Chrome reinitiates AJAX POST request after a 10 second timeout

Question

I'm building a React javascript application with a Nodejs and Express backend.

Versions: React: ^16.0.0 Node: v8.0.0 Express: ^4.14.0 Chrome: Version 63.0.3239.84 (Official Build) (64-bit)

The POST request is a file upload, with the file attached to a FormData() object. The server doesn't respond until the images are uploaded successfully to AWS S3. For large images, which take longer than approximately 10000ms to upload, Chrome re-initiates the POST request. This causes the images to upload twice.

I've tested by setting a setTimeout of 10000ms before sending the response back, and tested with a very small image. The image uploads just fine without the timeout. But with the timeout it will upload twice.

This behaviour doesn't happen in Firefox.

This thread seems to report the same issue I'm having: link .

Supposedly the server is sending back a 408 request, but I can't confirm that. How can I prevent Chrome from re-initiating the POST request on large uploads?

Answer 1

Found the answer here :

app.post('/long_processing_thing', function(req, res){
  req.setTimeout(0) // no timeout
  do_something_long(req, res)
})

You can easily change the timeout of a request in express using req.setTimeout .