Download - Global Internet Content Delivery Akamai Technologies and Carnegie Mellon University Bruce Maggs
Global Internet Content Global Internet Content DeliveryDelivery
Akamai TechnologiesAkamai Technologies
and and
Carnegie Mellon UniversityCarnegie Mellon University
Bruce Maggs
NAP
NAP
UUNetUUNet
QwestQwest
AOLAOL
Network Providers
ContentProviders
EndUsers
PeeringPoints
……But Problematic on the InsideBut Problematic on the Inside
The Akamai SolutionThe Akamai SolutionAkamai Serversat Network Edge
ContentProviders
EndUsers
NAP
NAP
Current Installations
Network Deployment Network Deployment
13000+Servers
1000+Networks
65+Countries
Content Delivery Using AkamaiContent Delivery Using Akamai
<html><html><head><head><title>Welcome to xyz.com!</title><title>Welcome to xyz.com!</title></head></head><body><body><img src=“<img src=“<img src=“ <img src=“ <h1>Welcome to our Web site!</h1><h1>Welcome to our Web site!</h1><a href=“page2.html”>Click here to enter</a><a href=“page2.html”>Click here to enter</a></body></body></html></html>
http://www.xyz.com/logos/logo.gifhttp://www.xyz.com/logos/logo.gif”>”>http://www.xyz.com/jpgs/navbar1.jpghttp://www.xyz.com/jpgs/navbar1.jpg”>”>
Embedded URLs are Converted to ARLsEmbedded URLs are Converted to ARLs
akak
Page Served by Akamai78%78%
Typical Page ContentTypical Page Content
Total pageTotal page 87,550 bytes87,550 bytesTotal Akamai ServedTotal Akamai Served 68,756 bytes 68,756 bytes
Navigation BarNavigation Bar9,674 bytes9,674 bytes
Banner Ads Banner Ads 16,174 bytes 16,174 bytesLogosLogos
3,395 bytes3,395 bytes
Gif linksGif links 22,395 bytes 22,395 bytes
Fresh ContentFresh Content17,118 bytes17,118 bytes
End User
Akamai DNS ResolutionAkamai DNS Resolution
Akamai High-Level DNS Servers
10g.akamai.net
1
Browser’s Cache
OS
2
Local Name Server
3
xyz.com’s nameserver
66ak.xyz.comak.xyz.com
77a212.g.akamai.net
9915.15.125.6
16
15
1120.20.123.55
Akamai Low-Level DNS Servers
12 a212.g.akamai.net
30.30.123.5 13
14
4 xyz.comxyz.com .com .net Root
(InterNIC)10.10.123.555
akamai.net
88
select cluster
select servers within cluster
Over 1300 Web Over 1300 Web Sites are Now AkamaizedSites are Now Akamaized
Regions
Differences for Live StreamingDifferences for Live Streaming
1 2 3 41 2 3 4
11 22 3 3 44x
1 2 1 2 33 4 4
1 2 3 41 2 3 4X X X X
11 22 3 4 3 4x
SatelliteDownlink
Entry Point
SatelliteUplink
Top-level reflectors
Encoding
Page AssemblyPage 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]
Syntax ExampleSyntax 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 Similar to SSI so it’s easily it’s easily understood— but understood— but also breaks also breaks performance performance bottlenecks when bottlenecks when distributed across distributed across 12,000 servers12,000 servers
• Used as an API to Used as an API to third-party third-party applications on applications on Akamai’s networkAkamai’s network
Connecting from the Edge Connecting from the Edge to the Sourceto the Source
Source Server
End User
• Maintain path performance data so that the Maintain path performance data so that the optimal path can be used to reach optimal optimal path can be used to reach optimal customer location (Akarouting)customer location (Akarouting)
X
Traffic Analyzer:Traffic Analyzer:
• Real-time viewing Real-time viewing of customer trafficof customer traffic
• Reports geographic Reports geographic distribution of trafficdistribution of traffic
Real-Time Reporting and AnalysisReal-Time Reporting and Analysis
Traffic Reporter:Traffic Reporter:
• For viewing of For viewing of historical logshistorical logs
• Customized Customized data-mining of data-mining of customer trafficcustomer traffic
Historical ReportingHistorical Reporting
9/11 Summary9/11 Summary
• Akamai’s network had capacity for all Akamai’s network had capacity for all content providers requesting servicecontent providers requesting service
• Total bits served on September 11 Total bits served on September 11 was approximately 3.5 times normalwas approximately 3.5 times normal
• Traffic was higher on September 12Traffic was higher on September 12
• (But not as high as January 7, 2002)(But not as high as January 7, 2002)
Network UtilizationNetwork Utilization
No affect on Network Egress (TX backbone example)
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09/10/01 09/11/01
09/10/01 09/11/01
The Reason Why ….The Reason Why ….
Akamai Server Interfaces
1. Original request sent to website2. Redirect to akamai server within POP3. Minimizes egress transit and improves overall performance
“AKAMAIZED” SITESC-SPAN go NetworkCBS ChicagoSunTimesCNN Interactive WashingtonPostCNET ReutersMSNBC YahooNBC Internet
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09/10/01 09/11/01
09/10/01 09/11/01
09/10/01 09/11/01
Engineering MethodologyEngineering Methodology
•C programming language (gcc).
•Reliance on open-source code.
•Automated unit and system builds and tests.
•Staged rollout to production.
•Independent release management.
•Burn-in on “invisible” system.
Research Questions (Hard)Research Questions (Hard)
• How do you know that new How do you know that new software for a distributed system software for a distributed system of tens of thousands of servers of tens of thousands of servers will work when it is deployed?will work when it is deployed?
• How do you even know if a system How do you even know if a system of tens of thousands of servers is of tens of thousands of servers is behaving properly?behaving properly?
• How do you know when such a How do you know when such a system is under attack?system is under attack?