[chef] Can you recommend a command-and-control tool?

[Mike Williams < >]

I'm helping a client rebuild their configuration management and software 
deployment tooling, and we have Chef successfully doing both ... but only on 
a per-node basis.  Now I'm looking to add a layer above Chef, to orchestrate 
software/platform updates across a data-center, in a controlled fashion.

Any recommendations?  Has anyone successfully used something like mcollective 
or nanite, with Chef,  to do this kind of orchestration?  Do recipes exist to 
install these?  (The opscode repo contains a nanite cookbook, but it appears 
to be deprecated).  Or, do most people find "knife exec" sufficient?

-- 
cheers, 
Mike Williams