CT Examiner spoke with Dr. Lin Zhong, a professor of computer science at Yale University, about his research on cloud and edge data centers to help our readers understand the opportunities for information technology in Connecticut, and the recent controversy regarding plans by NE Edge to build data centers in Groton.
Zhong has said his research is concerned with both mobile computing and how information technologies can serve people untethered.
What is the difference between an “edge” data center and a cloud data center?
Edge data centers are located closer to the user populations and tend to be much smaller than a cloud data center.
The big companies — Apple, Microsoft, Google, Amazon — have their huge data centers in rural places like the eastern Washington state. When you request something — say a page from Amazon – it would go from your phone to the base station of the mobile network, through the internet backbone and then get routed all the way to the cloud data center that provides shopping services. The page will be sent back to your phone on the same route in reverse. This round trip could be hundreds of milliseconds because of how far away the cloud data center is.
What is latency?
It’s the time it takes for an electronic signal or “packet” to travel the distance from a device to a cloud service and back again.
The fastest a packet can travel is the speed of light, so the distance becomes the physical limitation.
To reduce latency, we have to move the data center closer to the people so that the electronic signal travels a shorter distance.
Why does shorter latency matter?
New and upcoming technologies will need shorter latency – for example, self-driving cars, augmented reality and virtual reality (ARVR) applications, mobile gaming, telemedicine. Also, everyday uses, like streaming a movie from Netflix, will be more efficient with shorter latency.
Who owns and finances the edge data centers?
Usually they are owned by the cloud vendors, like Google, Microsoft and Amazon. They rent time on their servers in the edge data centers to smaller vendors.
But when they are putting in an edge center closer to the user population, they are building smaller data centers, sometimes they partner up with a group that will deal with the local politics and will set up the physical data center and then rent from that group.
Why put edge data centers in Connecticut?
Just by looking purely at the geographic distance, Connecticut is close to two very dense metropolitan centers – Boston and New York. Connecticut is in a strategic location to provide these population centers with short latency.
What are the factors needed for a successful data center?
From an engineering perspective, I think the number one thing is a reliable power supply, and a high speed backbone network because you want it to be ready to run. You have to have the fiber and the reliable power supply because you don’t want to have a power outage from time to time. The cost of electricity will be a factor as well.
What are the potential detriments of an edge data center?
It’s all about how you build it, taking measures to control the environmental impact. It requires being careful in finding the right location. Backup generators or batteries are needed for power outages.
If you do a good job, these things could be neutral. You could argue that the edge center is greener because the packets no longer travel to servers in the state of Washington and back, so you actually reduce the electricity of your services.
How should a community consider water usage — used for cooling — in the siting of data centers?
Regarding cooling, again, it depends on how you build the data center. The cheapest way to cool is to evaporate water, which, not surprisingly, uses a lot of water. In recent years, there is a lot of push in the data center industry to be more efficient in water use, e.g., recycle cooling water or use wastewater. But these technologies are more expensive. So yes, the communities should ask the data center builders about their projected water usage.
How long will cloud technology be around? Will there be abandoned data centers in 20 years?
Not anytime soon. The cloud system will become more hierarchical and each layer will become optimized for different things – and you end up with a more efficient system.
A lot of the economic development is going to be determined by your cyber infrastructure, how fast your networks are, how short the latencies are. Cyber infrastructure is an important part of the nation’s infrastructure for us to be a competitive economy and to be a leader in innovation.