A study case of Content Delivery Network solutions for the CMS experiment

In 2029 the LHC will start the High-Luminosity LHC (HL-LHC) program, with a boost in the integrated luminosity resulting in an unprecedented amount of experimental and simulated data samples to be transferred, processed and stored in disk and tape systems across the Worldwide LHC Computing Grid (WLCG). Content delivery network (CDN) solutions are being explored with the purposes of improving the performance of the compute tasks reading input data via the Wide Area Network (WAN), and also to provide a mechanism for cost-effective deployment of lightweight storages supporting traditional or opportunistic compute resources. In this contribution we study the benefits of applying cache solutions for the CMS experiment, in particular the configuration and deployment of xCache serving data to two Spanish WLCG sites supporting CMS the Tier-1 site at PIC and the Tier-2 site at CIEMAT. The deployment and configuration of the system and the developed monitoring tools will be shown, as well as data popularity studies in relation to the optimization of the cache configuration, the effects on CPU efficiency improvements for analysis tasks, and the cost benefits and impact of including this solution in the region.