Data Gravity in a Converged Infrastructure


VMware’s Dave McCrory created the concept of data gravity. It’s a way to show how data has a gravitational pull.

Yesterday, I discovered a blog post by Steve Chambers, who works in the office of the CTO for VCE, the VMware, Cisco, EMC alliance. He uses McCrory’s theory to demonstrate how the conceept of data gravity applies to converged infrastructure. He calls it “VBlock Gravity.” VBlock is the converged infrastructure, big box technology from VCE.

Let’s compare that to McCrory’s definition from a blog post last Spring:

Consider Data as if it were a Planet or other object with sufficient mass.  As Data accumulates (builds mass) there is a greater likelihood that additional Services and Applications will be attracted to this data. This is the same effect Gravity has on objects around a planet.  As the mass or density increases, so does the strength of gravitational pull.  As things get closer to the mass, they accelerate toward the mass at an increasingly faster velocity.  Relating this analogy to Data is what is pictured below.

Chambers uses the term to demonstrate the benefit of convergence and how it is better, faster and cheaper than other methods. The more you converge, he says, the more you benefit.

But that also increases the data gravity, McCrory said in an interview today. In a converged environment, latency is minimal. But this tight integration also makes it difficult to move it off the converged environment.  The apps are tied in. Move it off and latency will increase.

I think he pinpoints the essence of the issue in a post he wrote about defying data gravity.

The speed of light is the answer.  You can only shuffle data around so quickly, even using the fastest networks, you are still bound by distance, bandwidth, and latency.  All of these are bound by time, which brings us back to the speed of light.  You can only transfer so much data across the distance of your network, so quickly (in a perfect world, the speed of light becomes the limitation).

The many methods explained here are simply a pathway to portability, but without standard services, platforms, and the like even with the patterns etc. it becomes impossible to move an Application, Service, or Workload outside of the boundaries of its present location.

Is that lock in? Yes and no. Portability is an issue that dogs infrastructure providers, be they integrated, converged infrastructures or public cloud services. Getting data from one place to another gets more complicated as the network grows.

A large market exists for VBlock. It’s what customers want. They like the fact that it is all built in. That’s the point Chambers makes. But, yes, if you want to move the data then it is going to be a task.

It’s just a matter of physics and the laws of data gravity.