Drafting behind Akamai (travelocity-based detouring)

ABSTRACT

To enhance web browsing experiences, content distribution networks (CDNs) move web content "closer" to clients by caching copies of web objects on thousands of servers worldwide. Additionally, to minimize client download times, such systems perform extensive network and server measurements, and use them to redirect clients to different servers over short time scales. In this paper, we explore techniques for inferring and exploiting network measurements performed by the largest CDN, Akamai; our objective is to locate and utilize quality Internet paths without performing extensive path probing or monitoring.Our contributions are threefold. First, we conduct a broad measurement study of Akamai's CDN. We probe Akamai's network from 140 PlanetLab vantage points for two months. We find that Akamai redirection times, while slightly higher than advertised, are sufficiently low to be useful for network control. Second, we empirically show that Akamai redirections overwhelmingly correlate with network latencies on the paths between clients and the Akamai servers. Finally, we illustrate how large-scale overlay networks can exploit Akamai redirections to identify the best detouring nodes for one-hop source routing. Our research shows that in more than 50% of investigated scenarios, it is better to route through the nodes "recommended" by Akamai, than to use the direct paths. Because this is not the case for the rest of the scenarios, we develop lowoverhead pruning algorithms that avoid Akamai-driven paths when they are not beneficial.

REFERENCES

• 1: Akamai and loral cyberstar alliance. http://www.akamai.com/en/html/about/press/press123.html.
• 2: Kazaa. http://www.kazaa.com/.
• 3: Planetlab. http://www.planet-lab.org/.
• 4: Akamai. Akamai CDN. http://www.akamai.com.
• 5: David Andersen , Hari Balakrishnan , Frans Kaashoek , Robert Morris, Resilient overlay networks, Proceedings of the eighteenth ACM symposium on Operating systems principles, October 21-24, 2001, Banff, Alberta, Canada
• 6: D. Andersen, H. Balakrishnan, F. Kaashoek, and R. Rao. Improving web availability for clients with MONET. In NSDI, Boston, MA, May 2005.
• 7: C. Bornstein, T. Canfield, and G. Miller. Overlay routing networks (Akarouting), 2002. http://www-math.mit.edu/steng/18.996/lecture9.ps.
• 8: C. Bornstein, T. Canfield, G. Miller, and S. Rao. Optimal route selection in a content delivery network. US Patent Application 20020163882.
• 9: John Dilley , Bruce Maggs , Jay Parikh , Harald Prokop , Ramesh Sitaraman , Bill Weihl, Globally Distributed Content Delivery, IEEE Internet Computing, v.6 n.5, p.50-58, September 2002 [doi>10.1109/MIC.2002.1036038 ]
• 10: T. Fei, S. Tao, L. Gao, and R. Guerin. How to select a good alternate path in large peer-to-peer systems? In IEEE INFOCOM, Barcelona, Spain, April 2006.
• 11: S. Gadde, J. Chase, and M. Rabinovich. Web caching and content distribution: a view from the interior. In WCW, Boston, MA, June 2000.
• 12: P. Gilmore. OARtech, 2001. http://www.osc.edu/oarnet/oartech/presents/oarnet/11apr2001.ppt.
• 13: K. Gummadi, H. Madhyastha, S. Gribble, H. Levy, and D. Wetherall. Improving the reliability of Internet paths with one-hop source routing. In USENIX OSDI, San Francisco, CA, December 2004.
• 14: Krishna P. Gummadi , Stefan Saroiu , Steven D. Gribble, King: estimating latency between arbitrary internet end hosts, Proceedings of the 2nd ACM SIGCOMM Workshop on Internet measurment, November 06-08, 2002, Marseille, France [doi>10.1145/637201.637203]
• 15: A. Habib and J. Chuang. A measurement-based analysis of residential multihoming. In IEEE INFOCOM, poster session, Miami, FL, March 2005.
• 16: K. Johnson, J. Carr, M. Day, and M. Kaashoek. The measured performance of content distribution networks. In WCW, Lisbon, Portugal, May 2000.
• 17: Jaeyeon Jung , Emil Sit , Hari Balakrishnan , Robert Morris, DNS performance and the effectiveness of caching, IEEE/ACM Transactions on Networking (TON), v.10 n.5, p.589-603, October 2002 [doi>10.1109/TNET.2002.803905]
• 18: J. Kangasharju, K. Ross, and J. Roberts. Performance evaluation of redirection schemes in content distribution networks. Computer Communications, 24(2):207--214, February 2001.
• 19: M. Koletsou and G. Voelker. The Medusa proxy: A tool for exploring user-perceived web performance. In WCW, Boston, MA, June 2001.
• 20: Balachander Krishnamurthy , Craig E. Wills, Analyzing factors that influence end-to-end Web performance, Proceedings of the 9th international World Wide Web conference on Computer networks : the international journal of computer and telecommunications netowrking, p.17-32, June 2000, Amsterdam, The Netherlands
• 21: Balachander Krishnamurthy , Craig Wills , Yin Zhang, On the use and performance of content distribution networks, Proceedings of the 1st ACM SIGCOMM Workshop on Internet Measurement, November 01-02, 2001, San Francisco, California, USA [doi>10.1145/505202.505224]
• 22: F. Leighton and D. Lewin. Global hosting system. US Patent No. 6,108,703.
• 23: LimeLight Networks. Limelight networks CDN. http://www.limelightnetworks.com.
• 24: R. Mahajan. How Akamai works? http://www.cs.washington.edu/homes/ratul/akamai.html.
• 25: Zhuoqing Morley Mao , Charles D. Cranor , Fred Douglis , Michael Rabinovich , Oliver Spatscheck , Jia Wang, A Precise and Efficient Evaluation of the Proximity Between Web Clients and Their Local DNS Servers, Proceedings of the General Track: 2002 USENIX Annual Technical Conference, p.229-242, June 10-15, 2002
• 26: Alberto Medina , Mark Allman , Sally Floyd, Measuring the evolution of transport protocols in the internet, ACM SIGCOMM Computer Communication Review, v.35 n.2, April 2005 [doi>10.1145/1064413.1064418]
• 27: Mirror Image. Mirror image CDN. http://www.mirror-image.net.
• 28: Akihiro Nakao , Larry Peterson , Andy Bavier, A routing underlay for overlay networks, Proceedings of the 2003 conference on Applications, technologies, architectures, and protocols for computer communications, August 25-29, 2003, Karlsruhe, Germany [doi>10.1145/863955.863958]
• 29: North American Network Operators' Group. NANOG mailing list. http://www.nanog.org/mailinglist.html, 1999, 2000.
• 30: Jitendra Padhye , Victor Firoiu , Donald F. Towsley , James F. Kurose, Modeling TCP Reno performance: a simple model and its empirical validation, IEEE/ACM Transactions on Networking (TON), v.8 n.2, p.133-145, April 2000 [doi>10.1109/90.842137]
• 31: Stefan Saroiu , Krishna P. Gummadi , Richard J. Dunn , Steven D. Gribble , Henry M. Levy, An analysis of internet content delivery systems, Proceedings of the 5th symposium on Operating systems design and implementation

