[Fixed]-How to set timeout for urlfetch in Google App Engine?

24👍

You can set it using the deadline argument of the fetch function. From the docs:

The deadline can be up to a maximum of 60 seconds for request handlers and 10 minutes for tasks queue and cron job handlers. If deadline is None, the deadline is set to 5 seconds.


Edit: looks like this has changed now. From here:

You can set a deadline for a request, the most amount of time the service will wait for a response. By default, the deadline for a fetch is 5 seconds. You can adjust the default deadline for requests using the urlfetch.set_default_fetch_deadline() function.

And this page lists the default timeout values:

Currently, there are several errors named DeadlineExceededError for the Python runtime:

  • google.appengine.runtime.DeadlineExceededError: raised if the overall request times out, typically after 60 seconds, or 10 minutes for task queue requests.
  • google.appengine.runtime.apiproxy_errors.DeadlineExceededError: raised if an RPC exceeded its deadline. This is typically 5 seconds, but it is settable for some APIs using the ‘deadline’ option.
  • google.appengine.api.urlfetch_errors.DeadlineExceededError: raised if the URLFetch times out.

27👍

Seeing as this is a Python question, I thought I’d provide a Python answer for anyone who comes across this problem.

Just import urlfetch and then define a deadline before doing anything else in your code:

from google.appengine.api import urlfetch

urlfetch.set_default_fetch_deadline(60)

7👍

For Go, you might want to try below code.

// createClient is urlfetch.Client with Deadline
func createClient(context appengine.Context, t time.Duration) *http.Client {
    return &http.Client{
        Transport: &urlfetch.Transport{
            Context:  context,
            Deadline: t,
        },
    }
}

Here is how to use it.

// urlfetch
client := createClient(c, time.Second*60)

-2👍

It seems short but you have to know that the timeout of a request on GAE is around 30 seconds. As you probably need to do some operations on the response of your urlfetch, there’s no need to have a timeout more than 10 seconds I think.

👤Jeremy

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