Ecommerce technology 20 751 web content delivery
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eCommerce Technology 20-751 Web Content Delivery. Outline. The importance of content How is it delivered? Content delivery networks Peer-to-Peer Technologies Napster, Gnutella, Freenet, Morpheus Streaming. The Internet Looks Simple on the Outside. Content Providers. End Users. Internet.

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eCommerce Technology 20-751 Web Content Delivery

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Ecommerce technology 20 751 web content delivery

eCommerce Technology20-751Web Content Delivery


Outline

Outline

  • The importance of content

  • How is it delivered?

    • Content delivery networks

  • Peer-to-Peer Technologies

    • Napster, Gnutella, Freenet, Morpheus

  • Streaming


The internet looks simple on the outside

The InternetLooks Simple on the Outside

Content Providers

End Users

Internet

SOURCE: CRAIG SNYDER


Inside the 4 bottlenecks

UUNet

NAP

NTT

NAP

Inside – The 4 Bottlenecks

1. First Mile

2. Peering

3. Backbone

4. Last Mile

UUNet

NTT

DeutscheTelekom

SOURCE: CRAIG SNYDER


Html title page for www xyz com with embedded objects

HTML Title Page for www.xyz.comwith Embedded Objects

<html>

<head>

<title>Welcome to xyz.com!</title>

</head>

<body>

<img src=“

<img src=“

<h1>Welcome to our Web site!</h1>

<a href=“page2.html”>Click here to enter</a>

</body>

</html>

http://www.xyz.com/logos/logo.gif”>

http://www.xyz.com/jpgs/navbar1.jpg”>

SOURCE: BRUCE MAGGS


Downloading www xyz com before akamai

DNS

Content Provider’s Web Server

2

10.10.123.8

5

3

4

6

7

10.10.123.8

Downloading www.xyz.com - before Akamai

1

WWW.XYZ.COM

  • Browser obtains IP addresses for hostnames listed in URLs of objects embedded on 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

  • Content provider’s web server returns embedded objects

  • Content provider’s web server returns HTML

SOURCE: BRUCE MAGGS


Dns resolution

.com .net

Root(ICANN)

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

DNS Resolution

SOURCE: BRUCE MAGGS


Problems with the centralized approach

Problems with the Centralized Approach

  • Slow

    • content must traverse multiple backbones and long distances

  • Unreliable

    • delivery may be prevented 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

SOURCE: BRUCE MAGGS


The akamai solution

The Akamai Solution

  • Monitors the Internet and routes around trouble spots

  • Distributes all forms of content and supports applications

  • Provides feedback on hit counts to content providers

SOURCE: BRUCE MAGGS


Downloading www xyz com the akamai way

DNS

Content Provider’s Web Server

1

5

WWW.XYZ.COM

2

3

4

6

Downloading www.xyz.com - The Akamai way

  • Content provider’s web server returns page with Akamaized URLs

  • User enters www.xyz.com

  • Browser obtains IP address of optimal Akamai server for embedded objects

  • Browser requests IP address for www.xyz.com

  • DNS returns IP address

  • Browser obtains objects from optimal Akamai server

  • Browser requests HTML

SOURCE: BRUCE MAGGS


Content delivery using akamai

Embedded URLs are Converted to ARLs

ak

Content Delivery Using Akamai

<html>

<head>

<title>Welcome to xyz.com!</title>

</head>

<body>

<img src=“

<img src=“

<h1>Welcome to our Web site!</h1>

<a href=“page2.html”>Click here to enter</a>

</body>

</html>

http://www.xyz.com/logos/logo.gif”>

http://www.xyz.com/jpgs/navbar1.jpg”>

SOURCE: BRUCE MAGGS


Typical page content

Total page87,550 bytesTotal Akamai Served 68,756 bytes

Banner Ads 16,174 bytes

Logos 3,395 bytes

Gif links 22,395 bytes

Navigation Bar9,674 bytes

Fresh Content17,118 bytes

78%

Page Served by Akamai

Typical Page Content

SOURCE: BRUCE MAGGS


Akamai dns resolution

xyz.com

.com .net

Root(ICANN)

