Virtual machine consolidation

A computer system, comprising:

• a processor;
• a memory device coupled to the processor;
• and a computer readable storage device coupled to the processor, wherein the storage device contains program code executable by the processor via the memory device to implement a method for reassigning failed jobs in a virtual network of virtual machines, said method comprising the steps of:
• calculating, by the processor, whether a job queue of the virtual network is overloaded as a function of a length of an extended job queue being greater than a length of the job queue;
• setting, by the processor, each job in the job queue to be processed in a scalable mode of operation as a function of the job queue being overloaded;
• defining, by the processor, a number of virtual machines in each scalable mode of operation;
• apportioning, by the processor, a job in the job queue to a virtual machine in the virtual network operating in the scalable mode of operation;
• failing, by the processor, to complete the job queued by the virtual machine;
• computing, by the processor, a probability of failing to complete the job by the virtual machine as a function of an amount of time to execute the job to completion, a repair time, a failure rate and an amount of time remaining to complete the job within a time designated by a service level agreement;
• and
• determining, by the processor, as a function of the probability of failing to complete the job, whether to complete the job queued by the virtual machine or transfer the job to a queue of a second virtual machine operating in a dynamic voltage and frequency scaling (DVFS) mode or an active mode.

A computer program product comprising:

• one or more computer readable hardware storage devices having computer readable program code stored therein, said program code containing instructions executable by one or more processors to implement a method for reassigning failed jobs in a virtual network of virtual machines, said method comprising the steps of:
• calculating, by the processor, whether a job queue of the virtual network is overloaded as a function of a length of an extended job queue being greater than a length of the job queue;
• setting, by the processor, each job in the job queue to be processed in a scalable mode of operation as a function of the job queue being overloaded;
• defining, by the processor, a number of virtual machines in each scalable mode of operation;
• apportioning, by the processor, a job in the job queue to a virtual machine in the virtual network operating in the scalable mode of operation;
• failing, by the processor, to complete the job queued by the virtual machine;
• computing, by the processor, a probability of failing to complete the job by the virtual machine as a function of an amount of time to execute the job to completion, a repair time, a failure rate and an amount of time remaining to complete the job within a time designated by a service level agreement;
• and
• determining, by the processor, as a function of the probability of failing to complete the job, whether to complete the job queued by the virtual machine or transfer the job to a queue of a second virtual machine operating in a dynamic voltage and frequency scaling (DVFS) mode or an active mode.