I have password-less ssh and rsh (I've tried both; same
"Connection refused" error). My home directory is NFS mounted to all
slave machines. I successfully ran parallel python with Modeller9v7 in
the past with this setup but now since updating to Mod9v8 I'm not able
to run the same scripts. It's been a while since I've used Modeller so
I'm not sure if the problem is due to updating Modeller or changes that
might have occurred in the computer configurations. Again ssh and rsh
work seamlessly between all nodes without passwords.
It's not a change between 9v7 and 9v8 - in fact, the parallel framework
was not modified at all between these two releases.
If the connection is refused, I can think of only two possibilities:
1. You have a firewall preventing such connections (in this case no
Modeller jobs will run).
2. The master process died (thus closing the listening socket) before
the slave was able to start up - perhaps due to a syntax error in your
script. In this case you should be able to see it from the master output
(not the slave output).