Rails Nginx Unicorn webapp that was running fine is now saying 502 bad gateway

My old capistrano recipes are not working and I am not sure how to restart the unicorn workers from within the server to begin troubleshooting. I'd rather hire someone here to get this working. The app was running for about 8 months with no problems. Suddenly, today, the app started throwing 502 Bad Gateway errors. I am running a Spree Commerce store (version 1.3.2) (if it matters) and i will be able to give you access to the previous capistrano deploy recipes that worked previously (in addition to access to the server, of course).