[petsc-users] debugging with no X11 available

[Satish Balay]

If you just need any one node with the debugger - you can do:

mpiexec -n 4 ./ex2 -start_in_debugger noxterm -debugger_node 0 [or 1 or 2 or 3]

If you need to use a debugger on multiple nodes - you'll have
to figure out if you can start your parallel job with multiple
commands [from multiple terminals].

Satish

On Mon, 12 Dec 2011, Dominik Szczerba wrote:

> Thanks for your answers. Meanwhile I clarified the situation a bit:
> 
> I can bring xterm up manually from the command line, but the job is
> run using a scheduler (slurm). It then gets executed on arbitrary
> nodes (some stripped down linux) which apparently can not make X11
> connections.
> Of course, they have their own debugging environment, but I just do
> not want to learn it now. The admins are unable to help me more. I
> tried running the debugger explicitly:
> 
> aprun -n 2 -N 1 -d 1 -cc cpu gdb Solver run.xml
> 
> but so only one gdb instance is invoked in the terminal window, the
> other is in a parallel universe or something... Still any chance to
> get the second window somehow?
> 
> Thanks
> Dominik
> 
> On Mon, Dec 12, 2011 at 1:52 PM, Aron Ahmadia <aron.ahmadia at kaust.edu.sa> wrote:
> > Sorry, to expand my answer, "what Matt said".  You don't have the advantage
> > of using the functionality of -start_in_debugger if you cannot make X11
> > connections from the compute nodes, so you will need to rely on whatever
> > debugging facilities your systems team has set up, and break on PetscError
> > if you want to catch PETSc errors percolating up the stack.
> >
> > A
> >
> >
> > On Mon, Dec 12, 2011 at 3:48 PM, Aron Ahmadia <aron.ahmadia at kaust.edu.sa>
> > wrote:
> >>
> >> Not on a BG/P you can't.
> >>
> >> A
> >>
> >>
> >> On Mon, Dec 12, 2011 at 3:46 PM, Matthew Knepley <knepley at gmail.com>
> >> wrote:
> >>>
> >>> On Mon, Dec 12, 2011 at 2:48 AM, Dominik Szczerba <dominik at itis.ethz.ch>
> >>> wrote:
> >>>>
> >>>> Hi,
> >>>> I am debugging my code on a system that does not allow any X11
> >>>> connections, therefore the following does not work:
> >>>>
> >>>> mpiexec -n 2 solver run.xml -start_in_debugger -display :0.0
> >>>>
> >>>> Are there alternative ways of using a debugger circumventing X11
> >>>> connections?
> >>>
> >>>
> >>> No. You can usually set the DISPLAY correctly for the backend machine.
> >>> Consult the admin.
> >>>
> >>>    Matt
> >>>
> >>>>
> >>>> Thanks
> >>>> Dominik
> >>>
> >>>
> >>>
> >>>
> >>> --
> >>> What most experimenters take for granted before they begin their
> >>> experiments is infinitely more interesting than any results to which their
> >>> experiments lead.
> >>> -- Norbert Wiener
> >>
> >>
> >
>