I am not really sure how Rails behaves these days behind an evented web server, and I also don't know if nginx+passenger offer such a setup; but I was running a

I am not really sure how Rails behaves these days behind an evented web server, and I also don't know if nginx+passenger offer such a setup; but I was running a similar application with Sinatra+Thin, which handled hundreds, if not thousands connections easily. Especially the number of 4 successful connections and then none make me suspect that something in the Rails setup was broken and/or that Rails still does not support long running requests.