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'Going Spatial' is my personal blog, the views on this site are entirely my own and should in no way be attributed to anyone else or as the opinion of any organisation.

My tweets on GIS, Humanitarian, Tech, Games and Randomness

Wednesday 5 May 2010

ArcGIS and Amazon

First technical blog for me though I have been blogging under a number of different guises in different subjects for a while, mainly online gaming and photography but I needed a log to keep track of what I was doing, merely as a reminder to myself.

Amazon Web Services (http://aws.amazon.com/) has been a new offering to the market providing fast, reliable and economical cloud computing to anyone who wants to pay. As someone who is managing a hosting service, AWS provides very quick access to resources that would otherwise cost me and the business thousands of pounds just to get started in terms of new machines and licenses. Amazon Web Services gives almost instant access to pay-as-you-go infrastructure and this is a great thing.

Cloud computing has been around for a while but AWS has made it easy for individuals and companies to access it - with a relatively clear pricing structure so that one can keep a track on the cost on a daily basis. Once a service is not required, you can throw the AMI away and not have to worry about disposal/recycling of hardware. This evolution is a natural process for our hosting team: we started off with a few servers, that grew to a few more servers than shrank down to a handful of big servers running virtual machines to now using the cloud.

The evolution of hosting at ESRI (UK)

Year One to Four
One very big project made it a necessity to set up a dedicated team and infrastructure to host an innovative web service. Over the three to four years, the service and accompanying infrastructure grew and grew. Kit was replaced several times and a growing pile of older, possibly obsolete servers started to cause us issues in terms of reliability, storage and recycling/disposal. 

Year Four
The web application and web service was sold off to a third party - who naturally wanted new kit in their new hosting centre. We were left with the older kit to run other hosting applications. It became a balancing act to ensure that we had enough hardware to run existing applications well and to have enough flex room to take on more work. However, we had to be careful that we didn't grow too big in terms of kit without a hosting contract to pay for the kit.

This balancing act went on for a couple of years. A few big hosting contracts were won and this required even more new kit, the cycle was repeating itself and the balancing act was maintained.

Year Five to Six
Virtualisation was touted as a possible answer to lower the cost of ownership down. The idea is very attractive: get a big host server and replace dozens of physical servers with the same number of virtual machines. Spin them up as required and adjust their resource requirements on the fly. Total Cost of Ownership (TCO) should come down as one does not need to buy new kit and there is a saving in power requirements. However, licenses for servers and application still need to be purchased and the 'entry cost' was merely shifted from cost of buying the kit to licensing the software. Still the monetary savings on power alone through virtualisation was significant. The ease of backup and recovery was also noted - a dead virtual machine can be switched off and replaced by a backup virtual machine in a few minutes. No need to keep extra kit involved and the clutter in the server room was reduced. We still had the headache of patching the virtual machines each month made more complicated by the need to spin up back-up VMs to patch and maintain.

Year Seven
Cloud computing offers up an expansion of the in-house virtualisation in that short-lived, high-intensity applications can easily be made available on the cloud and then switched off / thrown away when finished. The OS cost is included in the daily fee so savings are immediate. Creating new VMs in the cloud is easy and the ability to utilise very large servers (in terms of CPU and RAM) is as easy as making a new choice when you are spinning up a new instance. One has to learn a new vocabulary when in the Amazon cloud as well. The ability to keep AMI patched up is still an ongoing issue but the 'entry cost' to hosting has now been almost eliminated. There is no need to buy kit or to license operating systems (or even databases if you opt to use the PostgreSQL AMI) - so a bare-bones system, running IIS can be up and running in a matter of minutes.

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