• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
  • Skip to footer

Electrical Engineering News and Products

Electronics Engineering Resources, Articles, Forums, Tear Down Videos and Technical Electronics How-To's

  • Products / Components
    • Analog ICs
    • Connectors
    • Microcontrollers
    • Power Electronics
    • Sensors
    • Test and Measurement
    • Wire / Cable
  • Applications
    • Automotive/Transportation
    • Industrial
    • IoT
    • Medical
    • Telecommunications
    • Wearables
    • Wireless
  • Resources
    • DesignFast
    • Digital Issues
    • Engineering Week
    • Oscilloscope Product Finder
    • Podcasts
    • Webinars / Digital Events
    • White Papers
    • Women in Engineering
  • Videos
    • Teschler’s Teardown Videos
    • EE Videos and Interviews
  • Learning Center
    • EE Classrooms
    • Design Guides
      • WiFi & the IOT Design Guide
      • Microcontrollers Design Guide
      • State of the Art Inductors Design Guide
      • Power Electronics & Programmable Power
    • FAQs
    • Ebooks / Tech Tips
  • EE Forums
    • EDABoard.com
    • Electro-Tech-Online.com
  • 5G

No-wait data centers

July 17, 2014 By EurekAlert

Big websites usually maintain their own “data centers,” banks of tens or even hundreds of thousands of servers, all passing data back and forth to field users’ requests. Like any big, decentralized network, data centers are prone to congestion: Packets of data arriving at the same router at the same time are put in a queue, and if the queues get too long, packets can be delayed.

At the annual conference of the ACM Special Interest Group on Data Communication, in August, MIT researchers will present a new network-management system that, in experiments, reduced the average queue length of routers in a Facebook data center by 99.6 percent — virtually doing away with queues. When network traffic was heavy, the average latency — the delay between the request for an item of information and its arrival — shrank nearly as much, from 3.56 microseconds to 0.23 microseconds.

Like the Internet, most data centers use decentralized communication protocols: Each node in the network decides, based on its own limited observations, how rapidly to send data and which adjacent node to send it to. Decentralized protocols have the advantage of an ability to handle communication over large networks with little administrative oversight.

The MIT system, dubbed Fastpass, instead relies on a central server called an “arbiter” to decide which nodes in the network may send data to which others during which periods of time. “It’s not obvious that this is a good idea,” says Hari Balakrishnan, the Fujitsu Professor in Electrical Engineering and Computer Science and one of the paper’s coauthors.

With Fastpass, a node that wishes to transmit data first issues a request to the arbiter and receives a routing assignment in return. “If you have to pay these maybe 40 microseconds to go to the arbiter, can you really gain much from the whole scheme?” says Jonathan Perry, a graduate student in electrical engineering and computer science (EECS) and another of the paper’s authors. “Surprisingly, you can.”

Division of labor
Balakrishnan and Perry are joined on the paper by Amy Ousterhout, another graduate student in EECS; Devavrat Shah, the Jamieson Associate Professor of Electrical Engineering and Computer Science; and Hans Fugal of Facebook.

The researchers’ experiments indicate that an arbiter with eight cores, or processing units, can keep up with a network transmitting 2.2 terabits of data per second. That’s the equivalent of a 2,000-server data center with gigabit-per-second connections transmitting at full bore all the time.

“This paper is not intended to show that you can build this in the world’s largest data centers today,” Balakrishnan says. “But the question as to whether a more scalable centralized system can be built, we think the answer is yes.

Moreover, “the fact that it’s two terabits per second on an eight-core machine is remarkable,” Balakrishnan says. “That could have been 200 gigabits per second without the cleverness of the engineering.”

The key to Fastpass’s efficiency is a technique for splitting up the task of assigning transmission times so that it can be performed in parallel on separate cores. The problem, Balakrishnan says, is one of matching source and destination servers for each time slot.

