An origin shield is a buffer between a CDN and the origin server used to protect the server from traffic spikes and potential downtime. It absorbs traffic and can improve performance by caching frequently accessed content. Many CDN providers offer origin shields as part of their services to improve the reliability and availability of their CDN.
In recent years, the use of content delivery networks (CDNs) has become increasingly popular in the realm of online video streaming. CDNs are used to deliver content quickly and efficiently to users across the globe. However, CDNs are not without their vulnerabilities.
One major issue is the potential for an overload of requests to be sent directly to the origin server, causing it to crash. This is where the concept of an “origin shield” comes into play.
In this blog post, we will explore the importance of origin shields in CDNs used for video streaming, what would happen without one, and which companies provide an origin shield for their CDN services.
What is a CDN?
To start off, let’s understand what a CDN is and then move onto talking about Origin Shields. Go here for a detailed explanation of how a CDN works.
A Content Delivery Network (CDN) plays a crucial role in delivering video, image, and website content across the world while maintaining optimal performance. Major streaming platforms like Netflix, Amazon Prime, HBO, and YouTube rely heavily on CDNs for their day-to-day operations to ensure high-quality service and cost-effectiveness.
A content delivery network (CDN) is a system of distributed servers that are deployed in multiple locations around the world. These servers are connected to the Internet and are used to store and deliver web content, such as HTML pages, images, and videos, to users based on their geographic location.
CDNs help to provide a superior user experience, delivering content efficiently and with minimal latency.
To enhance website speed and performance, a CDN distributes content across multiple servers in various geographic locations. By doing so, the CDN minimizes the distance data needs to travel between the user and the origin server, resulting in faster loading times. This is particularly beneficial for users accessing the website from remote locations far from the origin server.
Okay now that you have a fair idea of what a CDN is, let’s move on to understanding what an Origin Shield is.
What is an Origin Shield in CDNs?
An origin shield is a critical component of a Content Delivery Network (CDN) architecture that is used to protect the origin server from traffic spikes and to improve the overall performance of the CDN.
Without an origin shield, CDNs can experience problems such as thundering herds and request collapsing, which can have a significant impact on the performance and availability of the CDN.
To understand how an origin shield protects an origin server, let us first understand what Thundering Herds are.
A thundering herd is a scenario where a large number of requests are directed towards the same resource simultaneously, causing a surge of traffic to the origin server. This can occur when a popular video is released, or when there is a sudden increase in demand for a particular resource. Please read this article for a detailed understanding of Thundering Herds.
As the number of requests increases, the origin server can become overwhelmed, leading to poor performance (cache hit and hit ratios), increased latency, and potential downtime.
This can have a significant impact on the user experience, as users may experience slow loading times, buffering, or other issues.
Now that we know what a thundering herd is and the problems it can cause, it is simple to define what an Origin Shield is —
An origin shield is essentially a buffer between the CDN and the origin server. Its purpose is to absorb traffic and protect the origin server from being overwhelmed by requests. Without an origin shield, a sudden surge of requests could cause the origin server to crash, resulting in significant downtime and potential revenue loss for the content provider.
This can help prevent poor performance, latency, and potential downtime.
Additionally, an origin shield can help to improve the overall performance of the CDN by caching frequently accessed content. This can reduce the amount of traffic that needs to be sent to the origin server, ultimately improving the user experience for those accessing the content.
Why do we need an origin shield?
As we explained in the previous section, an origin shield is essentially a buffer between the CDN and the origin server. Its purpose is to absorb traffic and protect the origin server from being overwhelmed by requests (as can be seen in the Thundering Herd problem).
Without an origin shield, a sudden surge of requests could cause the origin server to crash, resulting in significant downtime and potential revenue loss for the content provider.
Additionally, an origin shield can help to improve the performance of the CDN by caching frequently accessed content. This can reduce the amount of traffic that needs to be sent to the origin server, ultimately improving the user experience for those accessing the content.
What would happen without an origin shield?
It is quite obvious, that without an origin shield, the origin server would be exposed to direct traffic from the CDN.
