Accelerate Your Website with CDN

Content Delivery Network (CDN) is a globally distributed Web server or Point of Presence (PoP) network. Its primary purpose is to speed up the speed when the users opened the website.

Generally, the content of the website is copied and then distributed to the entire CDN. Therefore, users can access the copied content on the server closest to their location, and significantly reducing the delay caused by optical cable transmission! This is very different from the old way of putting all data on a cloud server. It can also prevent DDoS to a certain extent. In other words, the client accesses the content on the closest server, and the transmission is completed exceptionally quickly!

High content loading speed also means a positive user experience. If all data is located on a central server, the user experience will be negatively affected by the limited loading speed. The longer the distance between the two objects in the communication, the longer it takes the content reaches any of these objects.

CDN's main purpose is to improve user experience and provide it with more effective network resource utilization. Content providers such as media companies and e-commerce providers pay CDN operators to offer their content to their audiences (ie, end-users). On the other hand, CDNs pay ISPs, operators, and network operators to host servers in their data centers. There are two fundamental mechanisms to explain the function of CDN:

1. Distribute important content to multiple globally distributed data centers to make it closer to the end-user, thereby speeding up downloading speed.

2. Use content type-based server optimization to provide the content to users most effectively.

3. For better performance, CDN can also offload the traffic provided directly from the content provider's original infrastructure, saving costs for the content provider. They are also very effective against DDoS attacks because they provide their own extensive distributed server infrastructure to absorb the attack volume.

4. Location is the key to content delivery speed. The farther the user is from the server (where the content is stored), the longer it takes for the content to reach the user, which will negatively impact the user experience.

CDN Architecture

The following graph is a simple model of a content delivery network: 

Content provider: The entity that provides the content

Authorization: the Content Provider gives the CDN Provider permission to deliver content

Report: The content provider requires the CDN provider to perform performance analysis to evaluate the quality of the CDN provider’s service and access other relevant data

Source: A copy of the content sent by the content provider

Content: Digital information created and licensed for distribution

Request: The user requests the content provider to view or store data (content) locally

Delivery: CDN provides the content to users

User: An entity requesting data (content) from a content provider

Most CDN architectures are designed using the following key components:

Delivery node: The primary purpose is to provide content to end-users. The delivery node is a server that contains a cache that runs one or more content delivery applications. They are usually as close as possible to the end-user. The content can be manually stored to these nodes (ex: Push CDN), or the delivery node can request content from the source node according to cache expiration rules (Pull CDN). 

The advantage of a Push CDN is that the content is immediately available to users who need it. On the other side, the disadvantage is that content providers must actively "Push" content every time it is updated. 

The advantage of Pull CDN is that it automatically requires content providers to provide content.

However, its disadvantage is the initial content delivery speed: when the user needs the content for the first time, the delivery speed is the same as when the content provider does not use the CDN. After this initial request, all other users located in the same geographic location or close to the original user who made the request will immediately access the content because it will be cached in the delivery node.

Storage node: The primary purpose is to store a copy of the original data being distributed to the delivery node. Storage nodes can be deployed in a hierarchical model to allow hierarchical caching.

Source nodes: These are the main sources of content and can be distributed throughout the network or the content owner’s infrastructure.

Source nodes: These are the main sources of content and can be distributed throughout the network or the content owner’s infrastructure.

Model of CDN Architecture

Advantages include decreasing bandwidth costs, shortening page load times, or improving the global availability of content. The number of nodes and servers that make up a CDN varies according to the architecture. Some of which have thousands of nodes on many remote points of presence (PoP). The others have thousands of servers. Others have established a global network and have a small number of geographic PoPs.

Three Main Types of Content:

Dynamic content: The web server uses several common web programming languages ​​(such as PHP, Ruby ​​, or java) to generate content dynamically.

Static content: Content that does not usually change frequently and does not need to be generated. Images, CSS, JavaScript, etc.

Streaming media content: video or audio files played through the Web browser controls.

No comments

Comment

Your email address will not be disclosed. The required fields are marked with*.

Related recommendation

No related articles!

微信扫一扫,分享到朋友圈

Accelerate Your Website with CDN