Some time ago I dealt with this exact bug for an e-commerce site with millions of requests per day, and it was also Rails + Unicorn.
ANY time ruby 1.8 raised a timeout, it was silently swallowed, and Unicorn returned the adjacent request session_id. We had to constantly defend against any code that might hit the native timeout.
ANY time ruby 1.8 raised a timeout, it was silently swallowed, and Unicorn returned the adjacent request session_id. We had to constantly defend against any code that might hit the native timeout.