Speaker
Description
Version 4 of the File Transfer Service (FTS4) is currently under active development within the CERN IT Storage group. This aims to address issues which have prevented version 3 from being proposed as a candidate for automating bulk file-transfers during LHC Physics Run 4.
FTS4 has taken an incremental rather than big-bang approach to its development. FTS4 started with the FTS3 code base and then replaced target areas in a piecemeal fashion, keeping a fully functional system available at all times. This availability has purposely allowed FTS4 to be field tested with the LHC experiments at a relatively early stage in its development cycle. This was a critical goal in planning. We must ensure FTS4 addresses experiment requirements and does not drift away from their core expectations.
The early field testing of FTS4 started with the ATLAS experiment towards the end of 2025 and finished with CMS and other interested parties by the end of the first quarter of 2026. This paper describes the goals of FTS4 and its developments, reports on the findings of the first field tests with the experiments and concludes with a description of the next steps.