OPTIMIZING MEMORY MANAGEMENT OF AN APPLICATION RUNNING ON A VIRTUAL MACHINE

• US 20120137101A1
• Filed: 11/07/2011
• Published: 05/31/2012
• Est. Priority Date: 11/30/2010
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Arcese, Mauro, Sidoti, Stefano
• Granted Patent: US 8,886,866 B2
• Time in Patent Office: Days
• US Class Current: 711/170
• CPC Class Codes: G06F 9/5016 the resource being the memory

Abstract

A method, system and computer program product for optimizing memory usage of an application running on a virtual machine. A virtual machine memory block is pre-allocated and the average memory usage of the virtual machine is periodically computed using statistics collected from the virtual machine through an API. If the memory usage average becomes higher than a maximum threshold, then a recovery mode is entered by releasing the virtual machine memory block and forcing the running application to reduce its processing activity; optionally, a garbage collector cycle can be forced. If the computed memory usage average becomes lower than a minimum threshold value, which is lower than the maximum threshold value, then a normal mode is entered by re-allocating the virtual machine memory block and forcing the running application to resumes its normal processing activity. Optionally, when the virtual machine is idle, a deep garbage collection is forced.

Claims

1. A method for optimizing memory usage of an application running on a virtual machine, said virtual machine providing a monitoring application programming interface (API) to communicate with said virtual machine and said virtual machine including a garbage collector, the method comprising:

self-allocating a virtual machine memory block;

periodically collecting and storing virtual machine memory usage statistics;

periodically computing an average virtual machine memory usage from the memory usage statistics in a time window;

entering into a recovery mode by releasing the virtual machine memory block and forcing the running application to reduce its processing activity in response to the computed virtual machine memory usage average becoming higher than a first threshold; and

entering, by a processor, into a normal mode by re-self-allocating the virtual machine memory block and forcing the running application to resume its normal processing activity in response to the computed memory usage average becoming lower than a second threshold.

2. The method as recited in claim 1 further comprising:

setting a virtual machine state indicator to the normal mode, and wherein the entering into the recovery mode and the entering into the normal mode further comprise;

in response to the virtual machine state indicator being set to the normal mode and in response to the computed memory usage average exceeding the first threshold performing, the method further comprises;

switching the state indicator from the normal mode into the recovery mode;

releasing the self-allocated memory block to the virtual machine;

notifying the running application that a low memory condition occurs to force the running application to reduce its processing activity; and

returning to the periodically computing step;

returning to the periodically computing step in response to the virtual machine state indicator being set to the normal mode and in response to the computed memory usage average not exceeding a maximum threshold;

in response to the virtual machine state indicator being set to the recovery mode and in response to the computed memory usage average descending below the second threshold, the method further comprises;

switching the state indicator from the recovery mode into the normal mode;

self-allocating the virtual machine memory block;

notifying the running application that the low memory condition occurs to force the running application to resume its normal processing activity; and

returning to the periodically computing step; and

returning to the periodically computing step in response to the virtual machine state indicator being set to the recovery mode and in response to the computed memory usage average not descending under the second threshold.

3. The method as recited in claim 2, wherein the running application performs an initial callback request to receive a notification and wherein the notifying of the running application comprises in sending a callback notification to the running application.

4. The method as recited in claim 1 further comprising:

forcing the virtual machine to perform a garbage collector cycle in response to the virtual machine memory usage average becoming higher than the first threshold.

5. The method as recited in claim 1, wherein the first threshold value is greater than the second threshold value.

6. The method as recited in claim 1, wherein the first and second thresholds are set as configuring parameters.

7. The method as recited in claim 1 further comprising:

testing if the virtual machine is idle; and

forcing the virtual machine to perform a garbage collector cycle in response to the virtual machine being idle.

8. The method as recited in claim 7, wherein the testing if the virtual machine is idle comprises:

periodically collecting and storing virtual machine CPU usage and garbage collector activity statistics;

periodically computing an average virtual machine CPU usage and an average garbage collector activity from the collected and stored statistics; and

testing if the computed virtual machine CPU usage average is lower than a configurable third threshold and if the garbage collector activity is null.

9. A computer program product embodied in a computer readable storage medium for optimizing memory usage of an application running on a virtual machine, said virtual machine providing a monitoring application programming interface (API) to communicate with said virtual machine and said virtual machine including a garbage collector, the computer program product comprising the programming instructions for:

self-allocating a virtual machine memory block;

periodically collecting and storing virtual machine memory usage statistics;

periodically computing an average virtual machine memory usage from the memory usage statistics in a time window;

entering into a recovery mode by releasing the virtual machine memory block and forcing the running application to reduce its processing activity in response to the computed virtual machine memory usage average becoming higher than a first threshold; and

entering into a normal mode by re-self-allocating the virtual machine memory block and forcing the running application to resume its normal processing activity in response to the computed memory usage average becoming lower than a second threshold.

