Describes three methods of content distribution in CDN service configuration
Netflix is a content platform and production company with 231 million subscribers as of January 2023. To ensure a comfortable viewing experience, Netflix is introducing its own content delivery network (CDN), commonly known as “Netflix Open Connect,” deployed around the world.
CDN is an inseparable entity in sites that deliver video or audio, such as Netflix or YouTube. In this blog, we will introduce the structure, advantages, and disadvantages of CDN in an easy-to-understand manner.
index
Three ways to distribute content
CDN service configuration
Why is CDN service important?
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Three ways to distribute content
In content distribution, many network configurations use virtual machines, which can easily cope with the network load caused by concentrated access. We introduce network configurations and their advantages and disadvantages that shorten response time, which greatly affects user satisfaction.
☑︎ | Content transfer using virtual machines
☑︎ | object storage
☑︎｜CDN (Content Delivery Network)
Content delivery using virtual machines
A virtual machine (VM) refers to a computer created by a doctor using software on a computer. In content deployment, we see many configurations that use a combination of virtual machines and load balancers.
The configuration of multiple virtual machines with a load balancer provides the benefits of load balancing, scalability, and availability, making it ideal for dynamic content distribution.
The downside is that fees tend to be expensive and setup can be time consuming.
object storage
Object storage service is a service that can store and manage large amounts of data. Its advantage is that it is easy to handle capacity expansion and can be used inexpensively. It is used for things where robustness is important, such as videos, images, backups, and long-term archives.
The downside of object storage is that it requires know-how to maintain the quality of access speeds or can be cumbersome when scripting or file additions occur.
Content Delivery Network (CDN)
Object storage, which allows for the scalability of servers using virtual machines and the low-cost storage of large amounts of data such as video, is an essential foundation for video distribution.
On the other hand, the increased cost of scaling servers and the cost of maintaining speed quality when using object storage are major disadvantages for video transmission companies.
So, there is a CDN service to solve the shortcomings.
CDN service configuration
A CDN is a mechanism for distributing web content such as images and videos from a cache server closest to the user. A CDN consists of two elements:
☑︎ | origin server
☑︎ | Cache (edge) server
origin server
Points to the server that hosts the original files for the content. Origin servers include cloud services and on-premise servers. When the first user accesses or the cache is revoked, the origin server is accessed to retrieve the content.
Cache (Edge) Server
This is a server group consisting of cache (edge) servers installed around the world. When users browse content, the closest cache server distributes the content.
Cache is a mechanism that speeds up content delivery through a CDN. The first user's request will reach the origin server, but second and subsequent users will be served the first user's cached (accumulated in storage) data, allowing the page to be displayed faster.
By utilizing CDN, even platforms that deliver video on a large scale, such as Netflix, can distribute the load and achieve faster display speeds.
By balancing the load when access is concentrated, it prevents server downtime and prevents loss of purchasing opportunities and reduced sales on EC sites.
Why is CDN service important?
The use of dynamic content has become mainstream on websites these days, and in terms of entertainment, live delivery and video streaming services are becoming popular. In this bandwagon, more and more companies are adopting CDN because it can reduce speed delays.
☑︎ | Advantages and disadvantages of using CDN
☑︎ | Precautions when using CDN
Advantages and disadvantages of using CDN
CDN's caching feature eliminates the need to access the original server when accessing the same content again; it is delivered from a server close to the user. Therefore, there is the advantage of speeding up the display speed, but there are also the following advantages.
Advantages ① | Reduce data transfer costs
The amount of data transfer required to host a website tends to be expensive because the cost is added to the data flow rate. By introducing a CDN, you can reduce the amount of data transfer provided by the origin server and reduce server costs.
Advantages ② | Improved availability and redundancy
Heavy traffic and hardware failures, such as servers, can stop a website from functioning properly. CDNs, on the other hand, avoid these risks with their distributed configuration, handle more traffic than origin servers, and can withstand hardware failures.
Using a CDN has both advantages and disadvantages. Here we introduce the drawbacks associated with the cache mechanism.
Disadvantage ① | Caching incidents may occur due to configuration errors
If you set up your CDN incorrectly, it can cache and deliver data that shouldn't be cached. In past cases, personal information was leaked due to configuration mistakes, which had a significant impact on the company's credibility. CDN settings need to be checked regularly to prevent these cache incidents.
Disadvantages ② | Old data may be transferred
CDNs require a certain amount of time for changes made on the origin server to be reflected on the cache server. Old cached data may be passed to the cache server until it is reflected.
It may take time for changes to be reflected, and similarly, deletion may also take time depending on the CDN used. It is necessary to check the purge (delete) speed when introducing it in case content deletion is necessary.
Precautions when using CDN
CDN improves availability and redundancy, but not all availability and redundancy can be achieved by CDN alone. It is also necessary to secure the embeddedness of the origin server itself, which is responsible for content that the CDN does not deliver (for example, individual information for each user, etc.).
Therefore, it is important to build a more robust system configuration by improving the availability and redundancy of the origin server in combination with CDN.
≫≫ An easy-to-understand explanation of the advantages and disadvantages of CDN introduction!
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The video delivery service uses CDN to achieve high-speed viewing and high CX (customer experience value). There are many advantages to using a CDN, including reduced costs, improved availability, and redundancy.
While convenient, failure to properly set or check may result in an accident.
When considering the introduction or use of a CDN, we regularly check to ensure that the specifications are properly understood and the correct settings are made.