Understanding CDN For Complete Beginners
Understanding CDN For Complete Beginners is an article in Web Hosting Reviews, a professional web hosting article blog. You can read more articles at Web Hosting,the next article:Reasons A Custom SLA Contract Is Vital With Managed Hosting.
Tags: CDN, CDN hosting, uk cdn
A content delivery network or UK CDN is used so that data can be downloaded quickly and more effectively at a lower cost. The data is replicated on many different edge servers and when there is a request for content this is directed to the nearest available node. This means that less of the network will be used for the transfer of this data. When there is a high demand the content can also be accessed from many different nodes which reduces the strain on the network infrastructure.
CDN hosting is supplied by an application service provider (ASP) and can make use of existing infrastructure that is paid for as it is used. Telcom providers have also been introducing content delivery networks on their own infrastructure. There are also some providers that rely on peer-to-peer networks
A CDN is comprised of a network backbone that connects many different nodes or edge servers, redundant central servers and fallback servers. There could be thousands of different nodes and these are distributed so that they are as physically close to the end user as possible. Content is then duplicated on to many different edge servers so that it can be accessed from many different points.
The application software will route request for content to the server which is closest or which has higher availability. This means that less of the overall network is used which reduces the overall load on it. Downloads will be quicker and more stable but there will also be a lower costs if the network is paid for as it is used. The software also decides how the information is moved around as demands change.
When you need to deliver content that requires high bandwidth capability this is the ideal solution and it is used by online broadcasting and video download services. One of the big advantages is scalability. If there is very high demand the content can be accessed from multiple nodes and so the system won’t crash.
If the data were to be accessed from a central point then bandwidth would be limited to what the backbone network could carry. By placing this information on many different nodes near the end user the bandwidth is effectively multiplied for every added node. If there are 10 nodes which each carry 10Gbit/s then it would be possible to download 100Gbit/s.
Both static and dynamic websites can also make use of a CDN. The problem comes in when there are many different copies of these all over the web and then the main website gets updated. This has been addressed with the introduction of ESI or edge side includes that automatically update each cashed copy so that people always see the newest version of the site.
CDN also has other similarities to cloud networking apart from scalability. There is also a high level of redundancy and all your online information is effectively backed up multiple times. This might negate the need for additional online backup. If any part of the content delivery network were to go down request could be redirected to other parts of it so there would be high website availability.
Did you enjoy this post? Why not leave a comment below and continue the conversation, or subscribe to my feed and get articles like this delivered automatically to your feed reader.
Comments
No comments yet.
Sorry, the comment form is closed at this time.