Content delivery networks (CDNs), generally speaking, have two configurations: push or pull. In a push CDN, content is pushed through a primary server to users, and origin pulls CDNs, allowing users to point content at the server to then pull it through and distribute across a network. Both architectures come with their advantages and disadvantages, and enterprises should choose the right CDN for their business needs accordingly.
Where CDNs differ greatly is their setup. Businesses can either centralize their CDN, designating one location for content origin, or they can create a multi-CDN architecture, distributing content delivery across multiple servers. There are benefits and drawbacks for either configuration and today we're examining the qualities of content distribution within a multi-CDN strategy.
What is Multi-CDN?
In order to fully understand a multi-CDN architecture, it's important to first understand what a CDN is. CDN stands for "content delivery network," which is a series of connected servers that deliver content across a network. These servers can have different geographical locations or have a central location.
A multi-CDN architecture is a type of server infrastructure that distributes content across multiple CDNs and edge servers located in different geographies. The geographical distribution of a multi-CDN strategy is significant because it is the key contributing factor to one of the biggest advantages of this distribution strategy: superior speed. As with anything, though, a multi-CDN network's power hinges on the effectiveness of its distribution and setup.
How is a Multi-CDN Architecture Implemented?
Implementing a content delivery environment of any scale requires the proper setup; for multi-CDNs in particular, the deployment method is critical for the effectiveness of the strategy.
Static CDN Method
A static CDN method stores files that do not change often. For example, most sites have numerous JavaScript and CSS files that only change when developers deploy updates to the site. These static files can be cached at the CDN for fast delivery to the reader's browser.
Ratio Load-Balancing
A ratio load-balancing method for multi-CDN integration, also known as weighted round-robin load-balancing, is a method that bases traffic loads on the administrator's configurable values. The administrator uses a value such as 1, 3, 5 and the CDN load balancer sends traffic to servers based on a ratio calculation of connections each server is currently handling.
Performance Load-Balancing
Another method for integrating a multi-CDN strategy is performance load-balancing. Performance load-balancing sends traffic to CDN servers based on their current performance statistics. For example, if CPU utilization is high, then a load balancer would send traffic to another server with less resource utilization.
Geolocation Load-Balancing
One main advantage of a CDN is its numerous geolocated data centers. As the name suggests, geolocation load-balancing determines which server will handle a request based on the user's geolocation data. Data transferred at closer distances will increase perceived performance and improve the user experience.
Benefits of Multi-CDN Strategy
As the demand for video and digital media streaming continues to grow globally, many content distributors will be forced to consider ways to optimize server infrastructure around speed. One of the many benefits of placing servers within a multi-CDN architecture is increased speed, but this isn't the only benefit. Additionally, multi-CDNs provide superior performance, capacity, and security in content distribution.
Benefit #1
The benefit of a multi-CDN strategy is performance. Performance is shown to affect the user experience, bounce rate, and customer retention. For any organization on a traditional hosting platform, adding a multi-CDN to infrastructure will immediately improve performance. CDNs cache content on fast servers, so users will get high-performance delivery of their requests.
Benefit #2
The second benefit is the elimination of a single point of failure. Should one CDN fail in production, the secondary failover CDN can take over until the original is brought back into service. Elimination of a single point of failure reduces downtime and can even keep production uptime at 100% with a well-designed infrastructure plan.
Benefit #3
For organizations with global customers, the multi-CDN architecture allows you to host servers in data centers across the globe. It offers faster performance to those customers in remote locations away from the local business host servers. Bringing data centers closer to the target customer reduces the distance the data must travel, which speeds up application performance.
Drawbacks of Multi-CDNs
While multi-CDNs have a lot of benefits in the world of digital streaming we live in today, of course, this content distribution strategy comes with its own set of drawbacks. The cost is much higher than working with a single CDN. The organization must work with a higher budget to manage multiple CDNs for one application.
The other disadvantage is its technical overhead. Administrators must be able to configure and manage the additional architecture. If they don't have the skillset to configure multiple CDNs, then the administrators must take the time to learn and configure settings.
Integrating with Google Cloud
According to Google, Cloud CDN is tightly integrated with Cloud Monitoring and Cloud Logging. -
They provide "detailed latency metrics out of the box, as well as raw HTTP request logs for deeper visibility. Logs can be exported into Cloud Storage and/or BigQuery for further analysis with just a few clicks. -
"As part of Google Cloud, Cloud CDN caches your content in 96 locations around the world and hands it off to 134 network edge locations, placing your content close to your users, usually within one network hop through their ISP. -
Read more at the Google blog, linked below.
Is a Multi-CDN Strategy right for you?
Every organization must weigh the pros and cons of a multi-CDN architecture strategy. This strategy can improve performance and reduce downtime, so an organization dependent on application uptime could leverage more pros than cons. As with any infrastructure change, even with performance enhancements, these benefits should be weighed against the additional costs to deploy multiple CDNs.
