1 / 45

eCommerce Technology 20-751 Web Content Delivery

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.

ronny
Download Presentation

eCommerce Technology 20-751 Web Content Delivery

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. eCommerce Technology20-751Web Content Delivery

  2. Outline • The importance of content • How is it delivered? • Content delivery networks • Peer-to-Peer Technologies • Napster, Gnutella, Freenet, Morpheus • Streaming

  3. The InternetLooks Simple on the Outside Content Providers End Users Internet SOURCE: CRAIG SNYDER

  4. UUNet NAP NTT NAP Inside – The 4 Bottlenecks 1. First Mile 2. Peering 3. Backbone 4. Last Mile UUNet NTT DeutscheTelekom SOURCE: CRAIG SNYDER

  5. 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

  6. 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

  7. .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

  8. 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

  9. 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

  10. 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

  11. 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

  12. Total page 87,550 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

  13. 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

  14. 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

  15. 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

  16. Akamai Distributing servers allows better handling of peak loads SOURCE: AKAMAI

  17. Current Installations Akamai Network Deployment 13000+Servers 1000+Networks 66+Countries

  18. Over 1300 Web Sites are Now Akamaized

  19. 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

  20. 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

  21. 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

  22. 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

  23. D E F B X? X? X X X? X? X? X? X? C Non-Indexed Search (e.g. Gnutella) A SOURCE: ARTURO CRESPO

  24. Non-Indexed Search • Advantages • Simple • Robust • Anonymous • Disadvantages • Performance • Network flooding • Anonymous

  25. X X X? C B D A Centralized Index Search (Napster) I X? SOURCE: ARTURO CRESPO

  26. Centralized Index Search • Advantages • Performance • Can be shut down • Disadvantage • Vulnerable to attack • Index node may become a bottleneck • Can be shut down

  27. Freenet: Chain Algorithm Darling, Tell me the truth! Believe me, I don’t have it. SOURCE: CHUN ZHANG

  28. Freenet C B D A But I know Joe may have it since I borrowed similar stuff him last time. I SOURCE: CHUN ZHANG

  29. Freenet Sorry, No C B A D A, Help me! I SOURCE: CHUN ZHANG

  30. Morpheus Supernode Architecture SN2 SN4 SN3 SN1 SOURCE: PAVEL ZASLAVSKY

  31. 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

  32. 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

  33. 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.)

  34. 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

  35. 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

  36. 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

  37. SMIL: Layout and Synchronization RealServer REQUEST .SMIFILE SOURCE: REALNETWORKS SMIL =SYNCHRONIZED MULTIMEDIA INTEGRATION LANGUAGE

  38. 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

  39. 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

  40. 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

  41. Catalog Management SOURCE: CARDONET

  42. Catalog Management cXBL = Common XML Business Library cXML = Commerce XML SOURCE: CARDONET

  43. Content Creation Tools • Authoring tools • FrontPage, Word • Graphic Tools • Paint, Illustrator • Animation • Flash • Virtual Reality Modeling Language (VRML) • Audio/Video

  44. Q A &

More Related