OTF#9 took place on March 24-25 at CERN [Indico] on the topics of the evolution of XRootD on Tuesday and WLCG accounting, information systems, and DC27 on Wednesday. There are comprehensive Live Notes attached to the Indico page.
XRootD: One of the main takeaways from the XRootD session was the need for a more regular stakeholder engagement process, though the experiments and ROOT developers expressed positive opinions of XRootD performance. The XRootD work plan was grouped into a short list of milestones (work in progress) including deploying the new monitoring before DC27, other performance challenges, etc.
WLCG Accounting: The second day focused on accounting evolution, where we heard from WLCG Operations on the evolution of the accounting system, which has been made all the more urgent by the end of life of the EGI accounting system at the end of June. The replacement consists of two components, AUDITOR and PEAR, which are the site probes and central accounting components, respectively. OSG uses GRAAC so the U.S. sites are not directly affected, though there is some development work needed on the OSG side to interface with the new system.
CRIC: Next we heard about the evolution plans of CRIC, the Computing Resource Information Catalogue. There is an ongoing migration to python3 that will continue during LS3. Much new information can be stored in CRIC, such as GPU resource information which will be able to be picked up by pilot submission systems. Power usage efficiency is now being recorded in CRIC (sustainability topic). There is also a proof of concept to put the FTS configuration in CRIC, but this will be done for FTS4 pending discussions with the developers. Finally, the careful use of AI agents is being explored.
DC27: Lastly, we heard from DOMA on the scope and scheduling of the next WLCG Data Challenge, DC27. The proposed dates are February 23 - March 6, 2027. A final decision (depending on FTS4 being released) could be made at the November HSF-WLCG Workshop [Indico], which could also serve as the pre-challenge workshop meeting. The first thing to focus on now is the target transfer rate, noting that production traffic in recent months has reached the peak levels of DC24 already.
The TCB continues to prepare for OTF#10, which will be co-hosted with HEPiX at their Spring Workshop in Lisbon [Indico] focusing on the mid- to long-term evolution of sites. Agenda topics include operational effort at sites, tape evolution and performance (report from OTF#8 [Indico]), and storage capacity vs. throughput. There will also be a session with presentations of site evolution plans from U.S. CMS and IHEP (China), which combined with information from other sites shown in OTF#4 last year [Indico] can be used to form the basis of Chapter 2 of the WLCG Technical Roadmap on Facility Evolution. There will also be a panel discussion on deploying services with k8s.
Significant progress has been made on most chapters of the Roadmap in anticipation of a plenary talk at CHEP26 in late May. There will be a practice talk at OTF#11 in mid-May.