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當我嘗試按照pyzmq official documentation中所述組合Tornado和pyzmq ioloops時，遇到了一個惱人的問題（雖然不是關鍵）。結合龍捲風和zmq ioloops：通過同位異常重置連接
我有接受來自客戶端（C）REST API請求，並代理他們運行的進程龍捲風（T）服務器雖然ZMQ運輸到另一個進程（Z），做實際工作。
C <-> T <-> Z
如果C關閉連接之前Ž答覆T，Z（龍捲風）輸出一束長異常跡線（見在底部）。想象一下下面的例子：
import tornado.ioloop
from tornado.web import Application, RequestHandler, asynchronous
from zmq.eventloop import ioloop
import time
def time_consuming_task():
time.sleep(5)
class TestHandler(RequestHandler):
def get(self, arg):
print "Test arg", arg
time_consuming_task()
print "Ok, time to reply"
self.write("Reply")
if __name__ == "__main__":
app = tornado.web.Application(
[
(r"/test/([0-9]+)", TestHandler)
])
ioloop.install()
app.listen(8080)
tornado.ioloop.IOLoop.instance().start()
這個例子實際上並沒有跟任何ZMQ同行，它只是重視pyzmq ioloop龍捲風的ioloop。雖然，這足以說明問題。
從控制檯一個運行服務器：
% python example.py
從控制檯兩個運行客戶端和（在5秒即）服務器回覆之前中斷它：
% curl -is http://localhost:8080/test/1
^C
服務器的輸出是：
Test arg 1
Ok, time to reply
WARNING:root:Read error on 24: [Errno 54] Connection reset by peer
ERROR:root:Uncaught exception GET /test/1 (::1)
HTTPRequest(protocol='http', host='localhost:8080', method='GET', uri='/test/1', version='HTTP/1.1', remote_ip='::1', body='', headers={'Host': 'localhost:8080', 'Accept': '*/*', 'User-Agent': 'curl/7.21.4 (universal-apple-darwin11.0) libcurl/7.21.4 OpenSSL/0.9.8r zlib/1.2.5'})
Traceback (most recent call last):
File "/Library/Python/2.7/site-packages/tornado/web.py", line 1023, in _execute
self.finish()
File "/Library/Python/2.7/site-packages/tornado/web.py", line 701, in finish
self.request.finish()
File "/Library/Python/2.7/site-packages/tornado/httpserver.py", line 433, in finish
self.connection.finish()
File "/Library/Python/2.7/site-packages/tornado/httpserver.py", line 187, in finish
self._finish_request()
File "/Library/Python/2.7/site-packages/tornado/httpserver.py", line 223, in _finish_request
self.stream.read_until(b("\r\n\r\n"), self._header_callback)
File "/Library/Python/2.7/site-packages/tornado/iostream.py", line 153, in read_until
self._try_inline_read()
File "/Library/Python/2.7/site-packages/tornado/iostream.py", line 386, in _try_inline_read
if self._read_to_buffer() == 0:
File "/Library/Python/2.7/site-packages/tornado/iostream.py", line 421, in _read_to_buffer
chunk = self._read_from_socket()
File "/Library/Python/2.7/site-packages/tornado/iostream.py", line 402, in _read_from_socket
chunk = self.socket.recv(self.read_chunk_size)
error: [Errno 54] Connection reset by peer
ERROR:root:Cannot send error response after headers written
ERROR:root:Uncaught exception, closing connection.
Traceback (most recent call last):
File "/Library/Python/2.7/site-packages/tornado/iostream.py", line 304, in wrapper
callback(*args)
File "/Library/Python/2.7/site-packages/tornado/httpserver.py", line 262, in _on_headers
self.request_callback(self._request)
File "/Library/Python/2.7/site-packages/tornado/web.py", line 1412, in __call__
handler._execute(transforms, *args, **kwargs)
File "/Library/Python/2.7/site-packages/tornado/web.py", line 1025, in _execute
self._handle_request_exception(e)
File "/Library/Python/2.7/site-packages/tornado/web.py", line 1065, in _handle_request_exception
self.send_error(500, exc_info=sys.exc_info())
File "/Library/Python/2.7/site-packages/tornado/web.py", line 720, in send_error
self.finish()
File "/Library/Python/2.7/site-packages/tornado/web.py", line 700, in finish
self.flush(include_footers=True)
File "/Library/Python/2.7/site-packages/tornado/web.py", line 660, in flush
self.request.write(headers + chunk, callback=callback)
File "/Library/Python/2.7/site-packages/tornado/httpserver.py", line 429, in write
self.connection.write(chunk, callback=callback)
File "/Library/Python/2.7/site-packages/tornado/httpserver.py", line 177, in write
assert self._request, "Request closed"
AssertionError: Request closed
ERROR:root:Exception in callback
Traceback (most recent call last):
File "/Library/Python/2.7/site-packages/pyzmq-2.2.0-py2.7-macosx-10.7-intel.egg/zmq/eventloop/ioloop.py", line 434, in _run_callback
callback()
File "/Library/Python/2.7/site-packages/tornado/iostream.py", line 304, in wrapper
callback(*args)
File "/Library/Python/2.7/site-packages/tornado/httpserver.py", line 262, in _on_headers
self.request_callback(self._request)
File "/Library/Python/2.7/site-packages/tornado/web.py", line 1412, in __call__
handler._execute(transforms, *args, **kwargs)
File "/Library/Python/2.7/site-packages/tornado/web.py", line 1025, in _execute
self._handle_request_exception(e)
File "/Library/Python/2.7/site-packages/tornado/web.py", line 1065, in _handle_request_exception
self.send_error(500, exc_info=sys.exc_info())
File "/Library/Python/2.7/site-packages/tornado/web.py", line 720, in send_error
self.finish()
File "/Library/Python/2.7/site-packages/tornado/web.py", line 700, in finish
self.flush(include_footers=True)
File "/Library/Python/2.7/site-packages/tornado/web.py", line 660, in flush
self.request.write(headers + chunk, callback=callback)
File "/Library/Python/2.7/site-packages/tornado/httpserver.py", line 429, in write
self.connection.write(chunk, callback=callback)
File "/Library/Python/2.7/site-packages/tornado/httpserver.py", line 177, in write
assert self._request, "Request closed"
AssertionError: Request closed
NOTE：看來它是pyzmq rel因爲排除pyzmq ioloop後會消失。
服務器不死，它可以被其他客戶端使用，所以問題並不重要。儘管如此，在日誌文件中發現這些巨大的混淆痕跡非常煩人。
那麼，有沒有什麼衆所周知的方法來解決這個問題？ 謝謝。