11,102 research outputs found
Trace-Driven Simulation for Energy Consumption in High Throughput Computing Systems
High Throughput Computing (HTC) is a powerful paradigm allowing vast quantities of independent work to be performed simultaneously. However, until recently little evaluation has been performed on the energy impact of HTC. Many organisations now seek to minimise energy consumption across their IT infrastructure though it is unclear how this will affect the usability of HTC systems. We present here HTC-Sim, a simulation system which allows the evaluation of different energy reduction policies across an HTC system comprising a collection of computational resources dedicated to HTC work and resources provided through cycle scavenging -- a Desktop Grid. We demonstrate that our simulation software scales linearly with increasing HTC workload
Operating policies for energy efficient large scale computing
PhD ThesisEnergy costs now dominate IT infrastructure total cost of ownership, with datacentre
operators predicted to spend more on energy than hardware infrastructure in the
next five years. With Western European datacentre power consumption estimated at
56 TWh/year in 2007 and projected to double by 2020, improvements in energy efficiency
of IT operations is imperative. The issue is further compounded by social and
political factors and strict environmental legislation governing organisations.
One such example of large IT systems includes high-throughput cycle stealing distributed
systems such as HTCondor and BOINC, which allow organisations to leverage
spare capacity on existing infrastructure to undertake valuable computation.
As a consequence of increased scrutiny of the energy impact of these systems, aggressive
power management policies are often employed to reduce the energy impact
of institutional clusters, but in doing so these policies severely restrict the computational
resources available for high-throughput systems. These policies are often configured
to quickly transition servers and end-user cluster machines into low power
states after only short idle periods, further compounding the issue of reliability.
In this thesis, we evaluate operating policies for energy efficiency in large-scale
computing environments by means of trace-driven discrete event simulation, leveraging
real-world workload traces collected within Newcastle University.
The major contributions of this thesis are as follows:
i) Evaluation of novel energy efficient management policies for a decentralised
peer-to-peer (P2P) BitTorrent environment.
ii) Introduce a novel simulation environment for the evaluation of energy efficiency
of large scale high-throughput computing systems, and propose a generalisable
model of energy consumption in high-throughput computing systems.
iii
iii) Proposal and evaluation of resource allocation strategies for energy consumption
in high-throughput computing systems for a real workload.
iv) Proposal and evaluation for a realworkload ofmechanisms to reduce wasted task
execution within high-throughput computing systems to reduce energy consumption.
v) Evaluation of the impact of fault tolerance mechanisms on energy consumption
Improving Mobile Video Streaming with Mobility Prediction and Prefetching in Integrated Cellular-WiFi Networks
We present and evaluate a procedure that utilizes mobility and throughput
prediction to prefetch video streaming data in integrated cellular and WiFi
networks. The effective integration of such heterogeneous wireless technologies
will be significant for supporting high performance and energy efficient video
streaming in ubiquitous networking environments. Our evaluation is based on
trace-driven simulation considering empirical measurements and shows how
various system parameters influence the performance, in terms of the number of
paused video frames and the energy consumption; these parameters include the
number of video streams, the mobile, WiFi, and ADSL backhaul throughput, and
the number of WiFi hotspots. Also, we assess the procedure's robustness to time
and throughput variability. Finally, we present our initial prototype that
implements the proposed approach.Comment: 7 pages, 15 figure
A Survey of Green Networking Research
Reduction of unnecessary energy consumption is becoming a major concern in
wired networking, because of the potential economical benefits and of its
expected environmental impact. These issues, usually referred to as "green
networking", relate to embedding energy-awareness in the design, in the devices
and in the protocols of networks. In this work, we first formulate a more
precise definition of the "green" attribute. We furthermore identify a few
paradigms that are the key enablers of energy-aware networking research. We
then overview the current state of the art and provide a taxonomy of the
relevant work, with a special focus on wired networking. At a high level, we
identify four branches of green networking research that stem from different
observations on the root causes of energy waste, namely (i) Adaptive Link Rate,
(ii) Interface proxying, (iii) Energy-aware infrastructures and (iv)
Energy-aware applications. In this work, we do not only explore specific
proposals pertaining to each of the above branches, but also offer a
perspective for research.Comment: Index Terms: Green Networking; Wired Networks; Adaptive Link Rate;
Interface Proxying; Energy-aware Infrastructures; Energy-aware Applications.
18 pages, 6 figures, 2 table
Energy-efficient checkpointing in high-throughput cycle-stealing distributed systems
Checkpointing is a fault-tolerance mechanism commonly used in High Throughput Computing (HTC) environments to allow the execution of long-running computational tasks on compute resources subject to hardware or software failures as well as interruptions from resource owners and more important tasks. Until recently many researchers have focused on the performance gains achieved through checkpointing, but now with growing scrutiny of the energy consumption of IT infrastructures it is increasingly important to understand the energy impact of checkpointing within an HTC environment. In this paper we demonstrate through trace-driven simulation of real-world datasets that existing checkpointing strategies are inadequate at maintaining an acceptable level of energy consumption whilst maintaing the performance gains expected with checkpointing. Furthermore, we identify factors important in deciding whether to exploit checkpointing within an HTC environment, and propose novel strategies to curtail the energy consumption of checkpointing approaches whist maintaining the performance benefits
Powertrace: Network-level Power Profiling for Low-power Wireless Networks
Low-power wireless networks are quickly becoming a critical part of our everyday infrastructure. Power consumption is a critical concern, but power measurement and estimation is a challenge. We present Powertrace,
which to the best of our knowledge is the first system for network-level power profiling of low-power wireless systems. Powertrace uses power state tracking to estimate system power consumption and a structure called energy capsules to attribute energy consumption to activities such as packet transmissions and receptions. With Powertrace, the power consumption of a system can be broken down into individual activities which allows us to answer questions such as “How much energy is spent forwarding packets for node X?”, “How much energy
is spent on control traffic and how much on critical data?”, and “How much energy does application X account for?”. Experiments show that Powertrace is accurate to 94% of the energy consumption of a device. To
demonstrate the usefulness of Powertrace, we use it to experimentally analyze the power behavior of the proposed IETF standard IPv6 RPL routing protocol and a sensor network data collection protocol. Through using Powertrace, we find the highest power consumers and are
able to reduce the power consumption of data collection with 24%. It is our hope that Powertrace will help the community to make empirical energy evaluation a widely used tool in the low-power wireless research community toolbox
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