10. The computer program product as recited in claim 9 further comprising the programming instructions for:

setting a virtual machine state indicator to the normal mode, and wherein the entering into the recovery mode and the entering into the normal mode further comprise;

in response to the virtual machine state indicator being set to the normal mode and in response to the computed memory usage average exceeding the first threshold performing, the computer program product further comprises the programming instructions for;

switching the state indicator from the normal mode into the recovery mode;

releasing the self-allocated memory block to the virtual machine;

notifying the running application that a low memory condition occurs to force the running application to reduce its processing activity; and

returning to the periodically computing step;

returning to the periodically computing step in response to the virtual machine state indicator being set to the normal mode and in response to the computed memory usage average not exceeding a maximum threshold;

in response to the virtual machine state indicator being set to the recovery mode and in response to the computed memory usage average descending below the second threshold, the computer program product further comprises the programming instructions for;

switching the state indicator from the recovery mode into the normal mode;

self-allocating the virtual machine memory block;

notifying the running application that the low memory condition occurs to force the running application to resume its normal processing activity; and

returning to the periodically computing step; and

returning to the periodically computing step in response to the virtual machine state indicator being set to the recovery mode and in response to the computed memory usage average not descending under the second threshold.

11. The computer program product as recited in claim 10, wherein the running application performs an initial callback request to receive a notification and wherein the notifying of the running application comprises in sending a callback notification to the running application.

12. The computer program product as recited in claim 9 further comprising the programming instructions for:

forcing the virtual machine to perform a garbage collector cycle in response to the virtual machine memory usage average becoming higher than the first threshold.

13. The computer program product as recited in claim 9, wherein the first threshold value is greater than the second threshold value.

14. The computer program product as recited in claim 9, wherein the first and second thresholds are set as configuring parameters.

15. The computer program product as recited in claim 9 further comprising the programming instructions for:

testing if the virtual machine is idle; and

forcing the virtual machine to perform a garbage collector cycle in response to the virtual machine being idle.

16. The computer program product as recited in claim 15, wherein the programming instructions for testing if the virtual machine is idle comprises the programming instructions for:

periodically collecting and storing virtual machine CPU usage and garbage collector activity statistics;

periodically computing an average virtual machine CPU usage and an average garbage collector activity from the collected and stored statistics; and

testing if the computed virtual machine CPU usage average is lower than a configurable third threshold and if the garbage collector activity is null.

17. A system, comprising:

a memory unit for storing a computer program for optimizing memory usage of an application running on a virtual machine, said virtual machine providing a monitoring application programming interface (API) to communicate with said virtual machine and said virtual machine including a garbage collector; and

a processor coupled to the memory unit, wherein the processor, responsive to the computer program, comprises;

circuitry for self-allocating a virtual machine memory block;

circuitry for periodically collecting and storing virtual machine memory usage statistics;

circuitry for periodically computing an average virtual machine memory usage from the memory usage statistics in a time window;

circuitry for entering into a recovery mode by releasing the virtual machine memory block and forcing the running application to reduce its processing activity in response to the computed virtual machine memory usage average becoming higher than a first threshold; and

circuitry for entering into a normal mode by re-self-allocating the virtual machine memory block and forcing the running application to resume its normal processing activity in response to the computed memory usage average becoming lower than a second threshold.

18. The system as recited in claim 17, wherein the processor further comprises:

circuitry for setting a virtual machine state indicator to the normal mode, and wherein the entering into the recovery mode and the entering into the normal mode further comprise;

in response to the virtual machine state indicator being set to the normal mode and in response to the computed memory usage average exceeding the first threshold performing, the processor further comprises;

circuitry for switching the state indicator from the normal mode into the recovery mode;

circuitry for releasing the self-allocated memory block to the virtual machine;

circuitry for notifying the running application that a low memory condition occurs to force the running application to reduce its processing activity; and

circuitry for returning to the periodically computing step;

circuitry for returning to the periodically computing step in response to the virtual machine state indicator being set to the normal mode and in response to the computed memory usage average not exceeding a maximum threshold;

in response to the virtual machine state indicator being set to the recovery mode and in response to the computed memory usage average descending below the second threshold, the processor further comprises;

circuitry for switching the state indicator from the recovery mode into the normal mode;

circuitry for self-allocating the virtual machine memory block;

circuitry for notifying the running application that the low memory condition occurs to force the running application to resume its normal processing activity; and

circuitry for returning to the periodically computing step; and

circuitry for returning to the periodically computing step in response to the virtual machine state indicator being set to the recovery mode and in response to the computed memory usage average not descending under the second threshold.

19. The system as recited in claim 18, wherein the running application performs an initial callback request to receive a notification and wherein the notifying of the running application comprises in sending a callback notification to the running application.

20. The system as recited in claim 17, wherein the processor further comprises:

circuitry for forcing the virtual machine to perform a garbage collector cycle in response to the virtual machine memory usage average becoming higher than the first threshold.

21. The system as recited in claim 17, wherein the first threshold value is greater than the second threshold value.

22. The system as recited in claim 17, wherein the first and second thresholds are set as configuring parameters.

23. The system as recited in claim 17, wherein the processor further comprises:

circuitry for testing if the virtual machine is idle; and

circuitry for forcing the virtual machine to perform a garbage collector cycle in response to the virtual machine being idle.

24. The system as recited in claim 23, wherein the circuitry for testing if the virtual machine is idle comprises:

circuitry for periodically collecting and storing virtual machine CPU usage and garbage collector activity statistics;

circuitry for periodically computing an average virtual machine CPU usage and an average garbage collector activity from the collected and stored statistics; and

circuitry for testing if the computed virtual machine CPU usage average is lower than a configurable third threshold and if the garbage collector activity is null.