Tuesday, 20 March 2007
Power is the currency
We host our SMS Service applications in one of the Global Switch hosting facilities in London. These facilities are super-secure, highly available and historically were priced based on the space you occupied. Times have changed, we are at contract renewal time and the currency is now the amp. The processing power of servers has got denser and denser, ie more work can be done in a smaller volume. The introduction of blade servers now provides units that are 7U deep and can hold 20 dual core processors, and 20 drives, giving awesome computing power but also awesome power consumption and heat output. This gives the data centre operators a real issue, when before 12 amps was enough for a rack and the temperature management system was more than adequate to cope, it is very easy to be pulling 20 amps per rack with a standard set of servers. This creates power density and heat dissipation problems that the original setup wasn;t designed for. There is a vervent amount of upgrading of environmental systems at these facilities but with that comes a very different price tag. But the flipside is cramming servers into racks is no longer an issue, the chance of finding one that will take the load is remote/v.expensive. So what does that mean for us? Our SMS server applications are based on a multi-component, distributed architecture enabling us to scale out by just adding more servers. We're currently refreshing our current set of application servers and the original plan was to go for blade arrays to keep the space utlitisation down. This change in rules as meant we can look at good old fashioned pizza box servers like the Dell PowerEdge 860. It's cheap (relatively), powerful (can have quad-core processors) and best of all doesn't draw much power. We can also space them out in the racks quite nicely to keep them running cool and optimal.