Impact of DVFS on n-tier application performance
Qingyang Wang, Yasuhiko Kanemasa, Jack Li, Chien An Lai, Masazumi Matsubara, Calton Pu · 2013
Dynamic Voltage and Frequency Scaling (DVFS) has been widely deployed and proven to reduce energy consumption at low CPU utilization levels; however, our measurements of the n-tier application benchmark (RUBBoS) performance showed significant performance degradation at high utilization levels, with response time several times higher and throughput loss of up to 20%, when DVFS is turned on. Using a combination of benchmark measurements and simulation, we found two kinds of problems: large response time fluctuations due to push-back wave queuing in n-tier systems and throughput loss due to rapidly alternating bottlenecks. These problems arise from anti-synchrony between DVFS adjustment period and workload burst cycles (similar cycle length but out of phase). Simulation results (confirmed by extensive measurements) show the anti-synchrony happens routinely for a wide range of configurations. We show that a workload-sensitive DVFS adaptive control mechanism can disrupt the anti-synchrony and reduce the performance impact of DVFS at high utilization levels to 25% or less of the original.