Benefits and limitations of tapping into stored energy for datacenters

Research output: Chapter in Book/Report/Conference proceedingConference contribution

190 Scopus citations


Datacenter power consumption has a significant impact on both its recurring electricity bill (Op-ex) and one-time construction costs (Cap-ex). Existing work optimizing these costs has relied primarily on throttling devices or workload shaping, both with performance degrading implications. In this paper, we present a novel knob of energy buffer (eBuff) available in the form of UPS batteries in datacenters for this cost optimization. Intuitively, eBuff stores energy in UPS batteries during "valleys"-periods of lower demand, which can be drained during "peaks"-periods of higher demand. UPS batteries are normally used as a fail-over mechanism to transition to captive power sources upon utility failure. Furthermore, frequent discharges can cause UPS batteries to fail prematurely. We conduct detailed analysis of battery operation to figure out feasible operating regions given such battery lifetime and datacenter availability concerns. Using insights learned from this analysis, we develop peak reduction algorithms that combine the UPS battery knob with existing throttling based techniques for minimizing datacenter power costs. Using an experimental platform, we offer insights about Op-ex savings offered by eBuff for a wide range of workload peaks/valleys, UPS provisioning, and application SLA constraints. We find that eBuff can be used to realize 15-45% peak power reduction, corresponding to 6-18% savings in Op-ex across this spectrum. eBuff can also play a role in reducing Cap-ex costs by allowing tighter overbooking of power infrastructure components and we quantify the extent of such Cap-ex savings. To our knowledge, this is the first paper to exploit stored energy-typically lying untapped in the datacenter-to address the peak power draw problem.

Original languageEnglish (US)
Title of host publicationProceeding of the 38th Annual International Symposium on Computer Architecture, ISCA'11
Number of pages11
StatePublished - 2011
Event38th Annual International Symposium on Computer Architecture, ISCA'11 - San Jose, CA, United States
Duration: Jun 4 2011Jun 8 2011

Publication series

NameProceedings - International Symposium on Computer Architecture
ISSN (Print)1063-6897


Other38th Annual International Symposium on Computer Architecture, ISCA'11
Country/TerritoryUnited States
CitySan Jose, CA

All Science Journal Classification (ASJC) codes

  • Hardware and Architecture


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