization value for the shared resource; and

computer-readable program code means for predicting a future utilization based upon the change in utilization and the current utilization.

27. A computer program product according to claim 26, wherein said computer-readable program code means for predicting a future utilization of the shared resource comprises computer-readable program code means for adding to the current utilization value to the change in utilization of the shared resource so as provide a prediction of the utilization of the shared resource after a subsequent predefined number of events.

28. A computer program product according to claim 26, wherein said computer-readable program code means for predicting a future utilization of the shared resource comprises:

computer-readable program code means for dividing the change in utilization by the predefined number of events to provide an incremental change value;

computer-readable program code means for multiplying the incremental change value by the predefined number of events into the future of the future utilization to provide a future differential value; and

computer-readable program code means for summing the future differential value and the current utilization to predict the future utilization.

29. A computer program product according to claim 26, wherein the predefined number of events comprises a predefined number of utilization events.

30. A computer program product according to claim 25, wherein said computer-readable program code means for predicting utilization of the shared resource comprises computer-readable program code means for predicting, at a predefined interval, a stretch between a current utilization of the shared resource and the predefined maximum utilization of the shared resource, and, wherein said computer-readable program code means for notifying comprises computer-readable program code means for notifying users of the shared resource of a potential future shortage of the shared resource if said computer-readable program code means for predicting predicts that the stretch is within the predefined interval.