October 2017 - mpiwg-ft - mailman3.cels.anl.gov

Re: [mpiwg-ft] Subjects for Tomorrow's FTWG Call
by Van Der Wijngaart, Rob F 31 Oct '17

31 Oct '17

I don't have any topics to discuss at present. Rob -----Original Message----- From: mpiwg-ft [mailto:[email protected]] On Behalf Of Bland, Wesley Sent: Tuesday, October 31, 2017 1:04 PM To: FTWG <mpiwg-ft(a)lists.mpi-forum.org> Subject: [mpiwg-ft] Subjects for Tomorrow's FTWG Call Hi all, I think we're still on hold for the ULFM data resilience discussion until we're able to get some more feedback from Jeff and our non-ULFM topics are ready for another discussion with the rest of the forum. Are there other topics that people want to discuss tomorrow or should we cancel the call? Thanks, Wesley _______________________________________________ mpiwg-ft mailing list mpiwg-ft(a)lists.mpi-forum.org https://lists.mpi-forum.org/mailman/listinfo/mpiwg-ft

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Re: [mpiwg-ft] Subjects for Tomorrow's FTWG Call
by Jeff Hammond 31 Oct '17

31 Oct '17

What feedback do you want? I haven’t seen any specific requests for comment. Jeff On Tue, Oct 31, 2017 at 1:04 PM Bland, Wesley <wesley.bland(a)intel.com> wrote: > Hi all, > > I think we're still on hold for the ULFM data resilience discussion until > we're able to get some more feedback from Jeff and our non-ULFM topics are > ready for another discussion with the rest of the forum. > > Are there other topics that people want to discuss tomorrow or should we > cancel the call? > > Thanks, > Wesley > _______________________________________________ > mpiwg-ft mailing list > mpiwg-ft(a)lists.mpi-forum.org > https://lists.mpi-forum.org/mailman/listinfo/mpiwg-ft > -- Jeff Hammond jeff.science(a)gmail.com http://jeffhammond.github.io/

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Re: [mpiwg-ft] Subjects for Tomorrow's FTWG Call
by Ignacio Laguna 31 Oct '17

31 Oct '17

I cannot make the call tomorrow anyway (but can call on the next one, Nov/8). Ignacio On 10/31/17 1:03 PM, Bland, Wesley wrote: > Hi all, > > I think we're still on hold for the ULFM data resilience discussion until we're able to get some more feedback from Jeff and our non-ULFM topics are ready for another discussion with the rest of the forum. > > Are there other topics that people want to discuss tomorrow or should we cancel the call? > > Thanks, > Wesley > _______________________________________________ > mpiwg-ft mailing list > mpiwg-ft(a)lists.mpi-forum.org > https://lists.mpi-forum.org/mailman/listinfo/mpiwg-ft

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Subjects for Tomorrow's FTWG Call
by Bland, Wesley 31 Oct '17

31 Oct '17

Hi all, I think we're still on hold for the ULFM data resilience discussion until we're able to get some more feedback from Jeff and our non-ULFM topics are ready for another discussion with the rest of the forum. Are there other topics that people want to discuss tomorrow or should we cancel the call? Thanks, Wesley

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Canceled: Fault Tolerance Working Group Con Call
by Bland, Wesley 25 Oct '17

25 Oct '17

When: Wednesday, October 25, 2017 4:00 PM-5:00 PM. UTC Where: Zoom *~*~*~*~*~*~*~*~*~* Weekly con call to discuss Fault Tolerance Topics as they relate to the MPI Standard. I’ll try to update the agenda before the call weekly (as opposed to the old way of sending a reminder email). === Join from PC, Mac, Linux, iOS or Android: https://tennessee.zoom.us/j/632356722?pwd=lI4%2F169CGcewIumekTziMw%3D%3D Password: mpiforum Or iPhone one-tap (US Toll): +14086380968,632356722# or +16465588656,632356722# Or Telephone: Dial: +1 408 638 0968 (US Toll) or +1 646 558 8656 (US Toll) Meeting ID: 632 356 722 International numbers available: https://tennessee.zoom.us/zoomconference?m=GscM59o_Qoig8v4aJl1OrsnXL-7Blrke Or an H.323/SIP room system: H.323: 162.255.37.11 (US West) or 162.255.36.11 (US East) Meeting ID: 632 356 722 Password: 366244 SIP: 632356722(a)zoomcrc.com Password: 366244

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Fault Tolerance Working Group Con Call
by Bland, Wesley 25 Oct '17

25 Oct '17

As discussed last week, we're in a bit of a holding pattern right now on ULFM while we get some feedback on the RMA section, so I don't think we have enough topics today to hold the call. Let's wait until next week and try again. Thanks, Wesley

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FTWG 2017-10-18 Notes
by Bland, Wesley 19 Oct '17

