Indico has been updated to v3.3. See our blog post for details on this release. (OTG0146394)


Brian Paul Bockelman (University of Wisconsin Madison (US)), Maria Arsuaga Rios (CERN), Petr Vokac (Czech Technical University in Prague (CZ))

Topic: WLCG DOMA BDT Meeting

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Meeting ID: 998 3605 7922
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    • 1
      Hot topics

      Starting with next (16 March 2022) WLCG DOMA BDT meeting we are going to use different Zoom room (integrated with CERN Indico).

      SRM/HTTP Update (Petr)

      • CMS has moved its FTS to enable WebDAV + SRM/HTTPS (n.b. - in time for the tape exercise!)
      • FTS team is considering to enable this by default as there are few experiments who need this disabled.
      • Any issues arising?
        • Issues with DAVIX writing a temporary file on FTS server.  Probably FTS streaming issues.  Suggest FNAL ensures streaming is disabled.


    • 2
      Packet marking
      Speakers: Marian Babik (CERN), Shawn Mc Kee (University of Michigan (US))
      • Packet marking is part of the "SciTags" activity in the Research Network Technical WG.  95 members from 50 orgs.
      • Primary goal: allow tracking and correlation of transfers with R&E network provider's network flow monitoring.
        • Can associated flows with a specific experiment or activity.
        • Provides sites with more visibility into network flows.
      • How tags works:
        • Packet marking: markers are added to each packet.
        • Flow marking: UDP firefly sent out periodically, associated with the flow.
        • Network-level collectors at the respective entities collect fireflies or examine packets; hook into the respective analytic platforms.
        • See:
      • WLCG:
        • Experiment-level systems have knowledge, pass it to FTS3.
      • Status:
        • Flow marking works with IPv6 and IPv4, hence is the focus.
        • XRootD 5.4.0 supports UDP fireflies.
          • N.b. - XRootD docs:
        • External-to-storage script based on netstat information.
        • ESNet and Jisc/Janet have deployed collectors.
        • Simplified deployment was done during the last data challenge.  Able to correlate UDP fireflies with netflow data.
      • Various additional links to the project on the slides.
      • Discussion:
        • Does the prototype work with HTTP?  A: Yes (Brian thinks it might not work with HTTP push)
        • Technical discussion - note that the fireflies are only sent at beginning and end?
        • Timeline?  DC2023.
        • Who is onboard?
          • ATLAS is enthusiastic, others are backing / provide interest.
        • What about dCache?
          • Currently used the netstat version.
          • dCache team is aware of the activity but not clear if there's a timeline yet.  ACTION ITEM: Need to get input from Tigran.
        • How are flows marked precisely?  E.g., HTTP headers?  TBD.


    • 3
      Token Authorization testbed
      Speaker: Francesco Giacomini (INFN CNAF)
      • See attached slides.
      • Current testbed gets nightly and also Jenkins integration
      • Walked through last night's results.
      • Open issues:
        • Assumes use of issuer implies group membership.  Decision: must be explicit
        • Group vs Scopes.  Decision: both.
      • XRootD failures:
        • There are some open items, mostly around the HTTP status codes.
        • ACTION ITEM: Organize a discussion with Francesco, Brian, Elvin (maybe, TBC), and someone from RAL.  James Walder.
    • 4
      Tape REST access
      Speaker: Cedric Caffy (CERN)
      • Last Friday, finished the discussions of the REST API.
      • Not switching to doing the REST API reference doc to capture the agreed approach "on paper".
      • CERN CTA prototype is working to implement the final draft.
    • 5
      • CMS reconfigured to TAPE transfers to SRM+HTTPS
      • CERN FTS3 public instance will be reconfigured to also prefer HTTPS for as SRM TURL protocol (RQF1986690)



      Tokens and testing (Maria):

      • Can we retire the HTTP-TPC nightly email?  Effectively already done due to technical issues but we can probably just retire this as HTTP-TPC is in production.
      • Should we commission a XRootD protocol testbed?  Probably too early - need more agreement on the approach.
        • Recap of discussion on XRootD ZTN GitHub issue: