Speaker
Description
The Deep Underground Neutrino Experiment (DUNE) utilizes CVMFS and CVMFS StashCache to distribute both its software stack and reference files for distributed computing workflows. DUNE utilizes CVMFS as it provides a read-only POSIX interface to StashCache, with the redundant features, e.g. built-in GeoIP locating, rate monitoring, and fallback in failures. During Dec-’21 to Jan-’22, it was found that DUNE HTC grid jobs were suffering from low CPU efficiency in the UK, due to slow access of data from a StashCache instance at Cardiff, which was intended only for LIGO jobs. A new UK StashCache instance at Edinburgh was implemented to solve this problem for DUNE as well as the other OSG experiments except LIGO in the UK. This talk will be from the perspective of the DUNE use case, to introduce the motivation, diagnosis of the inefficiency, deployment process, and current status/performance of this StashCache instance at Edinburgh.
