The -sessionsuffix as a command line option to LAM tools is not
currently universally supported. lamhalt is one of the applications
that does not currently support the -sessionsuffix argument. The
only way to use lamhalt is to use the environment variable
LAM_MPI_SESSION_SUFFIX. The advantage to LAM_MPI_SESSION_SUFFIX is
that all LAM/MPI commands understand and obey it.
Hope this helps,
Brian
On Jul 18, 2007, at 10:57 AM, Vechinski, Douglas A. wrote:
>
> I understand the first paragraph about the different lam universes.
> If LAM_MPI_SESSION_SUFFIX is set, then I can follow how lamhalt can
> use
> that to decide which lam daemon to kill. However, suppose one used
> the
> -sessionsuffix argument to lamboot instead of the
> LAM_MPI_SESSION_SUFFIX. Since the environment variable is not set
> when
> lamhalt is issued, how then does lamhalt decide which is the correct
> sessionsuffix to chose to halt the particular lam universe.
>
>
> -----Original Message-----
> From: Brian Barrett [mailto:brbarret_at_[hidden]]
> Sent: Tuesday, July 17, 2007 9:59 PM
> To: General LAM/MPI mailing list
> Subject: Re: LAM: Does lamhalt use LAM_MPI_SESSION_SUFFIX
>
>
> A given LAM daemon only knows the contact information for other
> daemons in it's "universe", which is the group of daemons started
> with the 'lamboot' command. Other daemons started with other calls
> to 'lamboot' are in a different universe and are not in communication
> with the first universe.
>
> Lamhalt just sends a message to its local LAM daemon to get all the
> daemons in the universe, then sends all of them a die message. The
> universe to get the information from is determined by the session
> directory (so usually the SESSION_SUFFIX).
>
> So as long as the same value for LAM_MPI_SESSION_SUFFIX that was
> there when lamboot was run is there when lamhalt is run, only those
> daemons started by the given lamboot will be killed. All others will
> continue on without disruption.
>
>
> Brian
--
Brian Barrett
LAM/MPI Developer
Make today a LAM/MPI day!
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