Best DNS + CDN Provider Solutions and Examples for Redundancy

Psst. Want to know a secret? Do you want to know the key to how some domains stay online during widespread DNS or Cloud provider outages while others go dark? There’s really no mystery to it all. It all comes down to one simple, but vitally important detail:
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Redundancy.
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There you go. That’s the secret. Are you disappointed it’s not something more earth-shattering? You shouldn’t be. Redundancy is one of the most simple, effective, and cost-efficient ways of ensuring your website or application never suffers a provider-related outage.

What is DNS Redundancy?

There are many methods to achieve redundancy for your domain. Failover, for example, is an excellent redundant solution that should be included in any domain strategy. But the most foolproof way to avoid an outage is still shockingly underutilized—and that is to have a secondary DNS. Whether it’s from DNS resolution errors, a DDoS attack, or some other type of provider-related outage, having redundant DNS will keep your site online and save your company a ton of money in the long run.
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Now let’s take a look at the different types of Secondary DNS.

Traditional Secondary DNS

When using traditional Secondary DNS, you have two providers to handle your domain’s web traffic. Zone files from the primary host are automatically synchronized with the secondary server when updates or changes are made to the domain’s zone. This way, if one provider goes down, queries for your domain will be retried by the other DNS provider. With this configuration, users won’t experience any disruption in service if one of the providers has an outage. As a bonus, resolvers tend to prefer the fastest authoritative nameserver—fastest time to first byte (TTFB). This means if your secondary provider has faster speeds than the primary, the recursive resolver will often use the secondary authoritative nameserver to get an answer for its request—a win-win for your company and your customers.

Primary/Primary DNS

A Primary/Primary setup includes the same benefits as traditional Secondary DNS, except your domain will have two dedicated resources for resolving queries. One advantage to having a Primary/Primary configuration is that it often affords companies more advanced customization options via API calls. Similar to traditional Secondary DNS, Primary/Primary improves the overall speed and performance of your domain but takes it one step further. Your domain’s query resolution will also be more accurate. 

Did you know?: When you use Primary/Primary at Constellix, the “secondary” service is automatically updated via API calls. Unlike many other providers, changes are forwarded to the secondary any time a record is changed in the primary configuration.

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Using Multiple CDNs with a Management Solution

If your domain serves graphic- and video-heavy content, you are likely using a content delivery network (CDN). Due to the nature of the cloud environment, redundancy is needed here as well. Having more than one CDN provider works as a safeguard against CDN failures. Just as a secondary DNS setup, if one CDN fails, traffic can be diverted to or split between CDNs that are still operational.

For an even better experience, there are Multi-CDN management options that allow organizations to manage all of their CDNs in one place. For example, Constellix’s Multi-CDN solution not only helps with management but also monitors the performance of each CDN. If one experiences a failure, Constellix will automatically redirect traffic to healthy CDN resources until the failed endpoint is back online.

Solutions and Examples Real-World Use Cases For DNS and CDN Redundancy 

The long and growing outage history for both cloud and DNS providers is a perfect “use case” for redundancy. I could stop the blog right here, end of story. But the need for redundancy is so crucial in today’s marketplace, that I would be doing you a disservice.
Here are some real-world examples that make the case for redundancy:

DNS Provider Outages of 2020-2021:

A quick google search will reveal a long history of DNS and cloud-related outages. Here are a few examples that caused large regional and international outages recently.

• Akamai - June and July 2021
• AWS - May 2021
• Cloudflare - April, July 2020
• Dyn/Oracle - 2021
• Fastly - June 2021
• GoDaddy November 2020 
• Google - January, March, April, June, August 2020, April 2021
• Microsoft - February, March (2), May, June, September (2), October, November, April 2021
• Network Solutions - March, May 2021
• Neustar UltraDNS - May 2021
• Oracle Dyn - March 2021
  

The Hidden Costs of Outages

A single minute of downtime can cost some companies well over the amount it would cost to have two providers for their domain. It’s estimated that damages from outages exceed $5,600 per minute or $300,000 per hour. Enterprise-level organizations could lose millions. The lost sales or ad revenue is detrimental on its own, but you also have to include the cost of mitigation and slowed or stopped employee productivity if any internal systems are affected. And then there’s the hit to brand reputation—which has far-reaching effects.

Big Brands that Still Don’t Use Multiple DNS or CDN Providers for Redundancy

Just one DNS or CDN provider experiencing an outage can cause a massive internet blackout. This has been seen time and time again. Why? Because thousands of domains still aren’t following DNS best practices and forgo having a secondary provider. If they did, there wouldn’t be nearly as many large disruptions in online services and applications. For example, here is a list of some of the largest domains that still rely on a single provider:

I could keep going, but the list would be way too long and I think you get the point. There are some pretty big brands on this list too, some of which cause major issues for any business or individual that relies on them if their services are unavailable.

DNS Redundancy is the Key to Success in the Online Marketplace

The simple truth is, almost all outages could be prevented with redundancy. In addition to saving your organization money and help uphold its reputation, redundancy also benefits customers who use your services or buy your products. For mission-critical systems, this is even more important. Considering the ever-growing reliance on the internet at work and home, businesses have a responsibility to do everything within their power to keep their domains and applications accessible. There is no better or more cost-effective way of doing this than having redundancy at every point of failure.

If you found this useful, why not share it? If there’s a topic you’d like to know more about, reach out and let me know. I’d love to hear your thoughts!

Liked this? You might find these helpful:

The Complete History of AWS Outages

Protect Your Domain From Outages With Secondary DNS

The True Cost of Downtime for IT