Data Center Geodiversity: Does It Matter?

February 7, 2019
Colocation, Disaster Recovery, Hybrid IT

blue storm, geodiversity for colocation

Written by Justin Ellison, Inside Solution Architect

Despite headlines that read “The Data Center is Dead,” data centers aren’t going anywhere any time soon. Even as more companies move to the cloud, the cloud has to live somewhere. That somewhere is on physical servers in a data center.

Plus, many companies find colocation as a good first step toward moving to the cloud. Others find it beneficial to adopt a hybrid IT strategy that combines cloud and colocation to best meet their needs. Whatever their rationale, businesses are going to continue to need colocation facilities.

But if you need a colocation facility, how do you determine which one will best meet your needs? One of the criteria that many colocation providers like to promote is “geodiversity.”

The idea is that the provider offers data centers in locations that are a specific distance apart. Does that really matter? Our answer to that at US Signal is: it depends. 

Understanding Geodiversity

Geodiversity — short for geographic diversity — in the context of data centers refers to the distance between two or more facilities. It typically is used when talking about disaster recovery (DR). The idea is that you want to maintain adequate distance between your primary and backup sites.

But your backup site won’t do you much good if it gets taken out by a tornado or flood that also takes out your primary site. That’s one of the main reasons to ensure your primary and backup sites are far enough part so as not to be affected by various kinds of disasters.

Even sites with redundant power can fail if back-up power supplies eventually give out. Others that are still operational may be inaccessible due to blocked roads and transportation system breakdowns that occur because of disasters. Only data centers with geodiverse configurations can keep businesses running.

Of course, there are different opinions as to how much distance should be between data centers. Some industry experts recommend 60-100 miles. Others recommend a minimum of 200 miles. It really depends on your business requirements and the kinds of disasters that may be most likely to occur in the areas in which your facilities are located.

For example, if you’re in a hurricane-prone area, a greater distance may be needed between two data centers because these types of events can affect large geographic areas.

The Non-disaster Variables

Specific use cases and applications will also drive the acceptable distance between data centers. Keep in mind that adding distance and networking devices between two points increases the latency between them. Some applications may require low latency to perform acceptably for supporting user experience, but others may perform acceptably at higher latency.

In addition, distance between two data centers isn’t always even a factor. That can be the case with high availability application architecture. You rely on the native application technology to provide highly available applications (i.e. clustered SQL/Active Directory replication/load balanced web servers). However, certain types of applications may need lower latency between application components to remain under vendor support requirements. After ensuring highly available architecture at the application layer, you can use geo-diverse data centers for protecting against geographic or site failure.  

Real-world Proof

One of US Signal’s customers, Baystate Health, serves as a good example of a situation in which geodiversity makes a difference. With its entire data center operations located near its Springfield, Massachusetts location, Baystate Health lacked geodiversity in its DR plan. The organization’s IT team recognized that if a catastrophic event were to occur, the organization would not be able to recover essential applications and data — which could have a significant impact on patient care delivery.

Geodiversity in a solution wasn’t the only factor for Baystate Health to consider. The company needed a solution that fit within its tight budget parameters, be HIPAA compliant, and meet the health system’s requirements to have operations back up and running in less than two hours. US Signal was able to meet Baystate Health’s requirements with a solution that combined its Disaster Recovery as a Service (DRaaS) and an added DR site in Michigan. US Signal’s DRaaS, a fully managed, HIPAA-compliant solution, provides near-continuous, block-level replication for proven RPOs of seconds and RTOs of minutes. The additional DR site in Michigan, which is HIPAA certified as are all US Signal’s data centers, offers the needed geodiversity.

When to Go Geodiverse

US Signal generally recommends that geodiversity in data centers be considered in these three cases:

  • Disaster recovery
  • If the application supports it, running high availability across diverse data centers. There are many networking and access considerations to ensure sound architecture.
  • Power grid redundancy 

If you’re interested in learning more about what to look for in a colocation facility and colocation provider, download US Signal’s free eBook.

10 KEY CONSIDERATIONS FOR SELECTING A COLOCATION PROVIDER