CDN (content delivery network)

 

What is a CDN?

A content delivery network (CDN) is a geographically dispersed group of servers that collaborate to deliver Internet content quickly.

A CDN enables the rapid transfer of assets required for loading Internet content, such as HTML pages, javascript files, stylesheets, images, and videos. CDN services are becoming increasingly popular, and the majority of web traffic is now served via CDNs, including traffic from major sites such as Facebook, Netflix, and Amazon.

What are the benefits of using a CDN?

1. Reducing bandwidth costs-The cost of bandwidth use for website hosting is a major expense for businesses. CDNs can reduce the quantity of data an origin server needs offer through caching and other improvements, lowering hosting costs for website owners.
2. Improving website security - A CDN may improve security by providing DDoS mitigation, improvements to security certificates, and other optimizations.
3. Increasing content availability and redundancy-Large quantities of traffic or hardware breakdowns might cause a website's usual operation to be disrupted. A CDN can manage more traffic and resist hardware failure better than multiple origin servers because of its dispersed nature.
4. Improving website load times-Visitors benefit from faster page loading times by distributing content closer to them via a nearby CDN server (among other optimizations). Because visitors are more likely to leave a slow-loading site, a CDN can reduce bounce rates and increase the amount of time visitors spend on the site. In other words, a faster website attracts more visitors who stay longer.

   

   
   

 What Challenges does CDN solve?

  

CDNs solve a number of challenges.

-Performance: CDNs are all about speed and fast content delivery. The way they achieve it is caching content all around the world and bring content as close as possible to the users. An end user will be routed to the next available point of presence (POP) based on IP Anycast ,GeoIPO and other technologies.

- Scalability: Traffic spikes can easily be managed with a CDN. For example a software update can require large amount of bandwidth in a short period of time. A few servers could not handle that but with a CDN the load will be leveraged.

- Availability: CDN are designed for best reliability. If a server goes down, requests will be automatically be routed to the next available server. The user will not notice anything.

- Cost: Managing and operating dozens of servers is a challenge. Companies often come to the point, where they need to focus on their core business and building their own content delivery network is not worth it.

- Security: CDNs often offer extra security features as well in order to offer extra protection

How a CDN Works?

To minimize the distance between the visitors and your website's server, a CDN stores a cached version of its content in multiple geographical locations (a.k.a., points of presence, or PoPs). Each PoP contains a number of caching servers responsible for content delivery to visitors within its proximity.

In essence, CDN puts your content in many places at once, providing superior coverage to your users. For example, when someone in London accesses your US-hosted website, it is done through a local UK PoP. This is much quicker than having the visitor's requests, and your responses, travel the full width of the Atlantic and back

How does a CDN improve website load times?

When it comes to websites loading content, users drop off quickly as a site slows down. CDN services can help to reduce load times in the following ways:

• 1-The globally distributed nature of a CDN means reduce distance between users and website resources. Instead of having to connect to wherever a website’s origin server may live, a CDN lets users connect to a geographically closer data center. Less travel time means faster service.
• 2-Hardware and software optimizations such as efficient load balancing and solid-state hard drives can help data reach the user faster.
• 3-CDNs can reduce the amount of data that’s transferred by reducing file sizes using tactics such as minification and file compression. Smaller file sizes mean quicker load times.
• 4-CDNs can also speed up sites which use TLS/SSL certificates by optimizing connection reuse and enabling TLS false start.