Extend Heroku 30 seconds limit

Question

I have a Sinatra app that looks something like this:

get '/generate'
  generate_result(params) # method that takes several minutes to complete
end

Unfortunately, method 'generate_result' takes several minutes to run. But Heroku's limitation is 30 seconds per request. I'm using a free Heroku account, so I'm looking for a solution that doesn't require buying a worker dyno.

I tried 'rack-timeout' gem, but the problem still appears on Heroku.

Split it in multiple smaller task and request each with ajax or something like that? — Sir l33tname, May 25 '15 at 18:32
So I guess generate a part with js is also not an option, whats about pregeneration on your workstation? — Sir l33tname, May 25 '15 at 19:22
Well I guess then you are out of options since a heroku web request is limited to 30 seconds. — Sir l33tname, May 26 '15 at 12:30

score 2 · Answer 1 · answered May 26 '15 at 14:02

In order to support web sockets and long polling, Heroku provides a way around the timeout. Upon the initial request, you have 30 seconds to respond to the client with at least one byte, after which each subsequent byte will keep the connection open for at least 55 seconds.

https://devcenter.heroku.com/articles/request-timeout#long-polling-and-streaming-responses

As a hack, you can thus repeatedly send "heartbeat" messages over the connection in order to keep it alive. The remaining question is whether it's worth it – usually you'd be better off by doing background processing.

Extend Heroku 30 seconds limit

1 Answers1