The Metadata Quality of Service Differentiation for Multi-priority in Cloud Computing

To ensure the Quality of Service (QoS) of the high-priority requests, the paper proposes a Congestion Control Algorithm of Multi-Priority (CCAMP) which differentiates the QoS according to the priorities, CCAMP reserves queue buffer for the high-priority packets by dropping the low-priority packets in a certain probability. Moreover, the paper presents an improved EDF (Earliest Deadline First) schedule of multi-priority with the sliding window which sorts the packets according to the estimated completion time, the sliding window defines the time similarity, and the high-priority packets are scheduled in priority in the sliding window. The results of the experiments prove that CCAMP and the improved EDF schedule reduces the delay and the loss rate of the high-priority packages, they realize the QoS differentiation by priorities effectively.