The embedded Singularity support hasn’t made it into the OMPI 2.x release series yet, though OMPI will still work within a Singularity container anyway.
Compatibility across the container boundary is always a problem, as your examples illustrate. If the system is using one OMPI version and the container is using another, then the only concern is compatibility across the container boundary of the process-to-ORTE daemon communication. In the OMPI 2.x series and beyond, this is done with PMIx. OMPI v2.0 is based on PMIx v1.x, and so will OMPI v2.1. Thus, there is no compatibility issue there. However, that statement is _not_ true for OMPI v1.10 and earlier series. Future OMPI versions will utilize PMIx v2 and above, which include a cross-version compatibility layer. Thus, you shouldn’t have any issues mixing and matching OMPI versions from this regard. However, your second example is a perfect illustration of where containerization can break down. If you build your container on a system that doesn’t have (for example) tm and verbs installed on it, then those OMPI components will not be built. The tm component won’t matter as the system version of mpirun will be executing, and it presumably knows how to interact with Torque. However, if you run that container on a system that has verbs, your application won’t be able to utilize the verbs support because those components were never compiled. Note that the converse is not true: if you build your container on a system that has verbs installed, you can then run it on a system that doesn’t have verbs support and those components will dynamically disqualify themselves. Remember, you only need the verbs headers to be installed - you don’t have to build on a machine that actually has a verbs-supporting NIC installed (this is how the distributions get around the problem). Thus, it isn’t hard to avoid this portability problem - you just need to think ahead a bit. HTH Ralph > On Feb 17, 2017, at 3:49 PM, Bennet Fauber <ben...@umich.edu> wrote: > > I am wishing to follow the instructions on the Singularity web site, > > http://singularity.lbl.gov/docs-hpc > > to test Singularity and OMPI on our cluster. My previously normal > configure for the 1.x series looked like this. > > ./configure --prefix=/usr/local \ > --mandir=${PREFIX}/share/man \ > --with-tm --with-verbs \ > --disable-dlopen --enable-shared > CC=gcc CXX=g++ FC=gfortran > > I have a couple of wonderments. > > First, I presume it will be best to have the same version of OMPI > inside the container as out, but how sensitive will it be to minor > versions? All 2.1.x version should be fine, but not mix 2.1.x outside > with 2.2.x inside or vice-versa (might be backward compatible but not > forward)? > > Second, if someone builds OMPI inside their container on an external > system, without tm and verbs, then brings the container to our system, > will the tm and verbs be handled by the calling mpirun from the host > system, and the OMPI inside the container won't care? Will not having > those inside the container cause them to be suppressed outside? > > Thanks in advance, -- bennet > _______________________________________________ > users mailing list > users@lists.open-mpi.org > https://rfd.newmexicoconsortium.org/mailman/listinfo/users _______________________________________________ users mailing list users@lists.open-mpi.org https://rfd.newmexicoconsortium.org/mailman/listinfo/users