“If you were asked to parallelize the problem of constructing these matchings,” he says, “you would normally try to divide the source-destination pairs into different groups and put this group on one core, this group on another core, and come up with these iterative rounds. This system doesn’t do any of that.”

Instead, Fastpass assigns each core its own time slot, and the core with the first slot scrolls through the complete list of pending transmission requests. Each time it comes across a pair of servers, neither of which has received an assignment, it schedules them for its slot. All other requests involving either the source or the destination are simply passed on to the next core, which repeats the process with the next time slot. Each core thus receives a slightly attenuated version of the list the previous core analyzed.

Bottom line

Today, to avoid latencies in their networks, most data center operators simply sink more money into them. Fastpass “would reduce the administrative cost and equipment costs and pain and suffering to provide good service to the users,” Balakrishnan says. “That allows you to satisfy many more users with the money you would have spent otherwise.”

Networks are typically evaluated according to two measures: latency, or the time a single packet of data takes to traverse the network, and throughput, or the total amount of data that can pass through the network in a given interval.

Original release: http://www.eurekalert.org/pub_releases/2014-07/miot-ndc071614.php

 

 

Filed Under: Components

Primary Sidebar

EE Training Center Classrooms

EE Classrooms

Featured Resources

  • EE World Online Learning Center
  • CUI Devices – CUI Insights Blog
  • EE Classroom: Power Delivery
  • EE Classroom: Building Automation
  • EE Classroom: Aerospace & Defense
  • EE Classroom: Grid Infrastructure
Search Millions of Parts from Thousands of Suppliers.

Search Now!
design fast globle

R&D World Podcasts

R&D 100 Episode 8
See More >

Current Digital Issue

June 2022 Special Edition: Test & Measurement Handbook

A frequency you can count on There are few constants in life, but what few there are might include death, taxes, and a U.S. grid frequency that doesn’t vary by more than ±0.5 Hz. However, the certainty of the grid frequency is coming into question, thanks to the rising percentage of renewable energy sources that…

Digital Edition Back Issues

Sponsored Content

New Enterprise Solutions for 112 Gbps PAM4 Applications in Development from I-PEX

Positioning in 5G NR – A look at the technology and related test aspects

Radar, NFC, UV Sensors, and Weather Kits are Some of the New RAKwireless Products for IoT

5G Connectors: Enabling the global 5G vision

Control EMI with I-PEX ZenShield™ Connectors

Speed-up time-to-tapeout with the Aprisa digital place-and-route system and Solido Characterization Suite

More Sponsored Content >>

RSS Current EDABoard.com discussions

  • 3.7v to 5v dc to dc boost converter
  • Thyristor - Reverse Diodes and Reverse Blocking
  • Calculation of FET switch ON time for Boost PFC?
  • Inverting Preamp schematic
  • Suitable Stackup required for a high current carrying PCB

RSS Current Electro-Tech-Online.com Discussions

  • looking for resistor for my treadmill.
  • alternate of 80386/486 microprocessor
  • Right channel distortion on vintage fisher rs-2010
  • Basic questions about MOSFETS, Gate Drivers and Diodes
  • Neon Transformers for sale

Oscilloscopes Product Finder

Footer

EE World Online

EE WORLD ONLINE NETWORK

  • 5G Technology World
  • Analog IC Tips
  • Battery Power Tips
  • Connector Tips
  • DesignFast
  • EDABoard Forums
  • Electro-Tech-Online Forums
  • Engineer's Garage
  • Microcontroller Tips
  • Power Electronic Tips
  • Sensor Tips
  • Test and Measurement Tips
  • Wire & Cable Tips

EE WORLD ONLINE

  • Subscribe to our newsletter
  • Lee's teardown videos
  • Advertise with us
  • Contact us
  • About Us
Follow us on TwitterAdd us on FacebookConnect with us on LinkedIn Follow us on YouTube Add us on Instagram

Copyright © 2022 · WTWH Media LLC and its licensors. All rights reserved.
The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media.

Privacy Policy