This could lead to a number of issues, including increased server load and potential downtime. Additionally, the origin server would be vulnerable to DDoS (distributed denial of service) attacks, which could further compromise its availability.
In a worst-case scenario, the origin server could become completely overwhelmed by the volume of traffic being directed towards it, resulting in a complete shutdown.
This would be catastrophic for the content provider, as it would result in extended downtime and significant revenue loss.
All these problems can be prevented to an extent by the use of an Origin Shield between the origin and CDN.
What are the advantages of using an Origin Shield?
n origin shield can have a significant impact on the performance of a CDN, improving a number of key metrics such as latency, throughput, and availability. Here are a few ways that an origin shield can help to improve CDN performance:
One of the primary benefits of an origin shield is that it can help to reduce latency. By caching frequently accessed content at the edge of the network, an origin shield can reduce the number of requests that need to be sent to the origin server, ultimately reducing the time it takes to access the content. This can result in faster page load times, improved user experience, and increased engagement.
An origin shield can also help to increase the throughput of the CDN by reducing the load on the origin server. By absorbing traffic spikes and preventing thundering herds, an origin shield can ensure that the origin server is not overwhelmed, allowing it to handle a higher volume of requests without experiencing downtime or performance issues.
An origin shield can also help to improve the availability of the CDN by providing a buffer between the CDN and the origin server. This can help to prevent request collapsing and other issues that can lead to downtime, ensuring that the content remains available to users at all times.
Reduced bandwidth costs:
By caching frequently accessed content at the edge of the network, an origin shield can also help to reduce bandwidth costs for the content provider. This is because less traffic needs to be sent to the origin server, ultimately reducing the amount of bandwidth required to deliver the content.
Finally, an origin shield can help to improve the scalability of the CDN by providing a buffer between the CDN and the origin server. This can help to absorb traffic spikes and ensure that the origin server is not overwhelmed, allowing the CDN to scale more efficiently and handle a higher volume of requests without experiencing performance issues.
Which companies provide an Origin Shield?
Fortunately, many CDN providers now offer origin shields as part of their services. Here are a few examples:
- Cloudflare: Cloudflare is one of the most popular CDN providers in the world, and they offer an origin shield as part of their service. Their Shielding service provides protection against DDoS attacks and other threats, while also providing improved performance and availability.
- Akamai: Akamai is another leading CDN provider that offers an origin shield as part of their service. Their Shield technology provides protection against DDoS attacks, while also improving the overall performance and reliability of their CDN.
- Amazon Web Services (AWS): AWS offers an origin shield as part of their CloudFront CDN service. Their Shield Advanced service provides protection against DDoS attacks, while also offering improved availability and performance.
In conclusion, the use of an origin shield is critical for CDNs used in video streaming.
Without an origin shield, the origin server would be vulnerable to traffic spikes, DDoS attacks, and potential downtime. Fortunately, many CDN providers now offer an origin shield as part of their services, including Cloudflare, Akamai, and AWS.
The implementation of an origin shield can provide significant benefits in terms of improved performance, reliability, and security. For content providers looking to ensure the highest level of availability and performance for their video streaming services, an origin shield is an essential component of their CDN strategy.
If you are interested in learning more about CDNs, check out these articles –
- How does a CDN work?
- What is the Thundering Herd Problem in CDNs? What is Request Collapsing?
- How does a Multi-CDN work?
- What is the advantage of using a CDN for Live Streaming?
- What is Cache Hit, Cache Miss, and TTL (Time-To-Live) in CDNs?
Krishna Rao Vijayanagar
Krishna Rao Vijayanagar, Ph.D. is the Editor-in-Chief of OTTVerse, a news portal covering technological and business news in the OTT space. With extensive experience in video compression, ABR streaming, video analytics, monetization, and more, Krishna has held multiple roles in R&D, Engineering, and Product ownership at companies such as Harmonic Inc., MediaMelon, and Airtel Digital. Krishna has published numerous articles and research papers on the latest trends in OTT and frequently speaks at industry events to share his insights and perspectives on the fundamentals and the future of OTT streaming.