Open MPI logo

Open MPI User's Mailing List Archives

  |   Home   |   Support   |   FAQ   |  

This web mail archive is frozen.

This page is part of a frozen web archive of this mailing list.

You can still navigate around this archive, but know that no new mails have been added to it since July of 2016.

Click here to be taken to the new web archives of this list; it includes all the mails that are in this frozen archive plus all new mails that have been sent to the list since it was migrated to the new archives.

Subject: Re: [OMPI users] Dynamic process tutorials?
From: Ralph Castain (rhc_at_[hidden])
Date: 2010-07-12 11:29:45

On Jul 12, 2010, at 9:07 AM, Brian Budge wrote:

> Hi Jody -
> Thanks for the reply. is there a way of "fusing" intercommunicators?
> Let's say I have a higher level node scheduler, and it makes a new
> node available to a COMM that is already running. So the master
> spawns another process for that node. How can the new process
> communicate with the other already started processes?

They can connect/accept via ompi-server - checkout "man ompi-server". You can also have them all rendezvous at a common mpirun if you prefer by using the appropriate mca param to give the required contact info.

> Also, how can you specify with MPI_Comm_spawn/multiple() how do you
> specify IP addresses on which to start the processes?

Look at "man MPI_Comm_spawn"

> If my higher level node scheduler needs to take away a process from my
> COMM, is it good/bad for that node to call MPI_Finalize as it exits?

The entire job will automatically abort if it fails to call Finalize as this is considered an abnormal termination event.

> I would prefer not to use any of the MPI command-line utilities
> (mpirun/mpiexec) if that's possible.

Not possible at the moment. I have provided a patch to another user on this list that made it possible to use ompi-server as a rendezvous point for singletons, but that isn't in any formal release yet.

> Thanks,
> Brian
> On Sat, Jul 10, 2010 at 11:53 PM, jody <jody.xha_at_[hidden]> wrote:
>> Hi Brian
>> When you spawn processes with MPI_Comm_spawn(), one of the arguments
>> will be set to an intercommunicator of thes spawner and the spawnees.
>> You can use this intercommunicator as the communicator argument
>> in the MPI_functions.
>> Jody
>> On Fri, Jul 9, 2010 at 5:56 PM, Brian Budge <brian.budge_at_[hidden]> wrote:
>>> Hi all -
>>> I've been looking at the dynamic process features of mpi-2. I have managed
>>> to actually launch processes using spawn, but haven't seen examples for
>>> actually communicating once these processes are launched. I am additionally
>>> interested in how processes created through multiple spawn calls can
>>> communicate.
>>> Does anyone know of resources that describe these topics? My google-fu must
>>> not be up to par :)
>>> Thanks,
>>> Brian
>>> _______________________________________________
>>> users mailing list
>>> users_at_[hidden]
>> _______________________________________________
>> users mailing list
>> users_at_[hidden]
> _______________________________________________
> users mailing list
> users_at_[hidden]