While the LHCb experiment will be using a local data-centre at the experiment site for its computing infrastructure in Run3, LHCb is also evaluating the possibility to move its High Level Trigger server farm into an IT data-centre located few kilometres away from the LHCb detector. If proven feasible and if it could be replicated by other LHC experiments, the solution would allow the construction of a common HLT facility for sharing IT hardware resources with substantial cost savings.
The main challenges of the experiments are: the transmission of a very large amount of data over a scarce number of fibre connections; the relatively long distance to be covered; the use of shared, general purpose computer servers.
This paper describes the set up of the experiment, the different technologies considered and used, the challenges encountered and how they have been tackled.
The paper also tries to give guidelines and recommendations for the implementation of a solution that could be shared by all the LHC experiments.