June 2019 - mpiwg-ft - mailman3.cels.anl.gov

Re: [mpiwg-ft] help with advice to implementors accompanying MPI_Abort
by HOLMES Daniel 26 Jun '19

26 Jun '19

Hi Aurélien, My concern with changing this text to refer to a different communicator was that the user might have to set an error handler on MPI_COMM_WORLD in addition to the one on that (sub)communicator - to avoid MPI just aborting all MPI processes in MCW at the first sign of trouble. The first sentence says “high quality implementation should” so maybe there is no reason to worry here. We will drop this item from our to-do list. Thanks! Cheers, Dan. — Dr Daniel Holmes PhD Applications Consultant in HPC Research d.holmes(a)epcc.ed.ac.uk<mailto:[email protected]> Phone: +44 (0) 131 651 3465 Mobile: +44 (0) 7940 524 088 Address: Room 2.09, Bayes Centre, 47 Potterrow, Central Area, Edinburgh, EH8 9BT — The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336. — On 25 Jun 2019, at 19:33, Aurelien Bouteiller via mpiwg-ft <mpiwg-ft(a)lists.mpi-forum.org<mailto:[email protected]>> wrote: It does not appear to me that any change is necessary. The only part about MPI_COMM_WORLD is in an 'as an example' clause. That being said, substituting MPI_COMM_WORLD with some generic 'communicator comm' would also work. Aurelien On Tue, Jun 25, 2019 at 9:49 AM Pritchard Jr., Howard via mpiwg-ft <mpiwg-ft(a)lists.mpi-forum.org<mailto:[email protected]>> wrote: Hello MPI FTer’s, The Sessions WG could use some help/suggestions about how to adjust the following advice to implementors that accompanies the definition of MPI_Abort: \begin{implementors} After aborting a subset of processes, a high quality implementation should be able to provide error handling for communicators, windows, and files involving both aborted and non-aborted processes. As an example, if the user changes the error handler for \const{MPI\_COMM\_WORLD} to \const{MPI\_ERRORS\_RETURN} or a custom error handler, when a subset of \const{MPI\_COMM\_WORLD} is aborted, the remaining processes in \const{MPI\_COMM\_WORLD} should be able to continue communicating with each other and receive appropriate error codes when attempting communication with an aborted process. \end{implementors} We would like to generalize this advice to implementors to the case where MPI_COMM_WORLD isn’t a valid communicator, i.e. when an application is using the Sessions model. We think that there would need to be some reworking of the existing text to cover the sessions use case. Since the FT group has worked quite a bit on this text, we’d defer to your group for suggestions on how to generalize this text to cover the sessions use case. Thanks very much for any help, Howard -- Howard Pritchard HPC-ENV Los Alamos National Laboratory _______________________________________________ mpiwg-ft mailing list mpiwg-ft(a)lists.mpi-forum.org<mailto:[email protected]> https://lists.mpi-forum.org/mailman/listinfo/mpiwg-ft _______________________________________________ mpiwg-ft mailing list mpiwg-ft(a)lists.mpi-forum.org<mailto:[email protected]> https://lists.mpi-forum.org/mailman/listinfo/mpiwg-ft

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Re: [mpiwg-ft] help with advice to implementors accompanying MPI_Abort
by Aurelien Bouteiller 25 Jun '19

25 Jun '19

It does not appear to me that any change is necessary. The only part about MPI_COMM_WORLD is in an 'as an example' clause. That being said, substituting MPI_COMM_WORLD with some generic 'communicator comm' would also work. Aurelien On Tue, Jun 25, 2019 at 9:49 AM Pritchard Jr., Howard via mpiwg-ft < mpiwg-ft(a)lists.mpi-forum.org> wrote: > Hello MPI FTer’s, > > > > The Sessions WG could use some help/suggestions about how to adjust the > following advice to implementors that accompanies the definition of > MPI_Abort: > > > > \begin{implementors} > > After aborting a subset of processes, a high quality implementation > should > > be able to provide error handling for communicators, windows, and > files > > involving both aborted and non-aborted processes. As an example, if > the > > user changes the error handler for \const{MPI\_COMM\_WORLD} to > > \const{MPI\_ERRORS\_RETURN} or a custom error handler, when a subset > of > > \const{MPI\_COMM\_WORLD} is aborted, the remaining processes in > > \const{MPI\_COMM\_WORLD} should be able to continue communicating > with each > > other and receive appropriate error codes when attempting > communication > > with an aborted process. > > \end{implementors} > > > > We would like to generalize this advice to implementors to the case where > MPI_COMM_WORLD isn’t a valid communicator, i.e. when an application is > using the Sessions model. > > We think that there would need to be some reworking of the existing text > to cover the sessions use case. Since the FT group has worked quite a bit > on this text, we’d defer to your group for suggestions on how to generalize > this text to cover the sessions use case. > > > > Thanks very much for any help, > > > > Howard > > > > -- > > > > Howard Pritchard > > HPC-ENV > > Los Alamos National Laboratory > > > _______________________________________________ > mpiwg-ft mailing list > mpiwg-ft(a)lists.mpi-forum.org > https://lists.mpi-forum.org/mailman/listinfo/mpiwg-ft >

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help with advice to implementors accompanying MPI_Abort
by Pritchard Jr., Howard 25 Jun '19

25 Jun '19

Hello MPI FTer’s, The Sessions WG could use some help/suggestions about how to adjust the following advice to implementors that accompanies the definition of MPI_Abort: \begin{implementors} After aborting a subset of processes, a high quality implementation should be able to provide error handling for communicators, windows, and files involving both aborted and non-aborted processes. As an example, if the user changes the error handler for \const{MPI\_COMM\_WORLD} to \const{MPI\_ERRORS\_RETURN} or a custom error handler, when a subset of \const{MPI\_COMM\_WORLD} is aborted, the remaining processes in \const{MPI\_COMM\_WORLD} should be able to continue communicating with each other and receive appropriate error codes when attempting communication with an aborted process. \end{implementors} We would like to generalize this advice to implementors to the case where MPI_COMM_WORLD isn’t a valid communicator, i.e. when an application is using the Sessions model. We think that there would need to be some reworking of the existing text to cover the sessions use case. Since the FT group has worked quite a bit on this text, we’d defer to your group for suggestions on how to generalize this text to cover the sessions use case. Thanks very much for any help, Howard -- Howard Pritchard HPC-ENV Los Alamos National Laboratory

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FTWG Con Call - 2019-06-10
by Wesley Bland 10 Jun '19

10 Jun '19

The Fault Tolerance Working Group’s weekly con call is today at 12:00 PM Eastern. Today's agenda: * Continue fine and course grained recovery discussions (Aurelien and Ignacio, feel free to contribute details of what you’d like to talk about). If there's something else that people would like to discuss, please just send an email to the WG so we can get it on the agenda. Thanks, Wesley ......................................................................................................................................... Join from PC, Mac, Linux, iOS or Android: https://tennessee.zoom.us/j/632356722?pwd=lI4_169CGcewIumekTziMw Password: mpiforum Or iPhone one-tap (US Toll): +16468769923,632356722# or +16699006833,632356722# Or Telephone: Dial: +1 646 876 9923 (US Toll) +1 669 900 6833 (US Toll) Meeting ID: 632 356 722 International numbers available: https://zoom.us/u/6uINe 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: 364216 SIP: 632356722(a)zoomcrc.com Password: 364216 .........................................................................................................................................

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