Automatically and dynamically reclaiming resources during virtual machine decommission

1. A method for reclaiming resources during virtual machine decommission, the method comprising:

receiving, by one or more computer processors, information regarding resource utilization of a virtual machine (VM);

determining, by one or more computer processors, whether the resource utilization of the VM is less than a first predetermined threshold;

determining, by one or more computer processors, whether a cluster utilization of the VM is greater than a second predetermined threshold;

determining, by one or more computer processors, whether a timer is active;

in response to determining that the timer is active, determining, by one or more computer processors, whether the timer has expired;

in response to determining that the timer has expired, determining, by one or more computer processors, at what time a dynamic decommission of the VM may occur, based, at least in part, on a VM resource utilization information finding; and

in response to the determined time the dynamic decommission of the VM can occur, triggering, by one or more computer processors, a dynamic decommission of the VM.

2. The method of claim 1 , further comprising:

determining, by one or more computer processors, that the resource utilization of the VM is not less than the first predetermined threshold; and

in response to determining that the timer is active, removing, by one or more computer processors, the timer.

3. The method of claim 1 , further comprising:

determining, by one or more computer processors, that the cluster utilization of the VM is not greater than the second predetermined threshold; and

in response to determining that the timer is active, removing, by one or more computer processors, the timer.

4. The method of claim 1 , further comprising:

in response to determining that the timer is not active, creating, by one or more computer processors, a new timer.

5. The method of claim 1 , wherein receiving information regarding resource utilization of a virtual machine (VM) comprises:

detecting, by one or more system resource monitors, a level of resource utilization of the VM; and

reporting, by one or more computer processors, the level of resource utilization of the VM to a resource manager.

6. The method of claim 5 , wherein the resource manager is configured to: release resources and determine whether the VM is a zombie.

7. The method of claim 1 , wherein triggering the dynamic decommission of the VM is initiated, in part, by the later in time of:

a system administrator, wherein the system administrator determines that no more applications (apps) will be distributed to the VM; and

an application (app) administrator, wherein the app administrator determines that a last app has finished running on the VM.

8. A computer program product comprising:

a computer readable storage medium and program instructions stored on the computer readable storage medium, the program instructions comprising:

program instructions to receive information regarding resource utilization of a virtual machine (VM);

program instructions to determine whether the resource utilization of the VM is less than a first predetermined threshold;

program instructions to determine whether a cluster utilization of the VM is greater than a second predetermined threshold;

program instructions to determine whether a timer is active;

program instructions to, in response to determining that the timer is active, determine whether the timer has expired;

in response to determining that the timer has expired, program instructions to determine at what time a dynamic decommission of the VM may occur, based, at least in part, on a VM resource utilization information finding; and

in response to the determined time the dynamic decommission of the VM can occur, program instructions to, in response to determining that the timer has expired, trigger a dynamic decommission of the VM.

9. The computer program product of claim 8 , further comprising:

program instructions to determine that the resource utilization of the VM is not less than the first predetermined threshold; and

program instructions to, in response to determining that the timer is active, remove the timer.

10. The computer program product of claim 8 , further comprising:

program instructions to determine that the cluster utilization of the VM is not greater than the second predetermined threshold; and

program instructions to, in response to determining that the timer is active, remove the timer.

11. The computer program product of claim 8 , further comprising:

program instructions to, in response to determining that the timer is not active, create a new timer.

12. The computer program product of claim 8 , wherein the program instructions to receive information regarding resource utilization of a virtual machine (VM) comprise:

program instructions to detect a level of resource utilization of the VM; and

program instructions to report the level of resource utilization of the VM to a resource manager.

13. The computer program product of claim 12 , wherein the resource manager is configured to: release resources and determine whether the VM is a zombie.

14. The computer program product of claim 8 , wherein the program instructions to trigger the dynamic decommission of the VM is initiated, in part, by the later in time of:

a system administrator, wherein the system administrator determines that no more applications (apps) will be distributed to the VM; and

an application (app) administrator, wherein the app administrator determines that a last app has finished running on the VM.

15. A computer system comprising:

one or more computer processors;

one or more computer readable storage media;

program instructions stored on the computer readable storage media for execution by at least one of the one or more computer processors, the program instructions comprising:

program instructions to receive information regarding resource utilization of a virtual machine (VM);

program instructions to determine whether the resource utilization of the VM is less than a first predetermined threshold;

program instructions to determine whether a cluster utilization of the VM is greater than a second predetermined threshold;

program instructions to determine whether a timer is active;

program instructions to, in response to determining that the timer is active, determine whether the timer has expired;

in response to determining that the timer has expired, program instructions to determine at what time a dynamic decommission of the VM may occur, based, at least in part, on a VM resource utilization information finding; and

in response to the determined time the dynamic decommission of the VM can occur, program instructions to, in response to determining that the timer has expired, trigger a dynamic decommission of the VM.

16. The computer system of claim 15 , further comprising:

program instructions to determine that the resource utilization of the VM is not less than the first predetermined threshold; and

program instructions to, in response to determining that the timer is active, remove the timer.

17. The computer system of claim 15 , further comprising:

program instructions to determine that the cluster utilization of the VM is not greater than the second predetermined threshold; and

program instructions to, in response to determining that the timer is active, remove the timer.

18. The computer system of claim 15 , further comprising:

program instructions to, in response to determining that the timer is not active, create a new timer.

19. The computer system of claim 15 , wherein the program instructions to receive information regarding resource utilization of a virtual machine (VM) comprise:

program instructions to detect a level of resource utilization of the VM; and

program instructions to report the level of resource utilization of the VM to a resource manager.

20. The computer system of claim 15 , wherein the program instructions to trigger the dynamic decommission of the VM is initiated, in part, by the later in time of:

a system administrator, wherein the system administrator determines that no more applications (apps) will be distributed to the VM; and

an application (app) administrator, wherein the app administrator determines that a last app has finished running on the VM.