We did this, but all it did was buy us a bit of extra time before we ran into the same problem again - a very small percentage (<0.1%) of requests creating a queue that destroyed performance for the rest of them. Also, FWIW, Heroku does not officially support Unicorn, and you have to make sure that you don't run out of memory on your dynos (we tanked our app the first time we tried Unicorn with 4 processes).