In IT, ‘Cloud Computing’ is a term that can be applied to companies offering very different services. Everything from Airbnb, Microsoft Office 365, Uber, Xero, and even internet banking are considering cloud services.
- So, what does “the cloud” actually mean?
- Why has cloud only become popular so recently?
- How do you buy cloud?
First, the basics:
- Cloud-based IT services use technology you probably already know and understand
- At its core, cloud is a large group of servers
- Fast Internet & virtualisation were the two industries that made cloud computing IT possible
- Today, everybody can buy server capacity by the kilo
1. “The Cloud”: it’s technology you already know
At the basic level, ‘Cloud’ computing is a bunch of servers in a data centre. That Data Centre may have hundreds of servers or, in the case of Amazon, Google or Microsoft, tens of thousands of servers. Thousands of data centres drive the cloud all over the world
Whenever you run anything on the cloud you are connecting to one of these servers in one of these data centres, which you’ve been using for the last 20 years.
2. Fast internet & virtualisation made “the Cloud” popular
Two elements have meant that Cloud-based IT services are more popular and servers better in the cloud. These elements are:
Faster Internet
A server computer, by definition, is constantly sending and receiving information to and from its client computers (e.g. Windows workstations, notebooks, iPads etc.). The faster the link between server and client, the better the arrangement works.
From a very early point (the mid 80’s in fact) the twisted-pair cabling that handled the communication between server’s computers and client computers at your office has run at exceptional speeds. Twisted-pair cabling doesn’t work at distances greater than 200m. So while it is great for inside the office, it’s poor for carrying the data from your building to another building or data centre.
For decades telephone cables were used to carry data to data centres at a much, much slower rate. That slower rate made telephone cables infeasible to have servers outside the building for all but a few applications, like Email and web browsing, that could still function at the slower speed.
It is only in the last 5-10 years, with the proliferation of Fibre Cable, that we can get the same sort of speeds to the server in a data centre no matter the location.
Server Virtualisation
Before virtualisation you would buy a physical server and install an operating system on it – either Windows or Linux. That box would then become either a Windows Server or a Linux Server.
If the physical box came with 16Gb RAM, then the Windows Server had 16BG RAM.
If the physical server came with two 4 x CPUs then the Windows Server had 4 x CPUs.
These days we install virtualisation software before we install Windows or Linux. The very clever Virtualisation software acts like a broker for resources in the physical box. When we install Windows server software on top of the virtualisaton software we get to control how many of the CPUs are seen and used. The same goes for how much memory the Windows server gets to see and use. We can then install Linux on the same box later. Both operating systems are unaware of the other and think they have the hardware to themselves.
In IT cloud computing, virtualisation is the key to hiding complex underlying software or hardware under an intelligent abstraction layer.
3. What happens when you can buy “servers by the kilo”
A cloud-based IT service provider will buy thousands of physical servers and put them in a data centre. Each of those physical computers can be sliced and diced into smaller ‘virtual’ servers giving you the chance to buy ‘Servers by the Kilo’. You can ask an IT cloud provider for an 8GB, 2 CPU server today and it will be provision that on one of the servers. Ask for a bigger one later, and that can be provisioned elsewhere.
There are tremendous advantages of scale to be had when we run thousands of servers from the same building.
Microsoft Azure is the best example of this. They have tens of thousands of physical servers in data centres across the world and each of them contains virtualisation software.
So cloud is cheaper, OPEX driven and a flexible fit, with faster internet and enabling technology to support it.