I don't quite understand your architecture enough to answer your question. E.g., someone pointed out to me off-list that if you only have 1 listener, a send is effectively the same thing as a broadcast (for which you could test/wait on a non-blocking receive, for example).
MPI broadcasts only work on fixed communicators -- meaning that you effectively have to know the root and the receivers ahead of time. If the receivers don't know who the root will be beforehand, that's unfortunately not a good match for the MPI_Bcast operation. On May 3, 2011, at 4:07 AM, Randolph Pullen wrote: > > From: Randolph Pullen <randolph_pul...@yahoo.com.au> > Subject: Re: Re: [OMPI users] is there an equiv of iprove for bcast? > To: us...@open-mpi.or > Received: Monday, 2 May, 2011, 12:53 PM > > Non blocking Bcasts or tests would do it. > I currently have the clearing-house solution working but it is unsatisfying > because of its serial node. - As it scales it will overload this node. > > The problem rephrased: > Instead of n*2 processes, I am having to use n*2+1 with the extra process > serially receiving listener messages on behalf of the workers before > transmitting these messages to workers in its comm_group. > > Is there a way to Bcast directly from each listener to the worker pool? > (listeners must monitor their ports most of the time and cant participate in > global bcasts) > Not knowing which listener is going to transmit prevents the correct > comm_group being used with Bcast calls. > > --- On Sat, 30/4/11, Jeff Squyres <jsquy...@cisco.com> wrote: > > From: Jeff Squyres <jsquy...@cisco.com> > Subject: Re: [OMPI users] is there an equiv of iprove for bcast? > To: randolph_pul...@yahoo.com.au, "Open MPI Users" <us...@open-mpi.org> > Received: Saturday, 30 April, 2011, 7:17 AM > > On Apr 29, 2011, at 1:21 AM, Randolph Pullen wrote: > > > I am having a design issue: > > My server application has 2 processes per node, 1 listener and 1 worker. > > Each listener monitors a specified port for incoming TCP connections with > > the goal that on receipt of a request it will distribute it over the > > workers in a SIMD fashion. > > > > My problem is this: how can I get the workers to accept work from any of > > the listeners? > > Making a separate communicator does not help as the sender is unknown. > > Other than making a serial 'clearing house' process I cant think of a way > > - Iprobe for Bcast would be useful. > > I'm not quite sure I understand your question. > > There currently is no probe for collectives, but MPI-3 has non-blocking > collectives which you could MPI_Test for. There's a 3rd party library > implementation called libNBC (non-blocking collectives) that you could use > until such things become natively available. > > -- > Jeff Squyres > jsquy...@cisco.com > For corporate legal information go to: > http://www.cisco.com/web/about/doing_business/legal/cri/ > > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users -- Jeff Squyres jsquy...@cisco.com For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/
