LVC collaboration How do Virgo and Ligo share/compete for resources - Who can take decissions on sw, data management, sites... - For example, should virgo use ligo's git? - Offline sw is shared amongst both collaborations? - How is the analysis sw developed? Who 'owns' the sw?

SW management Current sw management rules at: https://wiki.virgo-gw.eu/Software_Management/WebHome Which sw is managed? - Online? - Framework? - User analisis? Role of the existing Ligo-Virgo Software Configuration Control Board (SCCB) in this game: https://wiki.ligo.org/Computing/SCCB /virgoApps more than 900 packages! - Review product/module breakdown Is there a "Testing environment"?, useful/needed to decouple from the operational one. - Not only for data analysis pipelines, but also at ‘framework’ level; e.g. to test Rucio, DIRAC, data exchange, bookkeeping, workload… How are the main pipelines developed? Internal group effort or collab effort? - Which are developed by Virgo? - Which are coming external to Virgo? SW distribution - Conda (Review of the corresponding proposal https://tds.virgo-gw.eu/ql/?c=13967) - Cvmfs - Singularity Newer toolings available - Git - If/when/how - CMT not maintained - Can we take the conda migration as an opportunity to replace cmt with something else? CMake, bazel… Automated release, packaging and distribution possible? - Roadmap

Offline activities Two main topics: - Data management - Workload management Tools to fit Virgo needs (Rucio/DIRAC/others) LIGO goes to Rucio - thus Virgo should, at least, be able to handle it. Pros-cons of tools to have an overall picture and ideally take a decision and run with it. Running LIGO-Virgo analyses on Virgo computing resources: status & plans Data storage - Which data is stored where? Virgo raw only in cascina? h(t) everywhere? Rewiew of the current relationship with Computing Centers.

Online processing Clarifications on data flow diagrams and processing modules - Computing just on raw Virgo data, or also on raw LIGO data? - Just on h(t), both LIGO+Virgo?. - DetChar/Quality: just on raw Virgo? Also on LIGO? - Processing raw data generates h(t), and also veto? - General review of data flow diagram to identify possible problems or limitations Migration/upgrade processes ongoing: storage, Kafka, etc. - Deadlines, tracking system, etc - For the Open Public Alerts (OPA) machinery (gracedb, gwcelery, lvalert, …) we are fully relying on Ligo, are we happy about it? - Bulk data handling (envision the future Data Transfer and Access integrated solution based on a EGI/OSG Framework) - GraceDB is managed by Ligo, are we happy with that?

Wrap-up and actions to be taken