Mongrel server

Is there any way to restart running mongrel server for each separated virtual host ? Ruby applications behave stragne (or in their own rules) so when I modifie something in code I need to see it "online" in browser and it sometime demands restart of mongrel server. So is there any way to restart it?

And second question. Can I somehow monitor if mongrel servers are running and responding (I hope it can be done through monitoring services) and if it is not running rerun mongrel server?

Thanks for any idea.

Thanks.