[mvapich-discuss] Rank Placement in MVAPICH

[Hari Subramoni]

Hi Vaibhav,

Oh yeah, I see it now

> compute-0-3-local

Glad to know that things are working fine for you now.

Thx,
Hari.


On Mon, 11 Apr 2011, vaibhav dutt wrote:

> Hi,
>
> Thanks for your help.Actually there was an error in my hostfile as pointed
> by Dan.
> After changing that, it started working.
>
> Thanks
>
> On Mon, Apr 11, 2011 at 8:16 AM, Hari Subramoni <subramon at cse.ohio-state.edu
> > wrote:
>
> > Hi Vaibhav,
> >
> > Which job launcher are you using? I'm assuming that you are using
> > mpirun_rsh. If so, your hostfile ordering seems proper to launch the job
> > with a block ordering of ranks.
> >
> > Do you have password-less ssh set up between the node you are launching
> > your MPI job from and all the nodes specified in your hostfile?
> >
> > What application are you trying to run here? Can you try running a simple
> > application such as 'cpi' available under the examples sub-directory of
> > the MVAPICH2 source files. This will allow us to eliminate application
> > errors.
> >
> > Also, I just saw that you'd mentioned 'MVAPICH' in the subject line. This
> > is an older release which does not have a lot of the latest bug fixes and
> > performance enhancements we have been doing. We recommend that you switch
> > to MVAPICH2 to get the best performance and the latest bug fixes. You can
> > download the tarball containing the latest release of MVAPICH2 from the
> > following site
> >
> > http://mvapich.cse.ohio-state.edu/download/mvapich2/
> >
> > Thx,
> > Hari.
> >
> >
> > On Fri, 8 Apr 2011, vaibhav dutt wrote:
> >
> > > Hi,
> > >
> > > I tried to change the hostfile in this manner but I am getting an error
> > like
> > >
> > >
> > >  child_handler: Error in init phase...wait for cleanup! (0/5mpispawn
> > > connections)
> > > Failed in initilization phase, cleaned up all the mpispawn!
> > >
> > >
> > > I am trying to run 32 processes across 4 nodes and my hostfile looks like
> > >
> > >
> > > compute-0-0.local
> > > compute-0-0.local
> > > compute-0-0.local
> > > compute-0-0.local
> > > compute-0-0.local
> > > compute-0-0.local
> > > compute-0-0.local
> > > compute-0-0.local
> > > compute-0-1.local
> > > compute-0-1.local
> > > compute-0-1.local
> > > compute-0-1.local
> > > compute-0-1.local
> > > compute-0-1.local
> > > compute-0-1.local
> > > compute-0-1.local
> > > compute-0-2.local
> > > compute-0-2.local
> > > compute-0-2.local
> > > compute-0-2.local
> > > compute-0-2.local
> > > compute-0-2.local
> > > compute-0-2.local
> > > compute-0-2.local
> > > compute-0-3.local
> > > compute-0-3-local
> > > compute-0-3.local
> > > compute-0-3.local
> > > compute-0-3.local
> > > compute-0-3.local
> > > compute-0-3.local
> > > compute-0-3.local
> > >
> > > Thanks
> > > On Thu, Apr 7, 2011 at 12:56 PM, Hari Subramoni <
> > subramon at cse.ohio-state.edu
> > > > wrote:
> > >
> > > > Hi Vaibhav,
> > > >
> > > > To get a block allocation just repeat n1 8 times then n2 8 times in
> > your
> > > > hostfile. This will change the allocation to block.
> > > >
> > > > 1: n1
> > > > 2: n1
> > > > ..
> > > > 8: n1
> > > > 1: n2
> > > > 2: n2
> > > > ..
> > > > 8: n2
> > > >
> > > > Please refer to the MVAPICH2 userguide at the following link for more
> > > > information
> > > >
> > > >
> > > >
> > http://mvapich.cse.ohio-state.edu/support/user_guide_mvapich2-1.6.html#x1-240005.2.1
> > > >
> > > > Thx,
> > > > Hari.
> > > >
> > > >
> > > > On Thu, 7 Apr 2011, vaibhav dutt wrote:
> > > >
> > > > > Hi,
> > > > >
> > > > > I am trying to execute a job  of 16 processes across two nodes and my
> > > > > hostfile looks like
> > > > >
> > > > > n1:8
> > > > > n2:8.
> > > > >
> > > > > I notice that the ranks   0,2,4,6,8,10,12,14 are on node 1 and
> > > > > 1,3,5,7,9,11,13,15 are on node 2 which seems to be
> > > > > cyclic distribution. Is this the default rank placement strategy in
> > > > MVAPICH
> > > > > as I did not give any special option on runtime
> > > > > for the rank distribution to be cyclic. How to change it to block?
> > > > >
> > > > > Thanks
> > > > >
> > > >
> > > >
> > >
> >
> >
>