Thanks for that Jeff. Are you referring to this discussion? http://lists.mpich.org/pipermail/devel/2016-July/000717.html If so, that shares some similarity with what I’m trying to recreate in MPICH. However, our code using MPICH2 makes no use whatsoever of mpiexec when in “connect/accept” mode, and I changing this would be rather invasive. It seems as though that open issue has been open for quite a while now, with no scheduled release for when it might be addressed – so am I correct in understanding that there are no known workarounds, and that essentially my only option for now is to stick with MPICH2? Cheers, Edric. From: Jeff Hammond [mailto:[email protected]] Sent: Monday, August 01, 2016 6:43 PM To: MPICH <[email protected]> Subject: Re: [mpich-discuss] Singleton init configuration for MPICH It's an open issue: https://trac.mpich.org/projects/mpich/ticket/1074. There was some discussion on the devel list as of last week that might be of interest to you. Jeff On Mon, Aug 1, 2016 at 8:47 AM, Edric Ellis <[email protected]<mailto:[email protected]>> wrote: Hi, I need to come up with an MPICH build that allows singleton-init processes to use MPI_Comm_connect/accept to get connected. Our MPICH2 build uses the “smpd” process manager to achieve this. However, now that we’re upgrading to MPICH (3.1.4), I notice that the “smpd” process manager no longer exists. Is there a combination of process manager and PMI that allows connect/accept for singleton-init processes? I’ve tried a few things and cannot seem to find a combination that works. Here are the things I’ve tried: 1. Hydra with pmi=simple – fails when attempting to launch hydra’s mpiexec (I don’t have the message to hand, but my recollection is that hydra’s mpiexec didn’t accept “-pmi_args”) 2. Hydra with pmi=pmi2/simple – cannot be built 3. Gforker with pmi=pmi2/simple – required a couple of tweaks before it could be built, and then fails in PMPI_Init_thread complaining “Message truncated” Is there some other combination that might work? Ideally, the singleton-init processes wouldn’t need to use mpiexec at all (as was the case with our MPICH2 build using smpd). Cheers, Edric. _______________________________________________ discuss mailing list [email protected]<mailto:[email protected]> To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss -- Jeff Hammond [email protected]<mailto:[email protected]> http://jeffhammond.github.io/ _______________________________________________ discuss mailing list [email protected] To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss