LHCONE R&D and RNT-WG call

Tuesday 1 Jul 2025, 17:00 → 18:00 Europe/Zurich

Edoardo Martelli (CERN), Joe Mambretti (International Center for Advanced Internet Research Northwestern University), Marian Babik (CERN), Shawn Mc Kee (University of Michigan (US))

17:00 → 17:20 LHCONE

Presents: Edoardo, Martelli, Maran Babik, Asif Shah, Jim Chen, Ryan Heath, Tom Lehman, Bill Johnston, Daniela Brauner, Pablo Soto, Phil Demar, Petr Vokac, Karl Newell, Dale Carder, Joe Mambretti, Harvey Newman

LHCONE
- next meeting
- Large community for LHCONE: Edoardo will work with Dale.

SC25
- Joe: Demo of Scitags at 1.2Tbps. DTNs will be in UVic, Starlight and the SC venue.

Next meeting:
- 26th of August 

17:20 → 17:50 RNTWG

Speaker: Pablo Collado Soto (Universidad Autonoma de Madrid (ES))

eBPF TCP Info.pdf

Registry & Domain 
- Following up

Collectors
- Meeting about collectors took place with Jisc and GEANT
- ESnet planning to establish public Kafka cluster that could be used to inter-change data between R&E collectors
    - We're going to test it with GEANT(eu.scitags.org) collector passing fireflies to ESnet
- Discussed operating model
- Looking for good use cases for network operations that would motivate Scitags deployment
    - One such could be improving visibility of LHC traffic on GPN (nonLHC) as well as better granularity within LHCONE
    - Correlation with network operations data might be another (sFlow, etc.)
    - Ideas, suggestions and/or experiences are welcome

- Contacted by Andrew Elwell, currently working at Pawsey HPC in Australia
  - They’re interested in Scitags to get better visibility into network flows, they’re running mainly astro-physics (SKA/AusSRC, ASKAP, MWA)
  - We're looking for contacts in SKAO and AARNET (potentially to operate Asia/Pacific collector)

Collector Dashboards 
- Topology: One of the re-occurring topics is ability to assign IP addresses to sites
    - WLCG CRIC is good source but has only LHCONE/LHCOPN prefixes
    - Looking for ways how we could collect all prefixes from all sites using Scitags 
- Two new dashboards
   - R&E dashboard - some minor changes and fixes, throughput calculation and topology needs some additional work 
   - Site dashboard - looks at performance of the storage system (pool nodes) 

Experiments
- LHCb plans to review our requirements and implement Scitags in the next couple of weeks

dCache 
- 10.2.13 testing at AGLT2. We found a possible memory leak that we need to track down and fix before testing can continue

FTS/XRootd (investigated missing fireflies at CERN collector)
- Backtested Xrootd implementation to compare 5.7.0 vs 5.8.0 and how it behaves wrt. HTTP headers
      - Details at: https://docs.google.com/drawings/d/12vKqCK33LkgQxKwcayxxGRXcOcD6GOKrumx72jzb0m8/edit?usp=sharing
- We need to decide whether we want to be able to collect all traffic related to a specific site (at that site) 
      - This is important if we want to run site collectors, but also for overall coverage (to avoid requiring all sites to support scitags to get all data)
      - To achieve this, we will need to request FTS to modify the HTTP headers in GET requests so that the source site issues the firefly instead of the destination.

flowd-go
- Meeting with Pablo at CERN, some updates on eBPF and netlink readout
- flowd-go containers are now public

17:50 → 17:55 AOB

17:55 → 18:00 Next meeting