4

5

10.10.123.5

xyz.com’s nameserver

akamai.net

a212.g.akamai.net

8

7

9

6

15.15.125.6

ak.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

Akamai DNS Resolution

End User

SOURCE: BRUCE MAGGS


Dns maps time to live

DNS Maps & Time-To-Live

TimeToLive

  • Map creation is based on measurements of:

    • 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

SOURCE: BRUCE MAGGS


Advantages of the akamai solution

Advantages of the Akamai Solution

  • Fast

    • Content is served from locations near to end users

  • Reliable

    • No single point of failure

    • Automatic fail-over

  • Scalable

    • Master site no longer requires massive available bandwidth

SOURCE: BRUCE MAGGS


Akamai

Akamai

Distributing servers allows better handling of peak loads

SOURCE: AKAMAI


Akamai network deployment

Current Installations

Akamai Network Deployment

13000+Servers

1000+Networks

66+Countries


Over 1300 web sites are now akamaized

Over 1300 Web Sites are Now Akamaized


Anatomy of a network

Cross-Internet

connections

Premises

Network

Internet Backbone

Local Loop

Anatomy of a Network

Origin Server Scalability,

Speed of Light

Peering Point

Congestion

Available

Bandwidth

“Middle Mile”

“Last Mile”

T1, DSL,

Cable Modem

Dial-up

Peering Capacity,

ISP Network Capacity

10 Mb to 1 Gb

Ethernet

Gigabit Optical

Network

SOURCE: CISCO


Content network building blocks

Content Delivery Services

Streaming

Applications

Web Hosting

E-Commerce

Content Delivery Networks

Content

Edge-Delivery

Content

Routing

Content

Switching

Content Distribution

& Management

Intelligent Network Services

L2/L3 Networks

Highly available, scalable, performance network at Layer 2/3

DSL

ISDN/Dial

Mobile

Fixed

Wireless

Cable

Dedicated/

ATM/FR

Content Network Building Blocks

L2 = DATA LINK LAYER

L3 = NETWORK LAYER

SOURCE: CISCO


Content delivery map

Content

Distribution

Manager

CDM

Origin Web Server

Content Delivery Map

Primary Data Center

Distributed Data Center

Content Edge Delivery

Content Distribution

Content Routing

Content Switching

Content Edge-Delivery

Content Delivery Node

Content Delivery Node

Local DNS Server

User Community

Content Router

Content Switching

SOURCE: CISCO


Peer to peer content delivery

Peer-to-Peer Content Delivery

  • Idea: store content at individual nodes instead of in one central place

    • Similar to Akamai

  • Problem: discovery (searching)

  • How do we find the content?

  • Unexpected effect

    • Clients and servers can be anonymous and untraceable


Non indexed search e g gnutella

D

E

F

B

X?

X?

X

X

X?

X?

X?

X?

X?

C

Non-Indexed Search (e.g. Gnutella)

A

SOURCE: ARTURO CRESPO


Non indexed search

Non-Indexed Search

  • Advantages

    • Simple

    • Robust

    • Anonymous

  • Disadvantages

    • Performance

    • Network flooding

    • Anonymous


Centralized index search napster

X

X

X?

C

B

D

A

Centralized Index Search (Napster)

I

X?

SOURCE: ARTURO CRESPO


Centralized index search

Centralized Index Search

  • Advantages

    • Performance

    • Can be shut down

  • Disadvantage

    • Vulnerable to attack

    • Index node may become a bottleneck

    • Can be shut down


Ecommerce technology 20 751 web content delivery

Freenet: Chain Algorithm

Darling, Tell me the truth!

Believe me, I don’t have it.

SOURCE: CHUN ZHANG


Ecommerce technology 20 751 web content delivery

Freenet

C

B

D

A

But I know Joe may have it since I borrowed similar stuff him last time.

I

SOURCE: CHUN ZHANG


Ecommerce technology 20 751 web content delivery

Freenet

Sorry, No

C

B

A

D

A, Help me!

