CHRIS JOHNSON – RESOURCE ALLOCATION MANAGER

I initially studied Mathematics and Physics at the University of Nottingham, graduating in 1997. This was followed by an MSc in Computing at the University of Manchester and then a PhD in Theoretical Physics at the University of Liverpool. The latter was based in lattice QCD (quantum chromodynamics), a discretisation of spacetime used to study particle physics, where I was investigating a method based on the Lanczos eigensolver algorithm to calculate approximations of the fermion determinant which arises from the very large matrices used to calculate path integrals in particle physics. Calculating this is key to removing the so-called “quenched” approximation where fermion loops (dynamical quarks) are ignored. The larger the lattice the better the accuracy of the simulation but at the same time the more expensive the calculation so optimising the use of available compute cycles is important.

This gave me an introduction to parallel programming and running simulations on large HPC systems, specifically the Cray T3E at EPCC, where I now work.

Since joining EPCC in 2001, I have worked on all of the National UK Supercomputing Services run by EPCC in a number of roles and I have co-ordinated several funding calls both within the UK and across Europe where I was the co-ordinator of the Tier-1 resource exchange programme, DECI, and the industry HPC programme SHAPE, and I have also managed parts of the visitor exchange programmes TRACS and HPC-Europa. Up until recently I also co-ordinated and lectured on the Numerical Algorithms for HPC module given to EPCC’s MSc students.

Within DiRAC I am the Technical Manager of the RAC (resource allocation committee) where my main role is to manage resource allocations. The majority of this happens as part of the annual RAC calls and initially involves assessing what resources are available for a call, then later overseeing the technical reviews for the proposals that come in, and finally the allocation of resources and setting up of projects. In addition there seedcorn and discretionary projects to set up that come in throughout the year on a more ad hoc basis.