not really a suitable task for a full on tool.... either use a ssh script to run the commands, or maybe schedule a cron job to attempt to install any rpm's located in a given directory. it's a doddle, and not the sort of thing you should be baulking at if you're already successfully running a linux cluster.
Code:
for host in alpha beta gamma delta
do
ssh $host 'rpm -Uvh /mount/network/something.rpm'
done
there's your "tool"
Looking for a Batch Software Upgrade tool