I

SOURCE: CHUN ZHANG


Morpheus supernode architecture

Morpheus Supernode Architecture

SN2

SN4

SN3

SN1

SOURCE: PAVEL ZASLAVSKY


Morpheus query with fast stream

Morpheus Query with Fast Stream

56.78.79.5

SN2

SN3

SN1

234.67.8.9

123.5.78.9

234.67.8.9

56.78.79.5

123.5.78.9

SOURCE: PAVEL ZASLAVSKY


Content addressable networks

fish(dolphin, shark)

animal

Insect(ant, fly)

Content-Addressable Networks

  • Build a distributed directory similar to DNS by observing queries and their answers

fish(dolphin, shark)

Insect(ant, fly)

SOURCE: HAIYONG WANG


Delivering video

Delivering Video

  • Uncompressed video

    • 640 x 480 resolution

    • 24-bit color = 7.37 megabits/frame

    • 30 frames per second = 210 megabits/sec.

    • 1920 x 1080 = 1.5 Gbps

  • Compressed video

    • MPEG-2. Broadcast quality. 15 Mbps

    • AVI, QuickTime. 500 Kbps

    • RealNetworks. Designed for network speeds.20-200 Kbps. (At 20 Kbps, compression factor is greater than 10,000.)


Streaming

Streaming

  • Begin delivering content without full download

    • Lower latency

    • Low client storage requirement

    • Can start streaming at any point (not necessarily beginning

    • Live streaming possible (real-time compression)

  • Disadvantages

    • Lower quality, also affected by network connection

    • More time needed to compress

    • Need special server


True streaming

pnm

METAFILE

pnm

METAFILE

True Streaming

1.

USER REQUESTS

STREAMING MEDIA

4.

BROWSER

INVOKES

PLUG-IN

2.

BROWSER

with video

plug-in

BROWSER

REQUESTS

pnm

METAFILE

REALPLAYER

PLUG-IN

PLUG-IN

REQUESTS

STREAM

5.

STREAM

CLIENT SIDE

SERVER SIDE

3.

6.

REALSERVER

UPLOADS

STREAM

SERVER

UPLOADS

METAFILE

WEB SERVER

REALSERVER

pnm

METAFILE

STREAM


How streaming works

Web page is on an HTTP server

User visits a web page. Page contains a link to a metafile on the web server.

Metafile causes the player to launch and passes to it the path of the media server and media file.

Player connects to the media server and requests the file.

Media server streams file to the users player for viewing.

Media file is on a media server

How Streaming Works

WWW server

End users

Media server


Ecommerce technology 20 751 web content delivery

SMIL: Layout and Synchronization

RealServer

REQUEST .SMIFILE

SOURCE: REALNETWORKS

SMIL =SYNCHRONIZED MULTIMEDIA INTEGRATION LANGUAGE


Ecommerce technology 20 751 web content delivery

SMIL: Layout and Synchronization

RealServer

REQUEST .SMIFILE

(0,0)

376

video region

news region

184

(0,144)

ticker region

<head><layout>

<root-layout height="184" width=”376" background-color="black"/>

<region id="video" left="0" top="0" height="144" width="176" z-index="1"/>

<region id="news" left="176" top="0" height="144" width=”200" z-index="1"/>

<region id="ticker" left="0" top="144" height="40" width=”376" z-index="1"/>

</layout></head>

SOURCE: REALNETWORKS


Ecommerce technology 20 751 web content delivery

SMIL: Layout and synchronization (3/3)

RealServer

REQUEST .SMIFILE

(0,0)

376

video region

video.rm

news region

newstext.rt

184

(0,144)

ticker region

tickertext.rt

<body><par>

<video id="the_video" src="rtsp://media.real.com/video.rm" region="video"/>

<text id="the_news" src="rtsp://media.real.com/newstext.rt" region="news"/>

<text id="the_ticker" src="rtsp://media.real.com/tickertext.rt" region="ticker"/>

</par></body>

SOURCE: REALNETWORKS


Content creation delivery needs

Content Creation/Delivery Needs

  • Localized content

    • geography & language-specific pages

  • Personalization

  • Streamlined content

  • Wireless content

  • Match content richness to line speed

  • Animation

  • Software, file downloads

  • Compression


Catalog management

Catalog Management

SOURCE: CARDONET


Catalog management1

Catalog Management

cXBL = Common XML Business Library

cXML = Commerce XML

SOURCE: CARDONET


Content creation tools

Content Creation Tools

  • Authoring tools

    • FrontPage, Word

  • Graphic Tools

    • Paint, Illustrator

  • Animation

    • Flash

    • Virtual Reality Modeling Language (VRML)

  • Audio/Video


Ecommerce technology 20 751 web content delivery

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