On Tue, 9 May 2017 00:30:38 +0200 Reuti <re...@staff.uni-marburg.de> wrote: > Hi, > > Am 08.05.2017 um 23:25 schrieb David Niklas: > > > Hello, > > I originally ported this question at LQ, but the answer I got back > > shows rather poor insight on the subject of MPI, so I'm taking the > > liberty of posting here also. > > > > https://www.linuxquestions.org/questions/showthread.php?p=5707962 > > > > What I'm trying to do is figure out how/what to use to update an osm > > file (open street map), in a cross system manner. I know the correct > > program osmosis and for de/re-compression lbzip2 but how to do this > > across computers is confusing me, even after a few hours of searching > > online. > > lbzip2 is only thread parallel on a single machine. With pbzip2 you > mention it's the same, but it exists an MPI version MPIBZIP2 - I can't find the project, do you have a link?
> unfortunately it looks unmaintained since 2007. Maybe you can contact > the author about its state. Without an MPI application like this, the > MPI library is nothing on its own which would divide and distribute one > task to several machines automatically. Well, there might be other ways to cause a program to run on multiple computers. Perhaps a virtual machine made of of multiple physical machines? > osmosis itself seems to run in serial only (they don't say any word > whether it uses any parallelism). Yes, it does run multiple threads, you just start another task (and add a buffer). I tested this on my machine, I think it is --read-xml --write-xml and --read-xml-change that start new threads. The question is whether or not java is naively MPI aware or does the app need special coding? > For the intended task the only option is to use a single machine with > as many cores as possible AFAICS. Though about that, and it is doable with respect to memory and disk constraints, the problem is that it would take a *long* time esp. with the amount of updates I must do, hence my inquiry. Thanks, David _______________________________________________ users mailing list users@lists.open-mpi.org https://rfd.newmexicoconsortium.org/mailman/listinfo/users
