Thank you.

BTW: having googled it for different expressions I've found that it is a well known issue and that it has nothing to do with nginx or the Rails app itself. Unicorn in and of itself can neither be blamed (albeit IMHO there should be some official documentation on this issue, esp. since nginx is the preferred/"official" web server for unicorn). It looks like a socket backlog setting issue to be handled at OS level but I'm still unsure if that's a resolution or not.