Present: Roland H, Bill G, Ken S, Peter D, Karim S, Steve B, Atul K, Indrani B, Erik S, Zach E, Maria H, Miguel G

Chair: Roland H, Minutes: Bill G

* SPEC benchmark contribution [https://bitbucket.org/einsteintoolkit/tickets/issues/2470 task] [RH, SB]

Steve, no new news.

* ET 2021 summer workshop [https://docs.google.com/spreadsheets/d/1zNnN5kTh_X0_Le_UDCFbTlavOcjwLNh6pxRI... date selection]

Roland, another virtual only ETK meeting this summer hosted by NCSA.  Trying to avoid other large meetings.  Fill out the spreadsheet in the mailing list and linked on the above for conflicts.  A full week, 5 days and 1/2 day for the school in the morning likely. Schedule: Votes 8 of 13 are yes for August 16-20.  And July 12 to 16, 4 yes's and 2 no.  July 26-30, 7 yes and 1 no.  August 16-20 and July 26-30 seem more preferred.  Check with LIGO meetings and make an announcement within the week.

Roland, collecting ideas for lecture topics.  You as a user or other people that would like to hear about ETK and basics like Num Rel by Helvi, and hydrohynamics and magneto-hydrodynamics.  Steve will give intro tutorial.  Yosef on writing a more advanced ETK thorn. Still in brainstorming phase so please send emails.  Erik, would like Wave Extraction and a bit of theory behind it, generic how to analyze the data that come out of the ETK, and how to read them into Python or Mathematica and what you can do with it.  Roland, Also thinking about KuiBit, or Ian Hinder's tools, and Wolfgang's PostCactus.  How to use and to program in them.

Roland, Presentations, getting input from numerical astrophysics groups, AMRex, Charm++, etc.  Athena version with full GR in it. Erik, consider GR 1D by Connor, black hole formation with hydro but cannot handle black hole itself.  Roland, idea is to have the competition give a presentations.

Atul, last years meeting there was desire for Lorene tutorial / introduction. Maria agrees.  Lorene with ETK and not the independent one. Roland, read data or construct data?  RIT on constructing and reading is the thorn.  Maria, would like how to integrate with tabulated EOS, and using it.  Construction of initial data with various EOS in the ETK, in all the various forms for the EOS.  Roland will contact Josh Faber (RIT) to ask about the construction of EOS, and to ask if they would show us how to use the generated data in the toolkit.

Will also have Lightning talks, 7 + 2 minutes.

* release planning [ZE]

** release [http://einsteintoolkit.org/testsuite_results/index.php testsuite status]

[https://docs.einsteintoolkit.org/et-docs/Release_Details Release Details]

Zach, one month before Gallery examples need to be tested--- Feature Freeze May 15th.  Steve, not tested BBH example recently, but running testsuites, QBC, Deep Bayou, and generic linuxes... about 15 hydro tests do not pass QBC and DB---assertion error in con2prim, maybe not unusual, see on other systems (discussed last week too).  These are all Intel compiler and not GCC. Discussion of QB which mostly passes, QBC with failures, and Deep Bayou with failures between Steve and Roland.  Looks like the Intel 19 compiler might be in common with the failures.

Gallery examples after the feature freeze definitely.  Testers should test the example earlier if you have not run it recently. There are tickets for each of the examples.  "Testing each example" tickets will be put in the details; see link above and "Gallery Example volunteers" section.

* [http://blackholesathome.net/ BlackHoles@Home] & the Toolkit [ZE]

Zach, giving the APS talk on Sunday and in preparation the BlackHoles@Home website is updated, and code validation has been added.  Runs binary BH on a desktop computer, and presents the gallery example from the ETK.  Details there on what he did. Perfect agreement for l=2, but less so for l=4 because of high frequency gauge mode bouncing off of refinement levels. BH@Home does not use the symmetry about the z=0 plane. Can have resolution in different directions independently.  Would like to link to the ETK in library form, interpolation to small cartesian grid patch over to the toolkit as a library to get isolated and apparent horizons from ETK.  Has a proof of principle with Roland in Bitbucket using ETK as a library.  So ETK will be in BH@Home to do this code verification and comparison.

Steve, BH@Home the users running them do not know what sims they are running?  Zach, trying to be very transparent with the users, no visualization yet.  Goal is 1M of time in an hour on a desktop.  Have two servers with good 10GB fiber lines for receiving the data and large storage 70 TB---with 20k users in mind.  Postdoc on client-server interface working.  Linux and Mac versions are good, but Windows is a bit more difficult. Looking to launch in August of 2021.  Checkpointing and resuming from checkpointing for now.  Setting up jobs from the server and passing them out to clients and resuming when a desktop disappears off the net.

[https://www.einsteintoolkit.org/tools/unanswered.php unanswered question on mailing list]

None

[https://bitbucket.org/einsteintoolkit/tickets/issues?status=open&status=... open tickets sorted by update time]

Compiling on MacOS resolved or partially so in private emails.

[https://bitbucket.org/einsteintoolkit/tickets/issues?status=new&status=o... tickets ready for review]

* AOB

Erik, do we follow up on those who try ETK?  Do we know why they leave?  Can we help more?  Maybe a questionnaire after a few days---the "onboarding process."  Maybe two questionnaires, one when they register and another a few days after the start using it. Is there an Outreach section in someone's grant for resources?

Roland, we currently do not follow-up.  Record of emails and hash of emails in the login...which we could figure out.

Steve, have been getting many membership and tutorial requests in the last days.  Anyone teaching or running tutorials using ETK? No one knows of any.