why I use AsyncHTTPClient timeout? - timeout

Question

#tornado.web.authenticated
#tornado.web.asynchronous
#tornado.gen.coroutine
def post(self):
try:
files_body = self.request.files['file']
except:
error_msg = u"failed to upload file"
error_msg = self.handle_error(error_msg)
self.finish(dict(is_succ=False, error_msg=error_msg))
return
file_ = files_body[0]
filename = file_['filename']
# asynchronous request， obtain OCR info
files = [('image', filename, file_['body'])]
fields = (('api_key', config.OCR_API_KEY), ('api_secret', config.OCR_API_SECRET))
content_type, body = encode_multipart_formdata(fields, files)
headers = {"Content-Type": content_type, 'content-length': str(len(body))}
request = tornado.httpclient.HTTPRequest(config.OCR_HOST, method="POST", headers=headers, body=body,
validate_cert=False, request_timeout = 30)
try:
response = yield tornado.httpclient.AsyncHTTPClient().fetch(request)
except Exception, e:
logging.error(u'orc timeout {}'.format(e))
error_msg = u"OCR timeout"
error_msg = self.handle_error(error_msg)
self.finish(dict(is_succ=False, error_msg=error_msg))
return
if not response.error and response.body:
data = json.loads(response.body)
self.extra_info(data)
result = dict(is_succ=True, error_msg=u"", data=data)
else:
result = dict(is_succ=False, error_msg=u"request timeout", data={})
self.finish(result)
as the code shown, I want to write an api to handle id-card picture upload, and post a request to third part interface for getting the information of id-card.
This api can run well on my PC，however it timeouts on Testing Server. I cannot figure out where the problem is.