Networks of Tiny Switches (NoTS): In search of network power efficiency and proportionality
Joseph ChabarekSujata Banerjee (HP Labs)Puneet Sharma (HP Labs)
Jayaram Mudigonda (HP Labs)Paul Barford
WEED 2013June 24, 2013
Motivation• 2% (estimate) of world carbon output • Increasing number of users and traffic is a
long term characteristic of the Internet• Always-on-at-full power• Increasing pressure from consumers and
regulators to be “green”• Public commitments from vendors [Smart2020]
[SMART 2020] SMART 2020: Enabling the low carbon economy in the information age. http://www.smart2020.org/_assets/files02_Smart2020Report.pdf
Networks of Tiny Switches (NoTS)
Devices have high static power consumption (60-80% max consumption at idle loads)
Use low radix (port count), small form factor switches as a primitive to assemble low powered networks.
Deploy power-proportional networks (i.e. small efficient switches can give finer granularity of control)
NoTS tradeoffs
• [Backplane:] NoTS devices have fewer communication channels (more external links)
• [Processor:] lower power processors can be used in a NoTS device (more devices)
• [Features:] There are feature-rich small switches in the market today
• [Power Supply/Fans:] NoTS devices have simple a/c to d/c converters and typically do not have fans
• [Fixed vs Chassis:] NoTS devices would be built as single chip fixed switches.
NoTS evaluation
• Enterprise transformation• Datacenter evaluation• Network simulation capability for large
networks
Enterprise transformation
• Observed traffic from a large IT company• Topology standard core/distribution/access• Access through core, traffic primarily North-
South
Enterprise Network
Down links
...
...Up links
...
...
...
Enterprise Network
Large Switch
... ......Tiny Switch
...
Tiny Switch
...
Tiny Switch
...
Tiny Switch
...
Large SwitchLarge Switch
Example enterprise NoTS construction
Existing infrastructure:600 provisioned hosts218 total host ports active355 total ports administratively upAllocated: Deploy NoTS for 600 hosts, power infrastructure for 218 up ports Packing: Pack 355 up ports onto the fewest devices and power infrastructure Realized: Power down unused linecards
NoTS vs. deployed devices shows uniform decrease in consumption
Datacenter topologies
• Are there any good low radix datacenter topologies that scale?
• What are the performance and power tradeoffs?
• Static and simulator evaluation (1800 hosts)
NoTS topologies (radix < 20): Torus, B-Cube, RRG9Standard topologies: Fat-tree, RRG48
Topology performance characteristics
NoTS topologies incur a longer average path length with randomized host placement
Multihomed topologies fare better against node failures
Topology performance characteristics
Tolopogy Normalized bisection bandwidth
Torus 0.19
BCube 1.14
FatTree 1,2 1.0
RRG9 0.32
RRG42 0.87
Dynamic power consumption simulation
Simulated result of NoTS realized power savings
Result more dramatic with measurement based chassis and per-link costs
NoTS contributions
• Proposed a novel power-aware network architecture primitive
• NoTS network transformations for enterprise and datacenter contexts
• Evaluated power, performance tradeoffs of existing and proposed network architectures
Related work• Trends and system
design– Energy conservation
in networks [GS03]
– Alternative systems [MCK03]
– Helios[FAR10]
– Access networks[GOM11]
• Tools and testbeds– Optimization – Network simulation
and emulation
[GS03] M. Gupta and S. Singh. Greening of the Internet. In Proceedings of ACM SIGCOMM ’03[MCK03] N. McKeown, “Scaling Routers Using Optics ,http://yuba.stanford.edu/~nickm/talks, October 2003.[FAR10] Farrington et al. Helios: A Hybrid Electrical/Optical Switch Arch. For Modular Data Centers. In Proceedings of ACM SIGCOMM ’10[GOM11] Goma et al. Insomnia in the Access . In Proceedings of ACM SIGCOMM ’11
Related work
• Power-aware networks– Energy related
metrics[AA10]
– Adaptive bandwidth [EEE]
– Datacenters[BH10]
– Best practices [HP10]
[BH10] B. Heller, S. Seetharaman, P. Mahadevan,Y. Yiakoumis, P. Sharma, S. Banerjee, andN. McKeown. ElasticTree: Saving Energy in Data Center Networks. NSDI ’10.[AA10] A.P. Bianzino, A.K. Raju, and D. Rossi. Apple-to-Apple: A Framework Analysis forEnergy-Efficiency in Networks. In Proceedings of GREENMETRICS, New York, NY, May 2010.[EEE] Energy Efficient Digital Networks. http://efficientnetworks.lbl.gov/enet-adaptive.html, 2010[HP10] P. Mahadevan, P. Sharma, S. Banerjee, and P. Ranganathan. Energy Aware Network Operations. In IFIP Networking, May 2009
• Related Systems– Wireless– PC’s
Future work
• Simulation/emulation of more topologies under individually adverse traffic patterns
• Explore novel network device architectures and packages
• Evaluate the role of optical interconnects
