Tips for Building a Successful Multi-CDN Strategy

By Mark Fieldhouse, general manager EMEA at NS1.

  • Thursday, 5th March 2020 Posted 4 years ago in by Phil Alsop

Enterprises who want full optimisation of their websites and applications can no longer rely on data centres or even single content delivery networks (CDNs). This is why, over the past few years, organisations with users in multiple locations, or sites and mobile apps with an abundance of dynamic content, have shifted to a multi-CDN strategy.

 

There are some obvious advantages. Reaching a worldwide audience, especially with users located in several disparate geographic regions, with reliably good performance is best accomplished by using multiple CDN providers. Other benefits include the option to reduce costs through flexible pricing schemes; eliminating the risks associated with single-points-of-failure that can take systems and services offline; and taking advantage of service agreements with multiple providers, which can reduce financial and technical exposure.

 

It’s not always easy to know where to start, or how to prioritise requirements. Enterprises need to budget accurately for what will be a major investment, and understand how they can ensure a healthy return. 

 

Research according to requirements

Enterprises should first assess their content delivery needs, which should be matched against the specialisation of multiple CDN providers, and the value propositions they offer, and if appropriate, seek insight from similar companies who have already trodden this path. They can share their experience with that provider and offer insight as to how that provider is meeting SLAs and supporting different types of content. Often, CDN providers will be willing to provide references.

 

Being aware of all the challenges being faced is important, so organisations should seek internal feedback from the IT team as well as user feedback on any negative issues they are experiencing. If performance is suffering in specific regions, a multi-CDN approach will provide some flexibility to negotiate in those areas.

 

An additional question to ask is what the content delivery needs will be moving forward. One CDN provider is often all that is required to support a startup’s audience, but as the organisation grows, so too will its audience and their demands for content delivery.

 

Identify where the audience is located

Enterprises should ask themselves whether they need a global CDN provider or a local specialist, or both. The answer depends on where the end users are located and the reliability and performance of CDNs in each region. The benefit of a multi-CDN strategy is that the providers can be selected to achieve specific objectives in specific locations. This provides enterprises with more flexibility and the reassurance that they are achieving the best global performance based on where the end users are located.

 

When selecting a secondary provider, they should consider that larger CDN vendors often have international services that can address basic redundancy needs and guarantee that applications continue to run if the primary provider experiences an outage. However, this can also come at a high price point and care should be taken to assess performance on a regional basis. If this seems inadequate, then it is worth considering vendors locally, who can provide a quality performance at a better price.

 

Getting the right insight

When it comes to selecting CDN vendors, it is advisable to have clear, measurable objectives that can be matched to the providers’ reporting and analysis capabilities. The options can differ greatly, so enterprises must be clear about what insight they need and how often they need it. Identifying the metrics that are important can be helpful in negotiating arrangements with providers and ensure that all internal needs are addressed. If the IT team wants reports on a real-time basis, rather than daily, or hourly, this will need to be determined in advance.

 

Take it for a test drive

Once a provider, or multiple providers have been selected, the next stage is to make sure they perform as promised. This requires enterprises to put in place some tests, and any trusted provider will be happy to support these. Don’t be persuaded by figures on average performance or uptime. It is essential for an enterprise to evaluate based on their own assets and application traffic in actual network conditions.

 

The best approach is to start off by directing a small percentage of traffic to the new CDN provider, and monitor performance over lengthy peak and off-peak periods. This provides a window through which the performance of the website or application can be assessed in a variety of different environments. This insight is helpful in contract negotiations and ensures SLAs can be confidently sustained.

 

If companies do decide that a multi-CDN strategy is right for them, they will also need to make smart decisions about how to route traffic between the different platforms. The best way to do this is by using Application Traffic Steering solutions from third parties. These can collect performance data from users in real-time so CDN routing decisions can be made based on latency, availability or cost, and can prevent traffic from traversing back and forth between CDNs which tends to deliver a poor user experience.

 

Implementing a multi-CDN strategy can bring cost and performance improvements, particularly for companies that are serving content internationally or expanding to new service areas, but success requires careful selection that matches the organisation’s needs to provider capabilities. This is best accomplished by considering feedback from internal teams and users, identifying the location of users and who can best serve specific regions, clearly outlining expectations for metrics and reporting structure, and then testing in advance. This upfront effort reduces risk and instills confidence in technology investments, enabling enterprise teams to custom build an effective content delivery strategy that will bolster performance and reliability worldwide.