App Engine后端实例超时（Python）

Question

目前我正在为我的网站使用动态后端实例，但我仍然遇到超时问题。我网站的背景是：

1. GAE用作处理用户请求的前端。
2. 请求将被发送到EC2休息服务器（使用bottle）进行处理。

以下是GAE日志中的错误信息。似乎GAE在60秒后停止了我的后端线程。我很感激任何建议。

ERROR    2014-02-20 14:42:18,365 module.py:660] Request to '/_ah/background' failed
Traceback (most recent call last):
  File "C:\Program Files (x86)\Google\google_appengine\google\appengine\tools\devappserver2\module.py", line 637, in _handle_request
    environ, wrapped_start_response)
  File "C:\Program Files (x86)\Google\google_appengine\google\appengine\tools\devappserver2\request_rewriter.py", line 311, in _rewriter_middleware
    response_body = iter(application(environ, wrapped_start_response))
  File "C:\Program Files (x86)\Google\google_appengine\google\appengine\tools\devappserver2\module.py", line 1524, in _handle_script_request
    request_type)
  File "C:\Program Files (x86)\Google\google_appengine\google\appengine\tools\devappserver2\module.py", line 1476, in _handle_instance_request
    request_id, request_type)
  File "C:\Program Files (x86)\Google\google_appengine\google\appengine\tools\devappserver2\instance.py", line 382, in handle
    request_type))
  File "C:\Program Files (x86)\Google\google_appengine\google\appengine\tools\devappserver2\http_runtime.py", line 244, in handle
    response = connection.getresponse()
  File "C:\Python27\Lib\httplib.py", line 1045, in getresponse
    response.begin()
  File "C:\Python27\Lib\httplib.py", line 409, in begin
    version, status, reason = self._read_status()
  File "C:\Python27\Lib\httplib.py", line 365, in _read_status
    line = self.fp.readline(_MAXLINE + 1)
  File "C:\Python27\Lib\socket.py", line 476, in readline
    data = self._sock.recv(self._rbufsize)
error: [Errno 10054] An existing connection was forcibly closed by the remote host

的app.yaml

- url: /backend.html
  script: przm_batchmodel.py

backends.yaml

backends:
- name: mybackend
  class: B1
  instances: 1
  options: dynamic

Output.py

def loop_html(thefile):
    ####do some thing###
    response = urlfetch.fetch(url=my_REST_server_URL, payload=data, method=urlfetch.POST, headers=http_headers, deadline=6000)   
    return response

class przmBatchOutputPage(webapp.RequestHandler):
    def post(self):
        form = cgi.FieldStorage()
        thefile = form['file-0']
        html = background_thread.BackgroundThread(target=loop_html, args=[thefile, generate_batch_jid()])
        html.start()
        self.response.out.write(html)

app = webapp.WSGIApplication([('/.*', przmBatchOutputPage)], debug=True)