heroku Heroku Error Codes H12 - Request timeout


An HTTP request took longer than 30 seconds to complete. In the example below, a Rails app takes 37 seconds to render the page; the HTTP router returns a 503 prior to Rails completing its request cycle, but the Rails process continues and the completion message shows after the router message.

2010-10-06T21:51:07-07:00 app[web.2]: Processing PostController#list (for at 2010-10-06 21:51:07) [GET]
2010-10-06T21:51:08-07:00 app[web.2]: Rendering template within layouts/application
2010-10-06T21:51:19-07:00 app[web.2]: Rendering post/list
2010-10-06T21:51:37-07:00 heroku[router]: at=error code=H12 desc="Request timeout" method=GET path="/" host=myapp.herokuapp.com fwd= dyno=web.1 connect=6ms service=30001ms status=503 bytes=0
2010-10-06T21:51:42-07:00 app[web.2]: Completed in 37000ms (View: 27, DB: 21) | 200 OK [http://myapp.heroku.com/]

This 30-second limit is measured by the router, and includes all time spent in the dyno, including the kernel’s incoming connection queue and the app itself.