Power Management of Online Data-Intensive Services
Venue
Proceedings of the 38th ACM International Symposium on Computer Architecture (2011)
Publication Year
2011
Authors
David Meisner, Christopher M. Sadler, Luiz André Barroso, Wolf-Dietrich Weber, Thomas F. Wenisch
BibTeX
Abstract
Much of the success of the Internet services model can be attributed to the
popularity of a class of workloads that we call Online Data-Intensive (OLDI)
services. These workloads perform significant computing over massive data sets per
user request but, unlike their offline counterparts (such as MapReduce
computations), they require responsiveness in the sub-second time scale at high
request rates. Large search products, online advertising, and machine translation
are examples of workloads in this class. Although the load in OLDI services can
vary widely during the day, their energy consumption sees little variance due to
the lack of energy proportionality of the underlying machinery. The scale and
latency sensitivity of OLDI workloads also make them a challenging target for power
management techniques. We investigate what, if anything, can be done to make OLDI
systems more energy-proportional. Specifically, we evaluate the applicability of
active and idle low-power modes to reduce the power consumed by the primary server
components (processor, memory, and disk), while maintaining tight response time
constraints, particularly on 95th-percentile latency. Using Web search as a
representative example of this workload class, we first characterize a production
Web search workload at cluster-wide scale. We provide a fine-grain characterization
and expose the opportunity for power savings using low-power modes of each primary
server component. Second, we develop and validate a performance model to evaluate
the impact of processor- and memory-based low-power modes on the search latency
distribution and consider the benefit of current and foreseeable low-power modes.
Our results highlight the challenges of power management for this class of
workloads. In contrast to other server workloads, for which idle low-power modes
have shown great promise, for OLDI workloads we find that energy-proportionality
with acceptable query latency can only be achieved using coordinated, full-system
active low-power modes.
