= Description =

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This is not strictly a magpar bug but a problem with MPICH2 (version 1.2 and 1.2.1), which affects parallel runs on multiple machines.

== Steps to reproduce ==
## Describe the steps needed to reproduce the bug. If we can't reproduce it, we  probably can't fix it.
 1. Prepare parallel magpar run on Linux cluster using MPICH2 1.2 or 1.2.1
 2. Start mpd ring spanning several machines using "mpdboot" command
 3. mpdboot command does not return (hangs)

== Example and Details ==

 * MPICH2 trouble ticket [[https://trac.mcs.anl.gov/projects/mpich2/ticket/963|963]]
 * related MPICH2 trouble ticket [[https://trac.mcs.anl.gov/projects/mpich2/ticket/974|974]]

== Workaround ==
## How to deal with the bug until it is fixed

 * Use MPICH2 version [[http://www.mcs.anl.gov/research/projects/mpich2/downloads/tarballs/1.2.1p1/mpich2-1.2.1p1.tar.gz|1.2.1p1]] or later
 * or follow the instructions at the bottom of [[https://trac.mcs.anl.gov/projects/mpich2/ticket/963|this page]] in the MPICH2 trac system.
 * or edit/patch mpd.py directly according to [[https://trac.mcs.anl.gov/projects/mpich2/changeset/5923|this changeset]]
 * or download [[https://trac.mcs.anl.gov/projects/mpich2/export/5923/mpich2/trunk/src/pm/mpd/mpd.py|this version of mpd.py]] and use it instead of the mpd.py installed by MPICH2 >=1.2.
 * or use older MPICH2 version [[http://www.mcs.anl.gov/research/projects/mpich2/downloads/tarballs/1.0.8p1/mpich2-1.0.8p1.tar.gz|1.0.8p1]]

= Plan =
## This part is for magpar developers:

 * Priority: Medium
 * Assigned to: MPICH2 developers
 * Status: fixed in MPICH2 version [[http://www.mcs.anl.gov/research/projects/mpich2/downloads/tarballs/1.2.1p1/mpich2-1.2.1p1.tar.gz|1.2.1p1]]: revision [[https://trac.mcs.anl.gov/projects/mpich2/changeset/5923|5923]]

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CategoryMagparBugFixed