how content delivery network works? (networking exam)

Oh man! Ad-blocking software has been detected! :'(

This website is run by the community, for the community... and it needs advertisements in order to keep running. Blocking our ads means your killing our stats!
Please disable your ad-block, or become a premium member to hide all advertisements and this notice.

I find it simple. Have a cdn edge server near user, cache the request and when next time he asks for it, give it.

But I am pretty sure what I am thinking although is correct, isn't complete and there is sth missing.

My book has just included some small benefits of CDN, that's all. But that too isn't given in detail with illustrations(although it is not necessary i feel).

Exam questions of mine has asked like how CDN reduces delay in received requested object for 8 marks(3hrs exam, 80 full marks).

The answer of this is literally 1 line ie definition of CDN. and maybe 2 figures showing how it works with and without CDN.

another question asked in exam is-:

how proxy CDN works, explain with example.

I am not sure how the updating of content happens. Does only 1 proxy server gets updated or all proxy servers get updated when 1 CDN brings a fresh copy of web page from origin server?

It is confusing and believe me the tutorials for this thing are literally advertisements of various CDNs. it is tiresome.

 

Oh man! Ad-blocking software has been detected! :'(

This website is run by the community, for the community... and it needs advertisements in order to keep running. Blocking our ads means your killing our stats!
Please disable your ad-block, or become a premium member to hide all advertisements and this notice.

CDN gets complicated for the site owner who has to make sure it caches the stuff they do want (static images and so on) but not things that change a lot.

There's two ways a CDN updates its cache that I know of (not a web dev). The main way is what you expect, when one person in Australia downloads a file from a server in the USA, the Aus cace keeps and holds a copy of that file for other Aussies for a day.

BUT, if you are the publisher of the site and you roll out a big update, you can pay the CDN provider to go and pre-emtively collect stuff to cache. Say you are a book publisher and you are about to annouce there is a new Harry Potter book - your web site is going to get beaten up immediately, so instead of auto scaling the web servers to infinity, you take the load off them in advance by pushing to Akamai or whoever.

For a simple networking exam, you definitely only need to use that first case though.