  The rapid growth of data volume brings big challenges to the data center
computing, and energy efficiency is one of the most concerned problems.
Researchers from various fields are now proposing solutions to green the data
center operations. Power usage effectiveness metric plays an important role in
the energy saving research. However, the exising usage effectiveness metrics
focus on measuring the relationship between the total facility energy consumed
and the IT equipment energy consumed, without reflecting the energy efficiency
of applications. In this paper, we analyze the requirements of
application-level metrics for power usage efficiency of the data centers, and
propose two novel energy efficiency metrics to provide strong guidance and
useful insight to data center design and optimization. We conduct comprehensive
experiments in the practical data centers using BigDataBench, a big data
benchmark suite, and the results demonstrate the rationality and efficiency of
AxPUE in measuring the actual computation energy consumption in data centers.
