Cedexis: Pros and Cons of Cloud and Hybrid CDN Delivery

In the past year, cloud data centers have become almost ubiquitous across the globe—or at least in key markets—as high-performance, low-cost options for media delivery. But are they doing so at the expense of CDNs?

Cloud-hosted data centers have a role to play in media delivery, according to Pete Mastin, market strategist with Cedexis. But they also come with some limitations.

“As people moved to cloud infrastructures, they lost the visibility they were used to in the data center,” said Mastin.

Mastin discussed the business drivers for a hybrid CDN approach during a presentation called "Understanding Cloud & Hybrid CDN Strategies" at the Content Delivery Summit, held in conjunction with the Streaming Media East 2015 show in New York this week.

Mastin said Cedexis is well suited to provide insight in to the benefits of what he calls a hybrid CDN. The concept around a hybrid CDN is a content delivery environment in which an enterprise provides and manages some resources in-house but has other services provided externally from a traditional CDN.

Cedexis uses Real User Measurements (RUM) to collect billions of availability and performance measurements—from 3 billion to over 6 billion measurements on any given day—from many data networks around the world.

Based on this RUM data, the company can make real-time decisions around how to best utilize multiple CDNs or even a CDN in conjunction with an in-house origin, the latter forming the basis of a hybrid CDN.

Mastin pointed out several stages of growth from a single origin to a hybrid CDN in a chart. This "CDN Maturity Model" slide started with single origin, moved to a single CDN, through a multi-CDN approach, and ultimately matured as a hybrid-CDN approach.

He further explained the models, balancing between a multi-CDN solution and a hybrid CDN solution. Mastin says about half of the ten Cedexis clients use an occasional origin delivery model. 

Another model, used by fewer clients, uses a localized performance improvement approach, adding a cache in a particular underserved geography.

A final model, where points of presence at many locations are built out as a private CDN, uses the traditional CDN approach for peak performance.

Mastin said the use of these models by Cedexis clients shows how online media (website, media, video, advertising) companies are implementing these strategies. But the biggest future growth is coming in terms of hybrid CDNs.

“Why are hybrid CDN approaches becoming popular now?” asked Mastin. “First, the cost of delivery is increasing.”

“Second, web performance continues to be a differentiator for online businesses,” said Mastin “Video, e-commerce, and advertising-based models all compete on performance.”

Third, Mastin says, web caching has become a best practice, including the creation of reverse proxies to thwart denial-of-service attacks.

Mastin also covered scenarios in which a commercial CDN alone may not fit the business model.

Scaling, long-tail catalogs, hyper-regional audiences, significant security requirements, and highly dynamic applications are some of the issues that may compel companies to move away from a solely commercial CDN approach.

“Cost containment is the biggest factor,” added Mastin.

Finally, Mastin showed examples of clients that use a hybrid CDN approach.

The New Observer, a French-speaking newspaper, uses a hybrid approach, as does the well-known Michelin travel site, and both have moved towards hybrid buildout.

A third example, Virtual Expo, has moved from using only a CDN to a hybrid CDN approach, but recently settled on a purpose-built CDN, which is based primarily on the uses of Varnish boxes and Cedexis real-time analytics.