1. AKAMAI Content Delivery Services

2. Content Delivery Services
Outline
History/Evolution
What’s all about CDS?
Akamai Technologies
Things to look for in a CDS
Public Vs Private
References
Questions ???
Content Delivery Services

3. Content Delivery Services
History/Evolution
New Challenges of WWW
Overheads
E-Business Demands
Solution
Content Delivery Services

4. Content Delivery Services
New Challenges of WWW
WWW has evolved beyond simply displaying static webpages
New challenge of delivering pages quickly
Computing overhead associated with building personalized pages, increasing delays, failures
Content Delivery Services

5. Content Delivery Services
Overheads
Dynamic content creation places significant strain on traditional web architecture
Network overhead
-User requests are dispatched to appropriate modules to serve
Processing overhead
-Modules determine which data to fetch and present
Disk I/O
-Modules query the backend databases
Content Delivery Services

6. Content Delivery Services
E-Business Demands
Site experience and effectiveness
- Dynamic content
- Locally Personalization
- Download speeds
Site cost structure
- Investments
- Scalability
- Reliability
- Performance
- System management & Applications
Content Delivery Services

7. Content Delivery Services
Quick Overview
                                                                                                   
Content Delivery Services

8. Content Delivery Services
Quick Overview
Content Delivery Services

9. Content Delivery Services
Solution
Replicating content over a large number of distributed servers without relying on centralized servers
Content Delivery Services

10. Content Delivery Services
What’s all about CDS?
CDS uses multiple web servers(CDN) distributed across the world to deliver copies of your website content
CDN is made of following elements.
- Storage and Delivery nodes
- Central controller
- Central manager
- Request manager
- Central data store
Content Delivery Services

11. Content Delivery Services

12. Content Delivery Services
Advantages
Speed
- Dispatching the requests to the closest site
- avoids congestion,delays and increases speed
often 2x to 10x speed improvement
Reliability
- CDS site failure
- ISP’s server failure
typically 6x reliability improvement
Flash Crowd Protection
- Multiple high capacity cache servers
handle large surges in traffic
Content Delivery Services

13. Content Delivery Services
Akamai Technologies
About Akamai
Embedded Object Replication.
Edge Suite - Enhanced Performance.
Advantages of EdgeSuite
Enhanced DNS
Content Delivery Services

14. Content Delivery Services
About Akamai
Leading provider of secure, outsourced e-business infrastructure services and software.
Akamai's intelligent edge platform for content, streaming media, and application delivery comprises more than 13,500 servers within over 1,000 networks in 66 countries.
Developed a set of breakthrough algorithms for intelligently routing and replicating content over a large network of distributed servers.
Content Delivery Services

15. Embedded Object Replication
Global Hosting Networks. MIT
Network Smart Monitoring System System and method for optimized storage and retrieval of data on a distributed Network.
Content Delivery Services

16. Global Hosting Networks
A method for intelligently routing and replicating content over a large network of distributed servers. Without disrupting the content provider’s direct relationship with end user.
Base HTML document portion of a web page is served from the content provider’s site. While one or more embedded objects serviced from hosting server nearest to the end user.
Content Delivery Services

17. Content Delivery Services
Overview of GHN
Browser sends a request to provider web site. It receives the request in the same way as if GHN was not being implemented.
Textual part of the page is returned as would be under normal circumstances.
<IMG SRC= >
Changed to
<IMGSRC = >
                                                                                                   
Content Delivery Services

18. Content Delivery Services
Architecture of GHN
Content provider server Provides the base HTML document.
Hierarchy of DNS servers The top level DNS servers identify a low level DNS servers and redirects the request to them. The lowest level DNS server resolves the request to an IP address for an Hosting server.
Hosting servers at the edge serves the object to the client.
Content Delivery Services

19. Content Delivery Services
<IMGSRC = >
Content Delivery Services

20. Content Distribution and Replication
Copies distributed so that no server becomes overloaded.
Copies tend to be on same server with time.
That is, hosting servers do not have copies of all the objects in the provider server.
Buddy servers – Used to assume the hosting responsibilities of associated hosting server in the event of a failure condition.
Content Delivery Services

