In reply to Timo.

Timo - After trying this setup out for a while, Upstart (and probably init) is a pretty good place to spawn from. Processes are respawned immediately after they've died. It's also very easy to setup with Upstart - the config is pretty simple. Also, there's little chance of either Upstart or init dying. Probably the biggest issue will be processes which are hung, rather than terminated.