Amazon Web Services is an unrivalled colossus of the internet age, providing the computational
horsepower underpinning countless organisations from Netflix to BMW, Disney to GE, Tinder
to the CIA.
It earns tens of billions of dollars a year, and if you’ve used the internet at all lately,
you’ve probably used Amazon Web Services without even knowing it.
But where is it?
What is it?
And how does it all work?
Join us now as we enter the belly of the beast and take a sneak peek inside an AWS data centre.
In stark contrast to its cardboard boxes, vans, trucks, jet planes and warehouses, Amazon
prefers not to brand its vast portfolio of gargantuan data centres.
But these monumental server farms are the very guts of the firm’s wildly successful
AWS – that’s Amazon Web Services – division.
AWS began life at a 2003 meeting in the lakehouse of CEO Jeff Bezos.
The firm had just emerged strong from the Dotcom bust, but Bezos’ fast-growing retailer
was having difficulty setting up and rolling out its own internal server capacity.
A scheme promising fast, scalable server infrastructure was duly hashed out.
And was swiftly identified, by the more enterprising young guns in the room at least, as a potential
spinoff service Amazon could sell on to other companies.
Fast forward to today and AWS rakes in a whopping 60% of all Amazon profits.
That’s about $50 billion a year.
How?
By taking on other companies’ tech problems, in the ‘cloud’.
If you’re a startup in 2021, you no longer need to invest precious capital in vast banks
of noisy, expensive servers and battalions of nerds to maintain them.
You just rent time on Amazon’s gear instead.
That’s the cloud.
When you’re busy, yay, you hire more gear.
If you’re quiet, whatever, you hire less gear.
The actual gear in question is jealousy hidden from prying eyes by Amazon.
Even clients aren’t allowed to poke around in the data centres they pay for, and their
addresses aren’t made public.
But here’s what we know.
Take a typical site, in Loudoun County, Northern Virginia.
AWS is said to run at least 50 individual data centres in this region alone, covering
several million square feet.
Believe it or not, Amazon is planning on adding still more capacity in Northern Virginia,
for instance a 100 acre site near Dulles airport the firm reportedly just shelled out a cool
$73 million for.
On entry to one such data centre, let’s say this giant nondescript box next door to
a pet resort in Sterling, the first thing we notice is that security is the over-riding
concern for AWS.
There’s high fences, guards, and several layers of intrusion detection systems, most
obviously cameras.
When access is permitted, to very limited people for very limited periods, two-factor
authorisation is required on at least two occasions during the visit.
If a visit is sanctioned – this is extremely rare – visitors are accompanied at all times
by at least one authorised member of AWS staff.
Once this so-called ‘perimeter layer’ is passed, the next stage of the data centre
is known as the ‘infrastructure layer’.
This is where crucial systems like backup power, fire suppression and most importantly
HVAC, or air conditioning, is situated.
To maintain market dominance, AWS data centres cannot be allowed to fail, ever, for any reason.
As such water, power, telecommunications and internet links are all designed with full
redundancy.
And keeping all those servers – as many as 80,000 in a single data centre – running
requires constant monitoring of ambient temperature and humidity to prevent overheating.
If the worst should happen and a fire breaks out, a suite of systems involving water and
gaseous sprinkler systems are rigorously maintained and good to go in a crisis.
Past the infrastructure layer and we’re finally where the real magic happens – the
so-called data layer.
Security is even tighter here, with a secretive array of intrusion detection systems and even
stricter review process for anybody going in or out.
Even if something minor happens, for instance an internal door is held open slightly longer
than usual, alarms are triggered.
All access points are fortified with multi-factor electronic control devices.
If a data breach, physical or virtual, is even so much as suspected, the relevant server
is automatically disabled and shut down.
These security systems are audited throughout the year according to a robust 2,600-point
checklist supervised by external bodies.
These external auditors can request access to anything in the data centre, from humdrum
logs to security footage or even the very cameras themselves.
AWS staff are sometimes plucked at random from their shifts and interviewed about topics
like the disposal of media, itself a process that’s held to exacting and robust compliance
metrics.
Let’s look at the hardware itself.
In the midst of all this hyper security, it’s maybe easy to forget that AWS data centres
are fundamentally just enormous banks of servers.
A typical AWS data center will hold anywhere from 50,000 to 80,000 servers, running on
a combined 25-30 megawatts of power.
It’s said that AWS could quite easily double this size and make even bigger data centres.
