Thanks for the clarification - very interesting indeed! I'll look at it more closely.
On Apr 17, 2013, at 9:20 AM, George Bosilca <bosi...@icl.utk.edu> wrote: > On Apr 16, 2013, at 15:51 , Ralph Castain <r...@open-mpi.org> wrote: > >> Just curious: I thought ULFM dealt with recovering an MPI job where one or >> more processes fail. Is this correct? > > It depends what is the definition of "recovering" you take. ULFM is about > leaving the processes that remains (after a fault or a disconnect) in a state > that allow them to continue to make progress. It is not about recovering > processes, or user data, but it does provide the minimalistic set of > functionalities to allow application to do this, if needed (revoke, agreement > and shrink). > >> HLA/RTI consists of processes that start at random times, run to completion, >> and then exit normally. While a failure could occur, most process >> terminations are normal and there is no need/intent to revive them. > > As I said above, there is no revival of processes in ULFM, and it was never > our intent to have such feature. The dynamic world is to be constructed using > MPI-2 constructs (MPI_Spawn or MPI_Connect/Accept or even MPI_Join). > >> So it's mostly a case of massively exercising MPI's dynamic >> connect/accept/disconnect functions. >> >> Do ULFM's structures have some utility for that purpose? > > Absolutely. If the process that leaves instead of calling MPI_Finalize calls > exit() this will be interpreted by the version of the runtime in ULFM as an > event triggering a report. All the ensuing mechanisms are then activated and > the application can react to this event with the most meaningful approach it > can envision. > > George. > >> >> >> On Apr 16, 2013, at 3:20 AM, George Bosilca <bosi...@icl.utk.edu> wrote: >> >>> There is an ongoing effort to address the potential volatility of processes >>> in MPI called ULFM. There is a working version available at >>> http://fault-tolerance.org. It supports TCP, sm and IB (mostly). You will >>> find some examples, and the document explaining the additional constructs >>> needed in MPI to achieve this. >>> >>> George. >>> >>> On Apr 15, 2013, at 17:29 , John Chludzinski <john.chludzin...@gmail.com> >>> wrote: >>> >>>> That would seem to preclude its use for an RTI. Unless you have a card up >>>> your sleeve? >>>> >>>> ---John >>>> >>>> >>>> On Mon, Apr 15, 2013 at 11:23 AM, Ralph Castain <r...@open-mpi.org> wrote: >>>> It isn't the fact that there are multiple programs being used - we support >>>> that just fine. The problem with HLA/RTI is that it allows programs to >>>> come/go at will - i.e., not every program has to start at the same time, >>>> nor complete at the same time. MPI requires that all programs be executing >>>> at the beginning, and that all call finalize prior to anyone exiting. >>>> >>>> >>>> On Apr 15, 2013, at 8:14 AM, John Chludzinski <john.chludzin...@gmail.com> >>>> wrote: >>>> >>>>> I just received an e-mail notifying me that MPI-2 supports MPMD. This >>>>> would seen to be just what the doctor ordered? >>>>> >>>>> ---John >>>>> >>>>> >>>>> On Mon, Apr 15, 2013 at 11:10 AM, Ralph Castain <r...@open-mpi.org> wrote: >>>>> FWIW: some of us are working on a variant of MPI that would indeed >>>>> support what you describe - it would support send/recv (i.e., MPI-1), but >>>>> not collectives, and so would allow communication between arbitrary >>>>> programs. >>>>> >>>>> Not specifically targeting HLA/RTI, though I suppose a wrapper that >>>>> conformed to that standard could be created. >>>>> >>>>> On Apr 15, 2013, at 7:50 AM, John Chludzinski >>>>> <john.chludzin...@gmail.com> wrote: >>>>> >>>>> > This would be a departure from the SPMD paradigm that seems central to >>>>> > MPI's design. Each process would be a completely different program >>>>> > (piece of code) and I'm not sure how well that would working using >>>>> > MPI? >>>>> > >>>>> > BTW, MPI is commonly used in the parallel discrete even world for >>>>> > communication between LPs (federates in HLA). But these LPs are >>>>> > usually the same program. >>>>> > >>>>> > ---John >>>>> > >>>>> > On Mon, Apr 15, 2013 at 10:22 AM, John Chludzinski >>>>> > <john.chludzin...@gmail.com> wrote: >>>>> >> Is anyone aware of an MPI based HLA/RTI (DoD High Level Architecture >>>>> >> (HLA) / Runtime Infrastructure)? >>>>> >> >>>>> >> ---John >>>>> > _______________________________________________ >>>>> > users mailing list >>>>> > us...@open-mpi.org >>>>> > http://www.open-mpi.org/mailman/listinfo.cgi/users >>>>> >>>>> >>>>> _______________________________________________ >>>>> users mailing list >>>>> us...@open-mpi.org >>>>> http://www.open-mpi.org/mailman/listinfo.cgi/users >>>>> >>>>> _______________________________________________ >>>>> users mailing list >>>>> us...@open-mpi.org >>>>> http://www.open-mpi.org/mailman/listinfo.cgi/users >>>> >>>> >>>> _______________________________________________ >>>> users mailing list >>>> us...@open-mpi.org >>>> http://www.open-mpi.org/mailman/listinfo.cgi/users >>>> >>>> _______________________________________________ >>>> users mailing list >>>> us...@open-mpi.org >>>> http://www.open-mpi.org/mailman/listinfo.cgi/users >>> >>> _______________________________________________ >>> users mailing list >>> us...@open-mpi.org >>> http://www.open-mpi.org/mailman/listinfo.cgi/users >> >> _______________________________________________ >> users mailing list >> us...@open-mpi.org >> http://www.open-mpi.org/mailman/listinfo.cgi/users > > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users
