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The Challenges of Delivering Content on the Internet

The Challenges of Delivering Content on the Internet. Tom Leighton Chief Scientist Akamai Technologies. Outline. How the Web Works. Akamai’s Services. Technology Overview. Technological Challenges. The Future. The Web: Simple on the Outside…. Content Providers. End Users. Internet.

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The Challenges of Delivering Content on the Internet

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  1. The Challenges of Delivering Content on the Internet Tom Leighton Chief Scientist Akamai Technologies

  2. Outline How the Web Works Akamai’s Services Technology Overview Technological Challenges The Future

  3. The Web:Simple on the Outside… ContentProviders EndUsers Internet

  4. …But Problematic on the Inside Peering Points ContentProviders End Users Network Providers UUNet NAP Qwest NAP AOL

  5. The First Mile Bottleneck • Content Provider now has worldwide audience; centralization doesn’t work 400 million potential users = huge infrastructure problem

  6. The Problems with Peering • The Internet consists of over 7000 networks • No single network controls a large % of access traffic—biggest has 6% share 6% Worldcom % ofNetworkTraffic ISPs (7,000)

  7. The Problems with Peering (cont.) • Economic considerations limit peering capacity—results in loss of routes and congestion • Routing algorithms (BGP) ignore congestion! • Routing algorithms are also subject to accidental loss of routes (or introduction of incorrect routes)

  8. Bottleneck Implications • Slow downloads • Content must traverse multiple backbones and long distances • Unreliable performance • Content may be blocked by congestion or backbone peering problems • Not scalable • Usage limited by bandwidth available at master site • Inferior streaming quality • Packet loss, congestion, and narrow pipes degrade stream quality • Broadband doesn’t help • As broadband becomes ubiquitous, the disaster of centralized solutions becomes more obvious—not better

  9. Outline How the Web Works Akamai’s Services Technology Overview Technological Challenges The Future

  10. The Akamai Solution ContentProviders EndUsers Akamai Servers at Network Edge NAP NAP

  11. Akamai’s Network Deployment 13,500+ Servers 1000+ LeadingCarriers Hosting, Access, Backbones, Satellite & Broadband 60+ Countries

  12. Thousands of WebsitesAre Akamaized

  13. Advantages • Fast • Content is served from locations near to end users • Reliable • No single point of failure • Automatic failover • Scalable • Master site no longer requires massive available bandwidth

  14. Keynote Results Web Site Performance Typical Improvement with Akamai Noon May 16 Noon May 18 Noon May 22 Noon May 24 Noon May 15 Noon May 17 Noon May 19 Noon May 20 Noon May 21 Noon May 23 Noon May 25 Noon May 26 Noon May 27 Web object delivered without Akamai Web object delivered by Akamai

  15. Akamai’s Service Offerings • FreeFlow: delivers objects (gifs, jpgs, etc.) and rich graphics to end users from the edge of the Internet • FreeFlow Streaming: delivers streaming content to viewers worldwide with dramatic improvements in quality and reliability • Akamai Conference: a reseller offering that uses streaming media to extend the reach and functionality of ordinary conference calls • Akamai Forum: enables businesses to produce live, interactive Webcasts

  16. Akamai Forum No special client software Live or On-Demand Streaming Video Speaker Supporte.g. PowerPoint Other Features: • Ask a Question • Live Audience Phone-in • Viewer Registration • E-mail promotion • Download Slides • Searchable Content Dynamic Surveys & Profiling Indexed Program Schedule

  17. Akamai’s Service Offerings • FirstPoint: a global traffic management service for content providers with geographically distributed Web servers • EdgeScape: allows customization of content based on user’s geographic location and connection bandwidth • Reporter and Traffic Analyzer: provide historical and real-time Web site usage data

  18. Reporter and Traffic Analyzer • Reporter: • For viewing of historical logs • Customized data-mining of customer traffic • Traffic Analyzer: • Real-time viewing of customer traffic • Reports geographic distribution of traffic

  19. Akamai’s Service Offerings • ACS: storage management servicethat persistently stores content delivered to end users via Akamai’s network • Digital Parcel Service: a comprehensive digital distribution and rights management solution • EdgeSuite: enables dynamic assembly of personalized content at Akamai’s edge servers

  20. Outline How the Web Works Akamai’ Services Technology Overview Technological Challenges The Future

  21. DNS Customer Web Server 1 WWW.XYZ.COM 2 10.10.123.8 5 3 4 6 7 10.10.123.8 Downloading www.xyz.com —The Old Way • Browser obtains IP address for domain of embedded objects for page • User enters www.xyz.com • Browser requests IP address for www.xyz.com • Browser requests embedded objects • DNS returns IP address • Browser requests HTML • Customer’s Web server returns embedded objects • Customer Web server returns HTML

  22. .net Root(InterNIC) 4 5 TTL:1 Day Local Name Server 6 7 xyz.com DNS Servers TTL: 30 Minutes 8 3 10 1 2 Browser’s Cache 9 OS Finding the IP Address for www.xyz.com — The Old Way

