What’s a multi-CDN?
A Content Delivery Network is a system of geographically dispersed servers that facilitates the delivery of digital content with high performance and high availability
By leveraging the right combination of CDN providers you can simultaneously improve end-user quality of experience while lowering costs
Redundancy, the ability to scale to meet large traffic demands and expand globally has never been more important for companies, from content publishers to ed-tech platforms, app discovery platforms, and even sports organisations, especially in an increasingly digital economy where online users’ patience is at an all-time low and churn rate translates to missed opportunities for brands.
Evidently so, IDC recently found that 68.7 per cent of enterprises view application delivery services as relevant to their organisation’s edge strategy with 75 per cent of these enterprises expecting less than five ms latency.
As such, how can organisations minimise latency or sluggish site movements to deliver an optimal user experience in the modern digital era?
One solution is to implement a multi-CDN strategy.
What’s a multi-CDN?
A Content Delivery Network is a system of geographically dispersed servers that facilitates the delivery of digital content with high performance and high availability. The idea behind a CDN is to move content much closer to end users.
Instead of centralising digital content, such as web applications, web objects, files, downloadable media and streaming media, on a relatively small number of servers, the content is cached across many servers distributed around the globe.
End-users now retrieve the content they’re looking for from the closest Content Delivery Network edge server, rather than going all the way back to the origin to retrieve it. A website empowered by a CDN can see up to 30 per cent more organic traffic, 200 per cent higher conversions, 60 per cent lower bounce rates, and a 40 per cent lift in revenue.
A CDN can also instantly create a TV broadcast-quality experience while converting live streams on-the-fly into the right device formats. This results in much better performance (lower latency) for your customers. It also avoids overloading your origin and allows your audience to scale.
What are the benefits of a multi-CDN?
There are several reasons to consider a multi-CDN strategy:
Availability
While an outage may not rise to the level of global notoriety, it’s likely just as devastating for your business. As the Internet has become more critical to every aspect of business, minutes of downtime can impact your bottom line and damage customer relationships. Multi-CDN can minimise single points of failure by providing alternate delivery options in the event of an outage.
Performance
Whether delivering online video, web content, or software over the Internet, poor performance results in abandonment, customer frustration and a negative impact on your brand. It’s unlikely that any single CDN delivers the best performance for all traffic types, in all regions, all of the time.
By intelligently balancing your content delivery needs across multiple CDN providers, you can mitigate the impact of the performance glitches of specific providers, in specific regions, for specific traffic types.
Capacity
Large-scale content delivery events may create choke points in individual CDN providers or in certain locations. Multi-CDN alleviates these bottlenecks by distributing the data load amongst multiple CDNs rather than from a centralised location.
For large live events such as the Olympics, rapid scaling is a critical function of CDNs. If a match is tied near the end of regulation time, there are usually massive spikes with fans logging in to watch the final minutes.
Security
Internet security is an increasing concern globally. In fact, cybercrime represents the fastest growing cause of data centre outages. If a CDN is compromised it could negatively impact the ability of customers trying to access your digital content or their experience in accessing that content.
Having multiple CDN providers allows you to minimise exposure, or bypass compromised CDNs altogether, in the event of a cyberattack.
Is Multi-CDN right for you?
Multi-CDN has some compelling benefits, but it is not necessarily for everyone. Ask yourself these questions when considering if a multi-CDN strategy is right for you.
What is the impact of an outage on your business? Can you afford minutes or hours of downtime? The less tolerant your business is of an outage, the more advantageous a multi-CDN strategy will be
How much traffic does your digital content generate? Do you exceed usage limits or have traffic spikes that could be alleviated with an overflow capability to other CDNs? The more traffic, the greater potential benefit derives from multiple CDNs.
How performance-sensitive are your digital content delivery needs? Performance is really important in some applications, e.g. video streaming, but may not be as important in others, e.g. downloading software patches. Multi-CDN is likely to have greater benefits in performance-sensitive cases.
How big is your audience and where are they located? The larger, and more distributed the audience, the greater the need for multiple CDNs.
How is content being stored? Is your digital content stored in the CDN or outside of it? Storing your content in the CDN should result in performance and cost benefits, but it will mean replicating your content when using multiple CDNs or picking a CDN that allows origin access from other CDNs.
How will you switch traffic between multiple CDNs? There are a number of methods as previously discussed, but which makes the most sense for your business? Do you have the time to manage manual DNS approaches, or the expertise to tune performance methods?
What performance metrics are most important for your business? Does the performance-based switching solution you’re considering support the metrics most important to your specific content delivery application, e.g. rebuffer ratios, bit rate, availability, throughput, and response time?
How many CDNs will you deploy? There is a point of diminishing returns as more CDNs are added. Adding CDNs introduces a measure of complexity because each CDN has its own user interface, set of APIs, billing methodology, functional capabilities etc. Your development and operations teams will need to understand and manage these differences. Is your audience distributed across the globe?
If your answer is yes to these questions, multi-CDN may be most beneficial to your organisation.
Selecting the right CDN partner
Once you have determined that adding a CDN to your content delivery environment makes sense, the next question becomes which partner to select. Here are some important factors to consider:
Geographic coverage
Important questions to consider: where are your users located? Where are you looking to expand? Look for a partner that has a presence in the regions or countries where most of your users are located. When considering your global traffic distribution, it’s also important to think about future growth.
If you expect to see increased traffic coming from emerging markets like India for example, a factor that into your decision now to avoid having to renegotiate your CDN contract or prematurely move CDN providers. Look for a partner that has a presence in places where most of your current and future users are located.
Performance metrics
Performance is a complex topic because it’s unique to different content delivery environments and workloads. It is fundamental to take into consideration the types of content you’re delivering and what performance metrics are most important to your customers’ experience.
Performance measurement
There are several performance monitoring tools commercially available, however, in many cases, results can be misleading. The best approach to evaluate performance is to do a trial or proof of concept with one or more CDNs, using your actual workload in the geographical regions that are most important to you.
Service and support
In times of need, excellent customer support can make all the difference. Consider how important it is for you to have access to live customer support. Will that support be available outside of business hours? What kind of support is offered in your region? Is the support free or is there a premium charged for this service? If you deliver live events what relevant experience does the partner have and are they willing to participate on a bridge before or during the event? Is the CDN vendor able to assist with onboarding or migrating from another CDN?
Content storage
Choices about content storage have a direct impact on workflow, total cost, and access speed. Poorly integrated storage can make it much more difficult to manage a large content library. You will have to consider whether there is a need to offload your content origin to a CDN and if so, how important is the performance of the CDN storage or mid-tier cache solution? Does the CDN storage solution support multi-CDN environments, and if so, how will the CDN storage solution you select to operate in a multi-CDN environment?
Final thoughts
Using multiple CDNs to deliver these digital content experiences promises even greater levels of availability and performance. By leveraging the right combination of providers, and enterprises you can simultaneously improve end-user quality of experience while lowering costs.
Source: e27
