urlfetch DeadlineExceededError

Question

I had a create a REST API using bottle framework, which receives calls from GAE. Once this REST API is invoked, it did some calculations and sent outputs as a zip file to AMAZON S3 server and return the link to GAE. Everything works fine expect the timeout issue. I tried to adjust the deadline of urlfetch to 60 seconds, which did not solve the problem. I appreciate any suggestions.

GAE side:

response = urlfetch.fetch(url=url, payload=data, method=urlfetch.POST, headers=http_headers, deadline=60) 

Broser error info.:

Traceback (most recent call last):
  File "C:\Program Files (x86)\Google\google_appengine\lib\webapp2-2.5.2\webapp2.py", line 1535, in __call__
    rv = self.handle_exception(request, response, e)
  File "C:\Program Files (x86)\Google\google_appengine\lib\webapp2-2.5.2\webapp2.py", line 1529, in __call__
    rv = self.router.dispatch(request, response)
  File "C:\Program Files (x86)\Google\google_appengine\lib\webapp2-2.5.2\webapp2.py", line 1278, in default_dispatcher
    return route.handler_adapter(request, response)
  File "C:\Program Files (x86)\Google\google_appengine\lib\webapp2-2.5.2\webapp2.py", line 1102, in __call__
    return handler.dispatch()
  File "C:\Program Files (x86)\Google\google_appengine\lib\webapp2-2.5.2\webapp2.py", line 572, in dispatch
    return self.handle_exception(e, self.app.debug)
  File "C:\Program Files (x86)\Google\google_appengine\lib\webapp2-2.5.2\webapp2.py", line 570, in dispatch
    return method(*args, **kwargs)
  File "D:\Dropbox\ubertool_src\przm5/przm5_output.py", line 22, in post
    przm5_obj = przm5_rest_model.przm5(args)
  File "D:\Dropbox\ubertool_src\przm5\przm5_rest_model.py", line 351, in __init__
    self.convertSoil1, self.convert1to3, self.convert2to3)
  File "D:\Dropbox\ubertool_src\przm5\przm5_rest_model.py", line 135, in get_jid
    response = urlfetch.fetch(url=url, payload=data, method=urlfetch.POST, headers=http_headers)
  File "C:\Program Files (x86)\Google\google_appengine\google\appengine\api\urlfetch.py", line 270, in fetch
    return rpc.get_result()
  File "C:\Program Files (x86)\Google\google_appengine\google\appengine\api\apiproxy_stub_map.py", line 612, in get_result
    return self.__get_result_hook(self)
  File "C:\Program Files (x86)\Google\google_appengine\google\appengine\api\urlfetch.py", line 410, in _get_fetch_result
    'Deadline exceeded while waiting for HTTP response from URL: ' + url)
DeadlineExceededError: Deadline exceeded while waiting for HTTP response from URL: http://localhost:7777/my_model

REST server:

@route('/my_model', method='POST') 
@auth_basic(check)
def my_model():
    #run the model
    run_my model()

    #zip output files
    zout=zipfile.ZipFile("test.zip","w")
    for name in os.listdir(src1):
        zout.write(name)
    zout.close()

    ##upload file to S3
    conn = S3Connection(key, secretkey)
    bucket = Bucket(conn, 'przm5')
    k=Key(bucket)
    name1='PRZM5_'+name_temp+'.zip'
    k.key=name1

    ###All the above steps are fine####
    k.set_contents_from_filename('test.zip')
    link='https://s3.amazonaws.com/'+my_file_path
    return {'ff': ff}

run(host='localhost', port=7777, debug=True)

Errors from the REST server:

127.0.0.1 - - [07/Jan/2014 16:16:36] "POST /my_model HTTP/1.1" 200 1663
Traceback (most recent call last):
  File "C:\Python27\Lib\wsgiref\handlers.py", line 86, in run
    self.finish_response()
  File "C:\Python27\Lib\wsgiref\handlers.py", line 128, in finish_response
    self.write(data)
  File "C:\Python27\Lib\wsgiref\handlers.py", line 212, in write
    self.send_headers()
  File "C:\Python27\Lib\wsgiref\handlers.py", line 270, in send_headers
    self.send_preamble()
  File "C:\Python27\Lib\wsgiref\handlers.py", line 194, in send_preamble
    'Date: %s\r\n' % format_date_time(time.time())
  File "C:\Python27\Lib\socket.py", line 324, in write
    self.flush()
  File "C:\Python27\Lib\socket.py", line 303, in flush
    self._sock.sendall(view[write_offset:write_offset+buffer_size])
error: [Errno 10053] An established connection was aborted by the software in your host machine
127.0.0.1 - - [07/Jan/2014 16:16:36] "POST /my_model HTTP/1.1" 500 59
----------------------------------------
Exception happened during processing of request from ('127.0.0.1', 50953)
Traceback (most recent call last):
  File "C:\Python27\Lib\SocketServer.py", line 295, in _handle_request_noblock
    self.process_request(request, client_address)
  File "C:\Python27\Lib\SocketServer.py", line 321, in process_request
    self.finish_request(request, client_address)
  File "C:\Python27\Lib\SocketServer.py", line 334, in finish_request
    self.RequestHandlerClass(request, client_address, self)
  File "C:\Python27\Lib\SocketServer.py", line 651, in __init__
    self.finish()
  File "C:\Python27\Lib\SocketServer.py", line 710, in finish
    self.wfile.close()
  File "C:\Python27\Lib\socket.py", line 279, in close
    self.flush()
  File "C:\Python27\Lib\socket.py", line 303, in flush
    self._sock.sendall(view[write_offset:write_offset+buffer_size])
error: [Errno 10053] An established connection was aborted by the software in your host machine

Answer 1

The deadline is a maximum value, once reached it'll fail. And it's failing with

Deadline exceeded while waiting for HTTP response

So you should try to catch that exception and try again.

If the entire operation can't be done in under 60 seconds then there is nothing else to be done, it's a hard limit in GAE that HTTP requests can't exceed 60 seconds.