IT At the LHC — Managing a Petabyte of Data Per Second

schliz writes "iTnews in Australia has published an interview with CERN's deputy head of IT, David Foster, who explains what last month's discovery of a 'particle consistent with the Higgs Boson' means for the organization's IT department, why it needs a second 'Tier Zero' data center, and how it is using grid computing and the cloud. Quoting: 'If you were to digitize all the information from a collision in a detector, it’s about a petabyte a second or a million gigabytes per second. There is a lot of filtering of the data that occurs within the 25 nanoseconds between each bunch crossing (of protons). Each experiment operates their own trigger farm – each consisting of several thousand machines – that conduct real-time electronics within the LHC. These trigger farms decide, for example, was this set of collisions interesting? Do I keep this data or not? The non-interesting event data is discarded, the interesting events go through a second filter or trigger farm of a few thousand more computers, also on-site at the experiment. [These computers] have a bit more time to do some initial reconstruction – looking at the data to decide if it’s interesting. Out of all of this comes a data stream of some few hundred megabytes to 1Gb per second that actually gets recorded in the CERN data center, the facility we call "Tier Zero."'"

Power limitations

[onyxruby]

Did a bunch of work with some stock exchanges a few years back. It was an interesting environment and I see that CERN had the same problems that the stock exchanges had. They even had the where the number one budgetary item wasn't cost but electric load.

You only had so much power physically available in the data centers next to the exchanges and server rooms inside them. Monetary cost was never an issue, but electric load was everything. It seems funny considering their load is strictly a science based load and not monetary, but their requirements and distribution remind me greatly of the exchanges.