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Subject: Re: [OMPI devel] Multiworld MCA parameter values broken
From: Tim Prins (tprins_at_[hidden])
Date: 2007-11-08 14:25:01

The alias option you presented does not work. I think we do some weird
things to find the absolute path for ssh, instead of just issuing the

I would spend some time fixing this, but I don't want to do it wrong. We
could quote all the param values, and change the parser to remove the
quotes, but this is assuming that a mca param does not contain quotes.

So I guess there are 2 questions that need to be answered before a fix
is made:

1. What exactly can a string mca param contain? Can it have quotes or
spaces or?

2. Which mca parameters should be forwarded? Should it be just the ones
from the command line? From the environment? From config files?


Ralph Castain wrote:
> What changed is that we never passed mca params to the orted before - they
> always went to the app, but it's the orted that has the issue. There is a
> bug ticket thread on this subject - I forget the number immediately.
> Basically, the problem was that we cannot generally pass the local
> environment to the orteds when we launch them. However, people needed
> various mca params to get to the orteds to control their behavior. The only
> way to resolve that problem was to pass the params via the command line,
> which is what was done.
> Except for a very few cases, all of our mca params are single values that do
> not include spaces, so this is not a problem that is causing widespread
> issues. As I said, I already had to deal with one special case that didn't
> involve spaces, but did have special characters that required quoting, which
> identified the larger problem of dealing with quoted strings.
> I have no objection to a more general fix. Like I said in my note, though,
> the general fix will take a larger effort. If someone is willing to do so,
> that is fine with me - I was only offering solutions that would fill the
> interim time as I haven't heard anyone step up to say they would fix it
> anytime soon.
> Please feel free to jump in and volunteer! ;-) I'm willing to put the quotes
> around things if you will fix the mca cmd line parser to cleanly remove them
> on the other end.
> Ralph
> On 11/7/07 5:50 PM, "Tim Prins" <tprins_at_[hidden]> wrote:
>> I'm curious what changed to make this a problem. How were we passing mca param
>> from the base to the app before, and why did it change?
>> I think that options 1 & 2 below are no good, since we, in general, allow
>> string mca params to have spaces (as far as I understand it). So a more
>> general approach is needed.
>> Tim
>> On Wednesday 07 November 2007 10:40:45 am Ralph H Castain wrote:
>>> Sorry for delay - wasn't ignoring the issue.
>>> There are several fixes to this problem - ranging in order from least to
>>> most work:
>>> 1. just alias "ssh" to be "ssh -Y" and run without setting the mca param.
>>> It won't affect anything on the backend because the daemon/procs don't use
>>> ssh.
>>> 2. include "pls_rsh_agent" in the array of mca params not to be passed to
>>> the orted in orte/mca/pls/base/pls_base_general_support_fns.c, the
>>> orte_pls_base_orted_append_basic_args function. This would fix the specific
>>> problem cited here, but I admit that listing every such param by name would
>>> get tedious.
>>> 3. we could easily detect that a "problem" character was in the mca param
>>> value when we add it to the orted's argv, and then put "" around it. The
>>> problem, however, is that the mca param parser on the far end doesn't
>>> remove those "" from the resulting string. At least, I spent over a day
>>> fighting with a problem only to discover that was happening. Could be an
>>> error in the way I was doing things, or could be a real characteristic of
>>> the parser. Anyway, we would have to ensure that the parser removes any
>>> surrounding "" before passing along the param value or this won't work.
>>> Ralph
>>> On 11/5/07 12:10 PM, "Tim Prins" <tprins_at_[hidden]> wrote:
>>>> Hi,
>>>> Commit 16364 broke things when using multiword mca param values. For
>>>> instance:
>>>> mpirun --debug-daemons -mca orte_debug 1 -mca pls rsh -mca pls_rsh_agent
>>>> "ssh -Y" xterm
>>>> Will crash and burn, because the value "ssh -Y" is being stored into the
>>>> argv orted_cmd_line in orterun.c:1506. This is then added to the launch
>>>> command for the orted:
>>>> /usr/bin/ssh -Y odin004 PATH=/san/homedirs/tprins/usr/rsl/bin:$PATH ;
>>>> export PATH ;
>>>> LD_LIBRARY_PATH=/san/homedirs/tprins/usr/rsl/lib:$LD_LIBRARY_PATH ;
>>>> export LD_LIBRARY_PATH ; /san/homedirs/tprins/usr/rsl/bin/orted --debug
>>>> --debug-daemons --name 0.1 --num_procs 2 --vpid_start 0 --nodename
>>>> odin004 --universe tprins_at_[hidden]:default-universe-27872
>>>> --nsreplica
>>>> "0.0;tcp://;tcp6://2001:18e8:2:240:2e0:81ff:fe2d:21a0
>>>> :4090 8"
>>>> --gprreplica
>>>> "0.0;tcp://;tcp6://2001:18e8:2:240:2e0:81ff:fe2d:21a0
>>>> :4090 8"
>>>> -mca orte_debug 1 -mca pls_rsh_agent ssh -Y -mca
>>>> mca_base_param_file_path
>>>> /u/tprins/usr/rsl/share/openmpi/amca-param-sets:/san/homedirs/tprins/rsl/
>>>> examp les
>>>> -mca mca_base_param_file_path_force /san/homedirs/tprins/rsl/examples
>>>> Notice that in this command we now have "-mca pls_rsh_agent ssh -Y". So
>>>> the quotes have been lost, as we die a horrible death.
>>>> So we need to add the quotes back in somehow, or pass these options
>>>> differently. I'm not sure what the best way to fix this.
>>>> Thanks,
>>>> Tim