i was trying to install launchpad by using rocketfuel-setup, it is always installing the development version. how do i install launchpad stable version ? what is the recommended setup(no of nodes,caching server etc) ?
For "stable", you would simply take the stable branch rather than the development branch (lp:launchpad/stable rather than lp:launchpad/devel).
Launchpad works fine on a single machine, there is no need for multiple nodes if you want a basic setup. You'll probably want quite a bit of memory though.