CDN stands for Content Delivery Network. It can also be referred to as Content Distribution Network. CDN is a group of spatially distributed servers that increase the rate at which web content is delivered by making it more accessible to users.
In plain terms, CDN can be referred to as a group of Interconnected servers that facilitates the swift transfer of digital entities required for loading internet content such as JavaScript files, images, videos, HTML pages, etc. Presently, a significant portion of web traffic is served on CDN, signifying that the usefulness of CDN extends across various aspects.
How Does CDN Work?
The basic mode by which content delivery networks operate is by temporarily storing digital entities such as web pages, images, audio, and videos on proxy servers that are close to the users' physical locations. As a result, the users can seamlessly utilize these entities by uploading or downloading content, streaming videos, etc., without delay.
Content Delivery Networks utilize cache contents just like other data centers stationed globally. Caching is a process used by digital devices to store file copies temporarily. With the integration of the cache feature into Data centers, users can quickly access internet content from an internet-enabled device via a nearby server.
To achieve this, a CDN produces cached versions of its content. These cached versions must be stored on several servers at various geographical locations. These locations are referred to as Points of Presence ( PoP). Each PoP contains multiple servers that temporarily store contents and deliver these contents to users in a close range. This reduces the distance between the users and the web servers.
This implies that when a user in a country ( for instance, The United States Of America) intends to access a foreign website ( say The United Kingdom), it will be done via a local USA PoP. This reduces the time it takes to access web content and receive feedback.
What Are The Components of CDN?
Several technological entities come together to make an effective content delivery network. These are:
Media Library
A media library is a reservoir that stores contents. The contents from various CDN customers are contained in a media library. Media libraries are usually large file servers, and they are programmed to store contents only. Since media libraries do not deliver content, they support a limited number of simultaneous connections. An example of a media library is NetApp.
Media Servers
The contents contained in a media library are distributed to users or other caches by media servers. Since media servers perform the delivery functions, they are compatible with many simultaneous users.
Caching Servers
Caching servers perform a dual function. They can be used to store and, at the same time, share necessary web content with the users. Caching servers are distributed across the content delivery networks hierarchically. Hence, a CDN usually contains 2 or 3 cache tiers.
The first tier is the Origin tier. The origin tier entails the cache groups situated close to the media library.
After the Origin tier is the Mid-tier, the Mid-tier consists of cache groups deployed at the network's epicenter.
A third tier, called the Edge tier, may also be present. The Edge tier serves the users the contents in its cache.
Content Routing System
A content routing system directs the users to the relevant cache that contains the needed contents. The request initially goes to the content routing system when a user intends to access web content. Afterward, it is directed to the applicable cache in the network
Load Monitoring System
As the name implies, the load monitoring system regulates the amount of work done by the CDN. From time to time, the load monitoring system analyses the CDN's caches and media servers to monitor their status and service availability.
Logging Server
Logging servers do log collection, storage, and aggregation in a CDN. CDN networks generate hundreds of log messages per second. These log messages are system logs and service logs. System logs are generated when a notable event occurs in the network. Service logs are generated when there's a transaction on the network. CDN uses customized
logging servers and log aggregation servers to relieve the media delivery servers from logging operations.
Analytics Server
An analytics server in a CDN network provides real-time reports and historical reports. These are used to monitor the CDN network's activities and plan for necessary upgrades.
Network Operations Control (NOC) Portal
CDN administrators use a network operations control portal to oversee activities on a CDN network. This portal can be used to configure and maintain CDN network tools.
Digital Rights Management Server
For users to gain authorization into CDN networks, digital rights management servers must step in. DRM servers authorize the users of a CDN network before providing them with the content.
Why Do Businesses Need CDN?
CDN Improves Marketing Efficiency
When Content Distribution Networks are up and running, businesses can monitor the efficiency of their marketing strategies. This implies that businesses can keep a tab on their customers' experience and easily notify them of new deals, products, and discounts.
Furthermore, CDN provides businesses with an analysis of customers' data and shopping patterns. Hence, CDN augments a company's marketing strategy and, by implication, improves customer satisfaction.
CDN Provides Businesses With Real-Time Updates
This is particularly useful for media and publishing companies. One of the ways a media website is ranked is how fast it receives and disseminates information on real-time occurrences.
These companies need to deliver prompt and up-to-the-minute information. CDN comes in handy by helping these companies update their website home pages and headlines as they receive real-time updates.
CDN Regulates Server Load
Since CDN consists of servers that are widespread and these servers deliver cached contents, this implies that the entire contents are not stored on a single primary server. Strategically stationing servers across several distances makes each server less susceptible to overload. This is because CDN frees up additional capacities of the servers and enables it to serve a large number of users simultaneously seamlessly.
CDN Augments Website Security
By regulating the loads on web servers, content delivery networks effectively combat cyber-attacks that operate by causing traffic spikes on key servers, especially in DDoS(Distributed Denial Of Service) attacks. In these types of attacks, the attackers intend to crash a DNS server by overloading it with a hectic amount of requests. However, CDN mitigates these attacks by distributing these servers and storing a copy of the web contents on each server.
All of these point to the fact that the usefulness of CDN in the modern-day business world can not be overemphasized.