  Due to copyright restrictions we are not able to make the PDFs for this conference available for downloading

  , December 09-11, 2002, Boston, Massachusetts [doi>10.1145/1060289.1060319]
• 32: S. Savage. Sting: a TCP-based measurement tool. In USENIX Annual Technical Conference, Boulder, CO, October 1999.
• 33: Stefan Savage , Andy Collins , Eric Hoffman , John Snell , Thomas Anderson, The end-to-end effects of Internet path selection, Proceedings of the conference on Applications, technologies, architectures, and protocols for computer communication, p.289-299, August 30-September 03, 1999, Cambridge, Massachusetts, United States
• 34: SAVVIS. Digital island CDN. http://www.savvis.net.
• 35: A. Shaikh, R. Tewari, and M. Agrawal. On the effectiveness of DNS-based server selection. In IEEE INFOCOM, Anchorage, AK, April 2001.
• 36: C. Tang and P. K. McKinley. A distributed multipath computation framework for overlay network applications. Technical Report MSU-CSE-04-18, Michigan State University, May 2004.

INDEX TERMS

Primary Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS
      C.2.2 Network Protocols

Additional Classification:
  C. Computer Systems Organization
  C.4 PERFORMANCE OF SYSTEMS
      Subjects: Measurement techniques

General Terms:
Experimentation, Measurement, Performance

Keywords:
Akamai, CDN, DNS, edge server, measurement reuse, one-hop, source routing