I found during my test that in case the first execution crashes, a mpd.py process on remote host does not exit automatically.
Here're the steps, assume you have two host host1 and host2
start a mpd ring on the two hosts under normal user:
mpdboot -n 2 -f $hfile
in which hfile contains two hosts host1 and host2
on host1, kill -9 the mpd process and all intel mpi process in one shot
on host2 (remote host), you see a left over mpd.py process
Is there a way to make the mpd ring exit by itself in a clean way?