21. Content Delivery Services
Load Balancing
Embedded object requests are distributed .
Embedded object URL is modified by prepending a virtual server host name.
Modified URL includes a value generated by a hash function, used to distribute embedded objects.
URL includes a ‘finger print’ value for the embedded object. Value used to check if object is modified.
Content Delivery Services

22. Content Delivery Services
<IMGSRC = >
Virtual Server Host Name
Hash Value of Image.gif
This process is preferably performed offline, Whenever an object is updated.
Content Delivery Services

23. Content Delivery Services
Advantages
No disruption of Content Providers relationship with the user Accurate count of hits tailoring content – advertising.
Fault tolerant – Buddy servers.
Load balancing- Automatic content management.
End user never receives outdated or stale content.
Scalability, Flash crowd protection, bandwidth saving.
Control of Proprietary Databases and Confidential Information.
Content Delivery Services

24. EdgeSuite - Enhanced Performance
To fully realize
- performance,
- reliability,
- scalability
- return on investment
the content delivery must be applied across an entire site’s content not just the embedded objects.
EdgeSuite is the only service capable of providing content delivery’s benefits to all of a site’s content.
Content Delivery Services

25. How it works ?
                                        

26. Content Delivery Services
How it Works
Content Delivery Services

27. Content Delivery Services
esi
Content Delivery Services

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

29. Content Delivery Services
Traditionally…
A page, with the combination of cacheable and non-cacheable content, is NOT Cached!
ESI addresses this issue!
Content Delivery Services

30. Content Delivery Services
ESI
Edge Side Includes or ESI is a small markup language for edge level dynamic web content assembly
Not defining content cacheable or non-cacheable
Split the page up into fragments, and each fragment can be separately marked as cacheable/not-cacheable
The fragments don't just contain HTML -- they can also contain ESI tags, which are not sent to the client but rather interpreted by the caching/CDN servers
The caching servers use these tags to assemble the fragments into a single page, fetching the non-cacheable fragments every time but retrieving the cacheable fragments from their caches, and then sending the resulting fully assembled page to the client.
Content Delivery Services

31. Advantages of EdgeSuite
Faster and more reliability
attract and retain customers
Secure Content
uses Secure Sockets Layer
Digitized Downloads
Streaming Delivery
deliver media streams for on-demand viewing
Tiered Distribution
delivery of site’s content with tiered architecture
Site Fail over
Site mirroring
Disaster Recovery
Site Maintenance
Provide Popularity Reports
enable to tailor marketing spending dollars
Content Delivery Services

32. Content Delivery Services
Enhanced DNS
Distributed Network of DNS servers
DNS queries are always handled quickly and without fail.
Multiple Physical machines
Enhanced DNS global service backs each logical name server IP address with multiple physical machines that are located in several networks
Users are transparently directed to the topologically closest name server
Content Delivery Services

33. Things to look for in a CDS
Content Acceptability
Performance Verification
Network Architecture
Transparency
Notification Service
Log Files
Cost and Bandwidth
Content Delivery Services

34. Content Delivery Services
Leading Providers
SolidSpeed Networks
- small to medium sized businesses
- accelerates HTML and images
- doesn’t require changes to website content
- provides software to measure speed and availability of websites
- provides complete log files
- reasonable price based on number of hits
minimum $50/month and scales upward
Content Delivery Services

35. Leading Providers(contd..)
Digital Island
- medium to large companies
- accelerates HTML and images
- cost based on peak bandwidth
$18 per GB served with $1500/month minimum
Content Delivery Services

36. Leading Providers(contd..)
Akamai
- large company sites
- modifications to site content required
- Akamai provides tools to assist this process
- cost based on peak bandwidth
- starts at $2000 per megabit/sec served per month
- requires 12 month minimum contract
Content Delivery Services

37. Content Delivery Services
Public Vs Private
Features to be considered
- Level of Distribution
- Targeted customers
- Resources
cutting-edge data center
experienced staff that can handle design and maintenance
- Investment
Content Delivery Services

38. Content Delivery Services
References
Content Delivery Services