Yes, you are right. In this case, there will be two separate MPI_COMM_WORLD. Plus, one that covers all the resources (let's say that global MPI_COMM_WORLD). Actually, this kind of setup is very common for multi-physics applications such as fluid-structure interaction. So, is it possible to tight this kind of environment with Catalyst? I am not expert about Catalyst but it seems that there might be a problem in the rendering stage even underlying grids and fields are defined without any problem.
Regards, --ufuk > I'm not sure if this is exactly what the original user is referring to, > but it is possible to have two separate codes communicate using MPI > through the dynamic processes in MPI-2. Essentially, one program starts up > on N processors and begins running and gets an MPI_COMM_WORLD. It then > spawns another executable on M different processors and that new > executable will call MPI_INIT and also get its own MPI_COMM_WORLD. So you > have two, disjoint MPI_COMM_WORLD's that get linked together through a > newly created intercommunicator. > > > I've used this to couple a structural mechanics code to our fluid dynamics > solver for example. It sounds like that is similar to what is being done > here. > > > How that would interact with coprocessing is beyond my knowledge though. > It does sound like an interesting problem and one I would be very curious > to find out the details. > > > Tim > > > ________________________________ > From: ParaView <paraview-boun...@paraview.org> on behalf of Andy Bauer > <andy.ba...@kitware.com> > Sent: Wednesday, May 18, 2016 10:52 AM > To: Ufuk Utku Turuncoglu (BE) > Cc: paraview@paraview.org > Subject: Re: [Paraview] capability of ParaView, Catalyst in distributed > computing environment ... > > Hi, > > I'm a bit confused. MPI_COMM_WORLD is the global communicator and as far > as I'm aware, can't be modified which means there can't be two different > communicators. > > Catalyst can be set to use a specific MPI communicator and that's been > done by at least one code (Code_Saturne). I think they have a multiphysics > simulation as well. > > Cheers, > Andy > > On Wed, May 18, 2016 at 5:22 AM, Ufuk Utku Turuncoglu (BE) > <u.utku.turunco...@be.itu.edu.tr<mailto:u.utku.turunco...@be.itu.edu.tr>> > wrote: > Hi All, > > I just wonder about the capability of ParaView, Catalyst in distributed > computing environment. I have little bit experience in in-situ > visualization but it is hard for me to see the big picture at this point. > So, i decided to ask to the user list to get some suggestion from the > experts. Hypothetically, lets assume that we have two simulation code that > are coupled together (i.e. fluid-structure interaction) and both of them > have their own MPI_COMM_WORLD and run on different processors (model1 runs > on MPI rank 0,1,2,3 and model2 runs on 4,5,6,7). What is the correct > design to create integrated in-situ visualization analysis (both model > contributes to same visualization pipeline) in this case? Do you know any > implementation that is similar to this design? At least, is it possible? > > In this case, the adaptor code will need to access to two different > MPI_COMM_WORLD and it could run on all processor (from 0 to 7) or its own > MPI_COMM_WORLD (i.e. MPI ranks 8,9,10,11). Also, the both simulation code > have its own grid and field definitions (might be handled via defining > different input ports). Does it create a problem in Paraview, Catalyst > side, if the multiblock dataset is used to define the grids of the > components in adaptor. I am asking because some MPI processes (belongs to > adaptor code) will not have data for specific model component due to the > domain decomposition implementation of the individual models. For example, > MPI rank 4,5,6,7 will not have data for model1 (that runs on MPI rank > 0,1,2,3) and 0,1,2,3 will not have data for model2 (that runs on MPI rank > 4,5,6,7). To that end, do i need to collect all the data from the > components? If this is the case, how can i handle 2d decomposition > problem? Because, the adaptor code has no any common grid structure that > fits for all the model components. > > Regards, > > Ufuk Turuncoglu > _______________________________________________ > Powered by www.kitware.com<http://www.kitware.com> > > Visit other Kitware open-source projects at > http://www.kitware.com/opensource/opensource.html > > Please keep messages on-topic and check the ParaView Wiki at: > http://paraview.org/Wiki/ParaView > > Search the list archives at: http://markmail.org/search/?q=ParaView > > Follow this link to subscribe/unsubscribe: > http://public.kitware.com/mailman/listinfo/paraview > > _______________________________________________ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the ParaView Wiki at: http://paraview.org/Wiki/ParaView Search the list archives at: http://markmail.org/search/?q=ParaView Follow this link to subscribe/unsubscribe: http://public.kitware.com/mailman/listinfo/paraview