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

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

How the Web Works How the Web Works Akamais Services Akamais Services Technology Overview Technology Overview Technological Challenges Technological Challenges The Future The FutureOutline

Internet Content Providers End Users The Web: Simple on the Outside

NAP UUNet Qwest AOL Network Providers Content Providers End Users Peering Points But Problematic on the Inside

400 million potential users = huge infrastructure problem The First Mile Bottleneck Content Provider now has worldwide audience; centralization doesnt workContent Provider now has worldwide audience; centralization doesnt work

% of Network Traffic ISPs (7,000) 6% Worldcom The Problems with Peering The Internet consists of over 7000 networksThe Internet consists of over 7000 networks No single network controls a large % of access trafficbiggest has 6% shareNo single network controls a large % of access trafficbiggest has 6% share

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

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

The Akamai Solution Akamai Servers at Network Edge Content Providers End Users NAP

Akamais Network Deployment 13,500+ Servers 60+ Countries Hosting, Access, Backbones, Satellite & Broadband 1000+ Leading Carriers

Thousands of Websites Are Akamaized

Advantages FastFast -Content is served from locations near to end users ReliableReliable -No single point of failure -Automatic failover ScalableScalable -Master site no longer requires massive available bandwidth

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

Akamais Service Offerings FreeFlow: delivers objects (gifs, jpgs, etc.) and rich graphics to end users from the edge of the InternetFreeFlow: 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 reliabilityFreeFlow 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 callsAkamai 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 WebcastsAkamai Forum: enables businesses to produce live, interactive Webcasts

Speaker Support e.g. PowerPoint Indexed Program Schedule Live or On-Demand Streaming Video Dynamic Surveys & Profiling No special client software Akamai Forum Other Features: Ask a QuestionAsk a Question Live Audience Phone-inLive Audience Phone-in Viewer RegistrationViewer Registration E-mail promotionE-mail promotion Download SlidesDownload Slides Searchable ContentSearchable Content

Akamais Service Offerings FirstPoint: a global traffic management service for content providers with geographically distributed Web serversFirstPoint: a global traffic management service for content providers with geographically distributed Web servers EdgeScape: allows customization of content based on users geographic location and connection bandwidthEdgeScape: allows customization of content based on users geographic location and connection bandwidth Reporter and Traffic Analyzer: provide historical and real-time Web site usage dataReporter and Traffic Analyzer: provide historical and real-time Web site usage data

Traffic Analyzer: Real-time viewing of customer trafficReal-time viewing of customer traffic Reports geographic distribution of trafficReports geographic distribution of traffic Reporter: For viewing of historical logsFor viewing of historical logs Customized data-mining of customer trafficCustomized data-mining of customer traffic Reporter and Traffic Analyzer

Akamais Service Offerings ACS: storage management service that persistently stores content delivered to end users via Akamais networkACS: storage management service that persistently stores content delivered to end users via Akamais network Digital Parcel Service: a comprehensive digital distribution and rights management solutionDigital Parcel Service: a comprehensive digital distribution and rights management solution EdgeSuite: enables dynamic assembly of personalized content at Akamais edge serversEdgeSuite: enables dynamic assembly of personalized content at Akamais edge servers

How the Web Works How the Web Works Akamai Services Akamai Services The Future The Future Technology Overview Technology Overview Technological Challenges Technological ChallengesOutline

3 Customer Web Server DNS WWW.XYZ.COM 1 User enters www.xyz.comUser enters www.xyz.com Browser requests IP address for www.xyz.comBrowser requests IP address for www.xyz.com Browser requests embedded objectsBrowser requests embedded objects Customer Web server returns HTMLCustomer Web server returns HTML 10.10.123.8 2 Browser requests HTMLBrowser requests HTML DNS returns IP addressDNS returns IP address 4 7 6 Browser obtains IP address for domain of embedded objects for pageBrowser obtains IP address for domain of embedded objects for page Customers Web server returns embedded objectsCustomers Web server returns embedded objects 10.10.123.8 5 Downloading www.xyz.com The Old Way

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

Downloading www.xyz.com with Akamais EdgeSuite User enters www.xyz.comUser enters www.xyz.com Browser requests IP address for www.xyz.comBrowser requests IP address for www.xyz.com WWW.XYZ.COM 1 DNS Optimal Akamai server returns Akamaized HTMLOptimal Akamai server returns Akamaized HTML5 Browser requests HTMLBrowser requests HTML 3 Akamai server assembles page, contacting customer Web server if necessaryAkamai server assembles page, contacting customer Web server if necessary 4 Customer Web server DNS returns IP address of optimal Akamai serverDNS returns IP address of optimal Akamai server 2 Browser obtains IP address of optimal Akamai servers for embedded objectsBrowser obtains IP address of optimal Akamai servers for embedded objects 6 Browser obtains objects from optimal Akamai serversBrowser obtains objects from optimal Akamai servers 7

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

End User Finding the IP Address: The Akamai Way Akamai High-Level DNS Servers 10 g.akamai.net 1 Browsers Cache OS 2 Local Name Server 3 xyz.coms nameserver 6 www.xyz.com 7 a212.g.akamai.net 9 15.15.125.6 16 15 11 20.20.123.55 Akamai Low-Level DNS Servers 12 a212.g.akamai.net 30.30.123.5 13 14 4 xyz.com.net Root (InterNIC) 10.10.123.55 akamai.net8

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

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

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

Syntax Example Akamai Weather Forecast Similar to SSI so its easily understood but also breaks performance bottlenecks when distributed across 12,000 serversSimilar to SSI so its easily understood but also breaks performance bottlenecks when distributed across 12,000 servers Used as an API to third-party applications on Akamais networkUsed as an API to third-party applications on Akamais network

Connecting from the Edge to the Source Source Server End User

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

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

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

Technological Challenges Huge scaleHuge scale -Hundreds of millions of users -Tens of thousands of servers -Thousands of locations -Thousands of customers Must monitor Internet conditions & instantly respond to changesMust 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 costsMust 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 serviceMust tolerate large numbers of component failures without ever disrupting service Control algorithms must be distributed and work with imperfect informationControl algorithms must be distributed and work with imperfect information DNS responses must be given in millisecondsDNS responses must be given in milliseconds 1) Mapping and Server Assignment

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

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

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

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

BET.com BET.com Akamaized 90% of Each Web Page with FreeFlow: Improved site performance (6-10 times) Quadrupled page view capacity Postponed 2 nd data center build out Preserved graphic-rich page design Improved user experience Net first year benefits of $1.3 million 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

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