A Content Delivery Network (CDN) is a globally distributed network of servers or Points of Presence (PoP) whose purpose is to provide faster content delivery, content is replicated and stored throughout the CDN so users can access storage geographically away from the user The nearest location data. This differs from the traditional approach of storing content on only one central server, where clients access a copy of the data near the client, rather than all clients accessing the same central server to avoid bottlenecks near that server. What is a Content Delivery Network?
What is a Content Delivery Network used for?
CDNs are designed to optimize the delivery of web content, and some of the key advantages they offer companies and their users include:
Faster load times: Content cached by a CDN is geographically close to its users, reducing the travel distance required for requests and responses. As a result, users experience faster page load times, which can increase conversions and reduce bounce rates.
Reduced bandwidth costs: Serving all requested content from an origin server requires significant bandwidth and processing power at the origin server. A CDN reduces the load on the bandwidth and bandwidth requirements by caching static content and performing other optimizations, which can help reduce costs considerably.
Improved availability and redundancy: A reliance on a centralized infrastructure (such as serving all content from origin servers) increases the risk of downtime due to hardware failures, network outages, and other events, and CDNs distribute content and requests across multiple location, thereby reducing the impact of local outages.
Enhanced website security: In addition to optimizing access to web content, CDNs can also include security features. By preventing distributed denial-of-service (DDoS) attacks, enhancing digital certificate security, and other security controls, CDNs can reduce the probability and impact of cyberattacks.
CDN Architecture and Key Components
Below is a simple model of a content delivery network, with its key components and their roles explained below:
What is a Content Delivery Network?
Content Provider: The entity that delivers the content
Authorization: The content provider grants the CDN provider permission to deliver the content
Report: Content Providers Ask CDN Providers for Performance Analysis to Evaluate CDN Provider Service Quality and Access Other Relevant Data
Source: A copy of the content sent by the content provider
Content: Digital information created and/or licensed for distribution
Request: A user requests a content provider to view or store data (content) locally
Delivery: CDN delivers 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: With the primary purpose of delivering content to end users, a delivery node is a server containing a cache running one or more content delivery applications. They are usually located as close as possible to the end user. Content can be manually stored to these nodes (push CDN), or delivery nodes can request content from origin nodes based on cache expiration rules (pull CDN). The advantage of a push CDN is that the content is immediately available to the users who need it. Its main disadvantage is that the content provider has to actively “push” the content every time the content is updated. The advantage of a pull CDN is that it automatically requests content from content providers. Its main disadvantage is the initial speed of content delivery: when a user first needs content, the delivery speed will be the same as if the content provider had not used a CDN. However, after this initial request, all other users located in the same geographic location or in close proximity to the original requesting user will be able to access the content immediately as it will be cached within the Delivery Node.
Storage Node: The main purpose is to store a copy of the original data distributed to Delivery Nodes. Storage nodes can be deployed in a tiered model to allow tiered caching.
Origin Nodes: These are the primary sources of content that can be distributed throughout the network or within the content owner’s infrastructure.
Control node: The main purpose is to host the management, routing and monitoring components of the CDN.
main type of content
Dynamic content: Content dynamically generated by web servers using several common web programming languages such as php, ruby, or java
Static content: Content that typically doesn’t change very often and doesn’t need to be generated. Images, CSS and JavaScript, etc.
Streaming content: Video or audio files played through web browser controls.
