The Challenges of Delivering Content on the Internet Tom
Leighton Chief Scientist Akamai Technologies
Slide 2
How the Web Works How the Web Works Akamais Services Akamais
Services Technology Overview Technology Overview Technological
Challenges Technological Challenges The Future The
FutureOutline
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Internet Content Providers End Users The Web: Simple on the
Outside
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NAP UUNet Qwest AOL Network Providers Content Providers End
Users Peering Points But Problematic on the Inside
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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
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% 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
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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)
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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
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How the Web Works How the Web Works Akamais Services Akamais
Services Technology Overview Technology Overview Technological
Challenges Technological Challenges The Future The
FutureOutline
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The Akamai Solution Akamai Servers at Network Edge Content
Providers End Users NAP
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Akamais Network Deployment 13,500+ Servers 60+ Countries
Hosting, Access, Backbones, Satellite & Broadband 1000+ Leading
Carriers
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Thousands of Websites Are Akamaized
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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
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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
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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
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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
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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
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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
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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
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How the Web Works How the Web Works Akamai Services Akamai
Services The Future The Future Technology Overview Technology
Overview Technological Challenges Technological
ChallengesOutline
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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
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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
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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
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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
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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
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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
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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]
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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]
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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
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Connecting from the Edge to the Source Source Server End
User
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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
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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
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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
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How the Web Works How the Web Works Akamais Services Akamais
Services Technology Overview Technology Overview Technological
Challenges Technological Challenges The Future The
FutureOutline
Slide 35
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
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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
Slide 37
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
Slide 38
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
Slide 39
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
Slide 40
How the Web Works How the Web Works Akamais Services Akamais
Services Technology Overview Technology Overview Technological
Challenges Technological Challenges The Future The
FutureOutline
Slide 41
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