  23. Customer Web server WWW.XYZ.COM DNS 1 2 6 5 7 4 3 Downloading www.xyz.com with Akamai’s EdgeSuite • User enters www.xyz.com • Optimal Akamai server returns Akamaized HTML • Browser requests IP address for www.xyz.com • Browser obtains IP address of optimal Akamai servers for embedded objects • DNS returns IP address of optimal Akamai server • Browser obtains objects from optimal Akamai servers • Browser requests HTML • Akamai server assembles page, contacting customer Web server if necessary

  24. Key Components • DNS Resolution: Finding the IP address for www.xyz.com • Page Assembly • Connecting from the edge to the source

  25. xyz.com 4 .net Root(InterNIC) 5 10.10.123.5 xyz.com’s nameserver akamai.net a212.g.akamai.net 8 7 9 6 15.15.125.6 www.xyz.com 10 g.akamai.net 11 20.20.123.55 Akamai High-Level DNS Servers 12 a212.g.akamai.net 13 Akamai Low-Level DNS Servers 30.30.123.5 Local Name Server 14 3 16 1 2 Browser’s Cache 15 OS Finding the IP Address:The Akamai Way End User

  26. DNS Maps & Time-To-Live TimeToLive • Maps created using info on: • Internet congestion • System loads • User demands • Server status • Maps are constantly recalculated: • Every few minutes for HLDNS • Every few seconds for LLDNS 1 day Root 30 min. HLDNS 30 sec. LLDNS TTL of DNS responses gets shorter further down the hierarchy

  27. Page Assembly Container Page[TTL=5d] Site owners create container pages that can be populated with varying content [XYZ news, content, promotions, etc. TTL=5d] [TTL=8h] [TTL=15m] [Breaking headlines TTL=2h]

  28. Page Assembly If gender = male and geography = New York then show article on NY Giants Sportswear EdgeSuite enables Web sites to build and deliver customizedcontent at theedge [XYZ news, content, promotions, etc. TTL=5d] [TTL=8h] [TTL=15m] [Breaking headlines TTL=2h]

  29. Syntax Example <html> <asi version = “1.0”> <head><title>Akamai Weather Forecast </title></head> <asi if= ”$geo == dc” include=”dcwthr.htm”/> <asi else-if= ”$geo == boston” include=”bostonwthr.htm”/> <asi else if = ”$geo == nyc “ include= “nycwthr.htm”/> <asi else == “ “ include= “uswthr.htm”/> </asi> </html> • Similar to SSI so it’s easily understood— but also breaks performance bottlenecks when distributed across 12,000 servers • Used as an API to third-party applications on Akamai’s network

  30. Connecting from the Edge to the Source End User Source Server

  31. X • Maintain path performance data so that the optimal path can be used to reach optimal customer location (Akarouting) Connecting from the Edge to the Source End User Source Server

  32. Connecting from the Edge to the Source End User • If site is unreachable, then retrieve authoritative default information from Akamai’s ACS service X Source Server AkamaiACS • Maintain path performance data so that the optimal path can be used to reach optimal customer location

  33. x 12 3 4 Satellite Downlink Satellite Uplink 1 2 3 4 1 2 3 4 X X X X 1 2 3 4 Entry Point Encoding x 12 3 4 Top-level reflectors Differences for Live Streaming Regions

  34. Outline How the Web Works Akamai’s Services Technology Overview Technological Challenges The Future

  35. Technological Challenges 1) Mapping and Server Assignment • Huge scale • Hundreds of millions of users • Tens of thousands of servers • Thousands of locations • Thousands of customers • Must monitor Internet conditions & instantly respond to changes • Internet congestion and failures are widespread and unpredictable • Must load balance widely varying kinds of traffic, optimize multiple kinds of resources, and minimize various costs • Must tolerate large numbers of component failures without ever disrupting service • Control algorithms must be distributed and work with imperfect information • DNS responses must be given in milliseconds

  36. Technological Challenges 2) Logging, Reporting, and Billing • Several billion hits per day and growing rapidly • Real-time reporting of data to customers with user profiling and customized data mining • Real-time monitoring of system for NOCC with meaningful alerts and performance metrics • Support for real-time SQL queries to the system

  37. Technological Challenges 3) Operations • Huge distributed network that cannot go down, despite frequent software changes and constant growth • System needs to be secure against attacks as well as buggy third-party software

  38. Technological Challenges 4) Content Freshness and Accuracy • Stale content can never be served • Fast correction procedures in case of customer errors • Allow flexibility and ease of customer control over content

  39. Technological Challenges 5) Management of Live Streaming and Webcasting • Information dispersal to handle packet loss • Automatic swapping on connections to improve performance • Support for interactive and personalized messaging; e.g., Q&A • Real-time data aggregation for polling, etc. • Synchronized delivery of audio, video, and slides

  40. Outline How the Web Works Akamai’s Services Technology Overview Technological Challenges The Future

  41. BET.com The Premier African-American Portal “On Monday our traffic doubled, so we added two new servers with no effect. Tuesday afternoon we called Akamai. Tuesday night we were Akamaized and instantly 6-10 times faster.” Craig Maccubbin CTO of BET.com • BET.com Akamaized 90% of Each Web Page with FreeFlow: • Improved site performance (6-10 times) • Quadrupled page view capacity • Postponed 2nd data center build out • Preserved graphic-rich page design • Improved user experience • Net first year benefits of $1.3 million

  42. Questions?

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