However, like everything Amazon related, it’s all a question of finely-calibrated scale.
Distinguished engineer and AWS VP James Hamilton told attendees at the company’s re:Invent
conference in 2016 that beyond a certain point, increasing the number of servers and racks
per centre no longer lowers the incremental cost.
‘At some point, the value goes down and the costs go up, and in our view, this is
around the right number,’ Hamilton says of the datacenter size AWS usually goes with.
Thrillingly, Hamilton employs the term ‘blast radius’ to underscore the impact a failure
might lead to in a much larger data centre, hence the relatively modest dimensions.
Still, 80,000 servers is plenty, designed to take in – according to Hamilton – some
102 terrabytes of data each and every second.
Significantly, the engineer also hinted that bandwidth within the centre is ‘wildly higher’
even than that.
Ever evangelists for vertical integration, Amazon have made great strides in streamlining
and perfecting the servers themselves over the years.
Unlike other colocation server infrastructure providers, AWS has a much clearer understanding
of who will be using its hardware, and for what.
Removing this requirement to be versatile and generalist has enabled the firm to devise
ever more efficient server architectures.
When mundane software operations are translated on the hardware, or even the very silicon
of the chips, this can shave nanoseconds off of processing times.
And at Amazon scale, that makes a big difference.
Initially AWS bought servers ‘off the peg’ as it were from traditional suppliers.
But steadily over time the firm began developing its own single-depth servers, exquisitely
optimised for airflow in AWS buildings running AWS software.
AWS has even developed its own so-called ‘Graviton’ chipsets since acquiring Israeli firm Annapurna.
These Graviton chips, currently in their second generation with a third on the way, use the
power-efficient ARM architecture.
This represents a break from long-term Amazon partner Intel and it’s x86 architecture,
and is said to give AWS clients 40% better price performance – essentially putting
supercomputer-level power in the hands of regular commercial users.
In terms of storage, a single standard-sized rack in an AWS data centre can hold 11 petabytes
– that’s a million gigabytes – of data on 1,100 disks.
Multiplied, of course, many thousands of times, across many hundreds of data centres.
All around the world.
AWS routers – here comes the science kids – run custom ASICs, or Application Specific
Integrated Circuits, that support 128 ports with 25 gigabit ethernet connectivity.
This diverges, fun fact fans, from the industry standard 10GbE and 40 GbE networking speeds
– but apparently, according to James Hamilton, offers economies of scale when paired together
at 50 GbE.
Networking between data centres – essential to provide security and backup for crucial
client info – happens over Amazon’s own private 100 gigabit Ethernet network, which
connects the 25 international regions and 80 so-called ‘Availability Zones’ across
the vast AWS worldwide network.
AWS even lays its own private undersea cables.
But back to our datacenter.
Cooling is an overriding priority, and to minimise environmental impact AWS, in particular
in Loudoun County, Virginia, set out to use as much reclaimed water as possible.
This stops the company hogging all the precious local drinking water, which would obviously
be a PR nightmare.
Loudoun Water, the local utility, are happy to provide this reclaimed water at a competitive
rate – AWS pay serious taxes here – but it’s worth noting that elsewhere AWS has
installed its own on-site water treatment systems.
These prevent pipes clogging up with mineral sediment, which in turn causes costly hassle
and delay.
And if you think that’s crazy, the company has even started developing its own power
substations.
All those servers use a fair bit of juice, so instead of waiting for slow-moving traditional
power companies to develop infrastructure to keep those all-important racks humming
at all costs, AWS, simply builds electric substations itself.
Day to day operations within the data centre are described by some ex-technicians as being
akin to an ER department for computers.
With that much hardware, inevitably things seize up, stop pinging or require a reboot.
Fault finding and upgrading equipment is left to a small army of techs who follow rigorously
drilled playbooks that cover almost any conceivable eventuality.
Metrics are set by supervisors encouraging teams to complete tasks quickly and efficiently.
Some have complained that the working environment is cold, and it’s certainly very loud.
In future we can expect to see many more, and even louder AWS data centres come online.
From early 2020, a new AWS centre opened in the Northern Virginia area alone every three
months, totalling around one million square feet in footprint.
And that’s just one area.
All in all, it’s quite the numbers game.
What do you think?
Do these vast data centres get the credit they deserve for underpinning so much of modern
life?
Let us know in the comments, and don’t forget to subscribe for more supersized tech content.