Using cssh is easy. First, install it:
make install clean
This assumes you have x11/xterm installed (I did).
Then run it:
cssh mysql41 mysql50 mysql51 mysql54
The following screen shot shows the above session opened and running with
The small window in the top left is cssh. This is where you type commands
that will be echoed to each window. If you need to do something with just
one window, click on it and type away. When you want to control all
the session again, click on the cssh window.
This is something I will be using often.