On Jan 22, 11:26 am, Dima Pasechnik <dimp...@gmail.com> wrote: > On Jan 22, 5:32 pm, Mikael Vejdemo Johansson <michiex...@gmail.com> > wrote: > > > Yeah, Parallel Python looks really neat. However, I actually use quite > > a bit of the inter-process communication parts of MPI in my code; and > > PP doesn't seem to have as useful primitives for that. > > > Is there really no sensible way to use OpenMPI and Sage on more than > > one computer? > > Do you use mpi4py spkg? >
This is exactly what I'm using, and I'm also using the openmpi spkg. Furthermore, because of the infrastructure of the computers I'm trying to use, the sysadmin is reluctant to install OpenMPI on the systems themselves — and so I was really deeply hoping to be able to use the OpenMPI that comes with Sage directly. > Apparently, it can be run on a cluster (just as a python tool). > In python, you can do > from sage.all import * > (provided it knows about sage, e.g. when your python is just "sage - > python") > > Hence it should also work with sage, if it works without it... > > Well, this is mostly guessing on my side :-) > > This is exactly how I use sage from my scripts. mpi4py for IPC, and from sage.all import * to get hold of the computational algebra routines I need. // Mikael > > > On Jan 22, 1:37 am, Dima Pasechnik <dimp...@gmail.com> wrote: > > > > Hi Mikael, > > > I'd have looked into using Parallel Python > > > (http://www.parallelpython.com/) > > > which is just a Python library. > > > If it worked with Sage, it would be a worthwhile addition to Sage > > > packages... > > > > Lately there is an ongoing project to make Sage notebook well- > > > scalable, but I do not know > > > if parallel code execution came into consideration. > > > > On Jan 21, 9:49 pm, Mikael Vejdemo Johansson <michiex...@gmail.com> > > > wrote: > > > > > In the course of working on an idea for parallel and distributed > > > > Gröbner bases, I have an example implementation of the idea using Sage > > > > for the commutative algebra routines. This has been — mainly — very > > > > pleasant, with the ease of calling Sage from Python, and with the ease > > > > of using the included (optional) SQLAlchemy, MPI4Py and OpenMPI > > > > packages. > > > > > However, I now find myself in the situation where I need to go to > > > > several computational nodes, and not only several cores on a single > > > > node. And I am getting some problems that I'd need advice for. > > > > > Using OpenMPI across several nodes is easy. It will, given easy enough > > > > shell scripts and specification files, ssh to each node and launch > > > > processes there, and take care of all process enumeration and > > > > communication issues. However, especially when using the OpenMPI > > > > included with Sage, there is a bit of a chicken vs. egg problem. The > > > > shell created by ssh to a new node will not automatically be in a Sage > > > > shell environment; but the OpenMPI I'm using sits inside Sage. It > > > > doesn't seem like the »sage -sh« command necessarily takes an optional > > > > command to run afterwards — so I can't have OpenMPI do something like > > > > ssh nextnode 'sage -sh mpirun -np $NP $COMMAND' > > > > > Looking through the mailing list archives, I have found one > > > > discussion, in which DSage was suggested for anyone _actually_ wanting > > > > to run Sage in a cluster context, and then a few years later, another > > > > discussion removing DSage from the system due to non-use. Is there > > > > _anything_ I can do to make my computation work at this point? -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
