Virtual machine scheduling based on task characteristic

Credit scheduler, an original Xen virtual machine scheduler, uses a boost mechanism to improve responsiveness. However, the original boost mechanism is applied only to inactive virtual machines. Because of this, if virtual machine scheduling delay time increases, the I/O performance of an active virtual machine dramatically decreases. However, when the boost mechanism of a previous credit scheduler is applied to an active virtual machine, the allocation equality can become unbalanced. This research study proposes a boost mechanism that can be applied to an active virtual machine. Evaluation of the results showed that, when compared to the previous credit scheduler, the proposed method both did not upset the fairness of the CPU allocation between the virtual machines and improved the I/O performance.