[gentoo-user] executing commands on lots of servers at once

[James]

I have a cluster of Gentoo boxes I'd like to update all at once, along
with emerging specific packages to the servers simultaneously.

Does anyone have any experience(s) with a good utility for doing this?
I've seen a few scripts online for accomplishing this but I'm not sure
how these scripts would handle the large amount of output that emerge
generates from all the servers simultaneously.

Thoughts / ideas appreciated.

-j