shot of network cables and servers in a technology data centerBad news. Customers and end-users are reporting that your organization’s web sites and applications are sluggish. Loading takes an unreasonably long time and your apps don’t respond quickly. You jump into triage mode to try to find the source of the problem.

But the problem is, everything looks fine on your end. Your sites and applications have been tested and proven to be well coded and fast, your server infrastructure has been optimized and tuned, and all of your dashboards and performance monitoring tools look good.

So if the problem isn’t anywhere in your infrastructure, where could it be? Surprisingly, the cause of your poor web performance may not be in your server room or network, in fact, it’s often completely out of your control.

Where could this be? Well, have you checked with your DNS provider?

It may seem a little weird that DNS would have an impact on your performance. After all, it basically just converts the web address the user enters in the browser (as in and points it at the actual IP address or name of your website or application. And for a long time, it was true that DNS didn’t impact performance all that much.

But many trends in web sites and applications have come about in recent years that have led to sluggish performance that can be linked directly to DNS.

One of the first and most common is the rise of modular web sites and applications. By building web content that consists of pieces from multiple sites and applications, businesses can take advantage of lots of great capabilities without having to start from scratch. However, loading this web content can mean having to resolve multiple DNS queries within a single page or application.

Another issue is web content that has too short of a TTL (time to live). It used to be that TTLs were set to hours or more, presenting very little impact on performance. Today, some web content will have TTLs set to seconds, meaning constant DNS lookups and adding the potential for increasing delays in resolving this web content.

Probably one of the most frustrating causes of poor DNS performance comes from something that many organizations do to improve web performance. Companies often turn to Content Delivery Network providers and Global Server Load Balancing (GSLB) services to increase performance by putting content closer to wherever customers and users are. However, this also results in the use of long CNAME addresses for this web content (meaning that when you type that single website URL, it actually resolves across several DNS point using very long address chains). This can result in DNS roundtrips that are triple what would normally be the case, adding lots of potential for slowed performance and users abandoning your web content.

Most organizations don’t think too much about their DNS, in fact, many just use whatever their ISP or Internet connectivity provider gives them. But you don’t have to be stuck with this. There are a growing number of third-party DNS providers that have the potential to address some of these issues and also provide increased DNS management capabilities.

In the end, when poor web performance raises its ugly head, remember that the problem may not be in your data center or web infrastructure. It just may be the DNS that is supposed to be sending users to the right place to access your content.

Read the Aberdeen report, Managing the High Demands of Today’s Workloads