An http data-federation ecosystem with caching functionality using DPM and Dynafed

Abstract

The implementation of cache systems in the computing model of HEP experiments enables to accelerate access to hot data sets by scientists, opening new scenarios of data distribution and enable to exploit the paradigm of storage-less sites. In this work, we present a study for the creation of an http data-federation ecosystem with caching functionality. We created plug-in integrated in the logic of a DPM Storage, able to reproduce a cache behaviour, taking advantage from the new feature introduced in the last version of Disk Pool Manager, called volatile-pool. Then we used Dynafed as lightweight federation system to aggregate a set of standard Grid Storage together with the caching system. With the designed setup, clients asking for a file present on the Data-Grid are automatically redirected to the cache, if the cache is the closest storage, thanks to the action of the geo-plugin run by Dynafed. As proof of the concept, we tested the whole system in a controlled environment within the Belle II computing infrastructure using a set of files located in production Storage Elements. Preliminary results demonstrate the proper functionality of the logic and encourage continuing the work.