19 Oct '17

The notes from the meeting are now posted: https://github.com/mpiwg-ft/ft-issues/wiki/2017-10-18 Thanks, Wesley === ### Attendees * Intel - Wesley, Jim * UTK - Aurelien * ORNL - Geoffroy * Argonne - Yanfei, Ken * Sandia - Keita * LLNL - Murali, Ignacio ## RMA Fault Tolerance (Data Resilience) [Link to pull request](https://github.com/mpiwg-ft/mpi-standard/pull/4) Continued discussion of whether this work is useful. * Aurelien - The description of the failure model is unclear. We need to better differentiate between `MPI_ERR_PROC_FAILED` and `MPI_ERR_DATA_UNAVAILABLE`. * Jim - Should `MPI_ERR_DATA_UNAVAILABLE` be usable outside of RMA? Does it apply to point-to-point or collectives? * Jim/Aurelien - Is the justification for this work that flush doesn't allow detection of process failure? They're still not convinced that this is true. * As long as flush can complete successfully, do we really need to tell you if a process failed on the other end? * Jim - On the other hand, it might be true that we can't guarantee any process failure detection in _any_ RMA operation. Maybe we should just not allow process failure errors (as opposed to "upgrading" other types of errors to process failure). * Jim - One place this still makes sense as is is having a process with data corrupted because another process failed during a put. If a third process is reading the bad memory, it _could_ get `MPI_ERR_DATA_UNAVAILABLE` instead of `MPI_ERR_PROC_FAILED`. ### Bottom Line * We're still unclear on the failure model expected here. We probably need to get more feedback from Jeff. * We also aren't convinced that process failure semantics aren't sufficient to tell the user all of the actionable information that they need. ## For next week: * Get feedback from Jeff when he comes back from paternity leave. ## In the future: * Start discussing text for FA-MPI and Reinit.

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Fault Tolerance Working Group Con Call
by Bland, Wesley 19 Oct '17

19 Oct '17

When: Wednesday, October 18, 2017 4:00 PM-5:00 PM. UTC Where: Zoom *~*~*~*~*~*~*~*~*~* Agenda: * Continue discussion of MPI_ERR_DATA_UNAVAILABLE === Join from PC, Mac, Linux, iOS or Android: https://tennessee.zoom.us/j/632356722?pwd=lI4%2F169CGcewIumekTziMw%3D%3D Password: mpiforum Or iPhone one-tap (US Toll): +14086380968,632356722# or +16465588656,632356722# Or Telephone: Dial: +1 408 638 0968 (US Toll) or +1 646 558 8656 (US Toll) Meeting ID: 632 356 722 International numbers available: https://tennessee.zoom.us/zoomconference?m=GscM59o_Qoig8v4aJl1OrsnXL-7Blrke Or an H.323/SIP room system: H.323: 162.255.37.11 (US West) or 162.255.36.11 (US East) Meeting ID: 632 356 722 Password: 366244 SIP: 632356722(a)zoomcrc.com Password: 366244

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2017 10 11 · mpiwg-ft/ft-issues Wiki
by Bland, Wesley 11 Oct '17

11 Oct '17

The notes for today's call are available on the wiki. > https://github.com/mpiwg-ft/ft-issues/wiki/2017-10-11 <https://github.com/mpiwg-ft/ft-issues/wiki/2017-10-11> A badly formatted version is copied below. Thanks, Wesley === Attendees • Intel - Wesley • ORNL - Geoffroy • Argonne - Yanfei, Ken • Auburn - Nawrin • Sandia - Keita • UTC - Tony RMA Fault Tolerance (Data Resilience) Link to pull request - https://github.com/mpiwg-ft/mpi-standard/pull/4 Summary of previous discussion • Jeff - RMA is different from communicator-based FT because it is more data focused and it is more expensive and less likely to detect process failure. We should add more text to focus on conveying that the data is unavailable. • Others - This is a bit out of scope of the initial ULFM proposal but still important. Maybe this should be an accompanying proposal Discussion on today's call • Wesley - After reading through the proposal again, I think it makes sense to bring this into ULFM proper. It completes the picture for RMA because if we can detect process failure, we do, but we can also express failure in other, cheaper ways. • Keita - The expected recovery model is unclear here. • Good point: Need to add some advice to say that we expect the user to free the window, fix the data and recreate the window. They may or may not discover a process failure during this procedure. • Wesley - The advice about MPI_WIN_FREE needs to be expanded to cover MPI_DATA_UNAVAILABLE around lines 418-419. ULFM Aurelien merged the proposal to detect when a communicator is revoked. This is now part of ULFM proper. For next week: • All - Go over the MPI_ERR_DATA_UNAVAILABLE proposal text and leave comments. Specifically look at new text proposals in the comments.

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Fault Tolerance Working Group Con Call
by Bland, Wesley 11 Oct '17

11 Oct '17

When: Wednesday, October 11, 2017 4:00 PM-5:00 PM. Greenwich Standard Time Where: Zoom *~*~*~*~*~*~*~*~*~* Agenda: * Continue discussion of RMA for ULFM * Other topics === Join from PC, Mac, Linux, iOS or Android: https://tennessee.zoom.us/j/632356722?pwd=lI4%2F169CGcewIumekTziMw%3D%3D Password: mpiforum Or iPhone one-tap (US Toll): +14086380968,632356722# or +16465588656,632356722# Or Telephone: Dial: +1 408 638 0968 (US Toll) or +1 646 558 8656 (US Toll) Meeting ID: 632 356 722 International numbers available: https://tennessee.zoom.us/zoomconference?m=GscM59o_Qoig8v4aJl1OrsnXL-7Blrke Or an H.323/SIP room system: H.323: 162.255.37.11 (US West) or 162.255.36.11 (US East) Meeting ID: 632 356 722 Password: 366244 SIP: 632356722(a)zoomcrc.com Password: 366244

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