What Goes On Tour...A visit to the NTT Data Center

Last week we found ourselves at the new Hemel Hempstead base for Nippon Telegraph & Telecom, or NTT Europe as they are better known. We were there for a tour of the new data center and our first task was to actually enter the building. Navigating the M25 had been a doddle compared to making our way through the stringent security. We provided ID, and in turn were provided with some pre-authorisation passes. We’d made it to the lobby! 

We were then warmly welcomed by the NTT team, and we proceeded to take in the meeting rooms and canteen areas - all spick and span as you would expect. However, normality was shortly suspended when we made our way back through to the lobby to a security door.  

Let’s face it, retinal scanning technology is always going to be cool, awesome and a little Mission Impossible, and NTT have it. It also meant that our access was restricted, unless accompanied by a member of NTT staff or a helpful security guard. Needless to say, as we stepped through the glass gate, we were impressed!  

Our cinema-esque analogies don’t end there though, as we then found ourselves in a matrix-like, ultra-clean and white corridor, with equally white doors that could quite easily have lead to the architects office. We were lead past these, to a grey one. This signified the gas room, where the early warning fire system comprising of compressed IG55 gas canisters was housed. It’s premonitive smoke-detection skills have never been used in anger, but it is constantly monitored and tested to help keep the data center as cool and fire-free as we found it.  

From there, we were taken to a room that contained part of the uninterruptible power supply (UPS system) for the data center. At least four hundred batteries stood guard, ready to power the building until the generators kicked in during a power cut. This room, one of two in a segment of six in the whole complex, would help keep the system running for 90 seconds if needed. We later learnt that the grey colouring of the door was to help identify where power is coming from, alongside an orange counterpart elsewhere in the building.  

Our tour then took us to the most ironically named room in the building. The cooling room was the hottest place we visited, and we don’t mean that in terms of appeal! Here the collective radiator systems from the computer cabinets and data centers pool their warm air, which can be used to heat the center in times of cold weather.  

Jurassic Park-like, we then followed the water pipes outside of the building and into a secure area, to some water cooling towers. Full-time residents of the U.K will not be surprised to learn that our little country is the perfect location for data centers, as the temperature means that the water can usually be cooled passively, without air conditioning. If it does get too hot, water sprinklers can be employed to dowse the radiators, which increases the cooling effect through evaporation, similar to some turbo powered race cars. If the mercury still goes skyward, then there are air conditioners to do the job, but even our recent June scorchers failed to cause concern.

This harnessing of heat and passive systems helps make the data center a much greener and eco-friendly operation, helping NTT and the data center achieve a Power Usage Effectiveness (PUE) rating of 1.2, considered excellent. The whole system is run autonomously via a central control system monitoring thousands of sensors throughout the building.  

On guard next to the water coolers were the four huge generators, on standby in case the two aforementioned power feeds ever went down for whatever reason. The guys at NTT mentioned they had enough diesel to power these for 72 hours, and they have four fuel providers ready to provide backup within 24 hours notice if needed. Needless to say, we didn’t get to see any of these things in action, which was a good thing.  

We then went back inside, to another white door and another retinal scanner. Once in, we were confronted by loud noise and cabinets filled with between 20 and 30 blade-type servers with carefully routed network and power cables. Each cabinet was sealed to allow collection of the hot air into the aforementioned coolers. Each server room also consisted of a rack of spares that were individually barcoded, enabling them to be entered into the bespoke system for easy reference. Should there then be a problem with the hardware, a system technician can instantly find the correct parts with a minimal amount of downtime.  

Our tour was nearly over as we walked back out into the corridor, but we did catch a glimpse of the servers for Spotify with their own room of blinking towers.  

NTT have provided our servers for over a decade, and our tour gave us a really interesting insight into how they operate, and into the setup of a modern data center. Our current server is now approaching the end of its life, and we approached NTT about an upgrade. The result was a tour of the new facility, and it’s good to know that our new server will be located in the very same data center we looked round and could literally touch - if we make it through security! Their operation gives us the confidence that we will be providing customers new and old with the same levels of excellent, uninterrupted service.