有什么方法可以延长请求超时限制？

Question

I am getting

[2] [CRITICAL] WORKER TIMEOUT at=error code=H12 desc="Request timeout" method=POST dyno=web.1 connect=1ms service=30000ms

I am starting a flask web app on heroku with

web: gunicorn server:app --timeout 60 --worker-class gevent --log-file=-

The --timeout flag doesn't seem to matter whether I use sync or gevent workers. Any ideas how I can extend the request timeout limit?

Of course, I'd probably need to look into async handling of such long processes.

Answer 1

As answered on an official Heroku discussion (link is dead now), we can't set the timeout upper than 30 seconds:

Heroku kills all requests that take longer than 30s. There is no way to change that behavior.

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You need to redesign how you send your request by splitting your call into multiple, smaller chunks. Javascript is the way to go.

Answer 2

This is not specific to Heroku but it is a bad idea in general to increase the timeout; the idea being you should return a response as immediately as possible - and for anything that could take more than a few seconds you should accept the request, queue it for background processing and return a response so your client isn't blocked.

For Heroku this means you have to spool up a worker process. This is different than a web dyno which you already have in that it is designed to run in the background and does not have such timeout restrictions.

For a great over on this common pattern, there is an excellent writeup at the devcenter on this that details the entire process.

Specifically for Python on Heroku, this is implemented using redis queue .