Question

我使用的是用Python 3.5编写的websocket服务器。这是提供我的网站实时信息所必需的。

我使用的“服务器” - 库被称为tornado（version 4.5b2），它处理websocket连接和http请求。为了向后兼容（如果浏览器还不支持websocket）我使用python库sockjs-tornado（版本1.0.3），它还为websocket连接添加了一些额外的功能。

现在我的问题是，如果我启动服务器，我在控制台中会遇到很多龙卷风ssl错误。它不会崩溃，但如果大约有80个客户端连接到websocket 3，则会经常发生错误。我使用加密连接并且它可以工作，但是如果出现其中一个错误，一些客户端会被踢出websocket连接。

Python脚本使用多个线程，服务器受cloudflare保护，cloudflare是某种中间人，并将每个请求重定向到服务器或用户。

这是3个错误：


ERROR:tornado.general:Uncaught exception, closing connection.
Traceback (most recent call last):
  File "/home/website/python/tornado/iostream.py", line 523, in _handle_events
    self._handle_write()
  File "/home/website/python/tornado/iostream.py", line 1398, in _handle_write
    super(SSLIOStream, self)._handle_write()
  File "/home/website/python/tornado/iostream.py", line 847, in _handle_write
    assert self._write_buffer_size >= 0
AssertionError
ERROR:tornado.application:Exception in callback None
Traceback (most recent call last):
  File "/home/website/python/tornado/ioloop.py", line 888, in start
    handler_func(fd_obj, events)
  File "/home/website/python/tornado/stack_context.py", line 277, in null_wrapper
    return fn(*args, **kwargs)
  File "/home/website/python/tornado/iostream.py", line 523, in _handle_events
    self._handle_write()
  File "/home/website/python/tornado/iostream.py", line 1398, in _handle_write
    super(SSLIOStream, self)._handle_write()
  File "/home/website/python/tornado/iostream.py", line 847, in _handle_write
    assert self._write_buffer_size >= 0
AssertionError

此错误不会像第一个错误那样频繁出现。

ERROR:tornado.application:Uncaught exception GET /sockjs/398/ssputw1s/websocket
HTTPServerRequest(protocol='https', host='****.com:8443', method='GET', uri='/sockjs/398/ssputw1s/websocket', version='HTTP/1.1', remote_ip='****', headers={'Accept-Encoding': 'gzip', 'Cf-Visitor': '{"scheme":"https"}', 'Sec-Websocket-Key': '****', 'Host': '****.com:8443', 'X-Forwarded-Proto': 'https', 'Cache-Control': 'no-cache', 'Sec-Websocket-Version': '13', 'Cf-Ipcountry': 'FR', 'X-Forwarded-For': '****', 'Sec-Websocket-Extensions': 'x-webkit-deflate-frame', 'Origin': 'https://****.com', 'Cf-Connecting-Ip': '****', 'Cookie': '****', 'Upgrade': 'websocket', 'Cf-Ray': '34edb1a17c456908-CDG', 'User-Agent': '****', 'Connection': 'Upgrade', 'Pragma': 'no-cache'})
Traceback (most recent call last):
  File "/home/website/python/tornado/web.py", line 1464, in _stack_context_handle_exception
    raise_exc_info((type, value, traceback))
  File "<string>", line 4, in raise_exc_info
  File "/home/website/python/tornado/stack_context.py", line 316, in wrapped
    ret = fn(*args, **kwargs)
  File "/home/website/python/tornado/websocket.py", line 865, in _on_masked_frame_data
    self._on_frame_data(_websocket_mask(self._frame_mask, data))
  File "/home/website/python/tornado/websocket.py", line 910, in _on_frame_data
    self._receive_frame()
  File "/home/website/python/tornado/websocket.py", line 784, in _receive_frame
    self.stream.read_bytes(2, self._on_frame_start)
  File "/home/website/python/tornado/iostream.py", line 324, in read_bytes
    self._try_inline_read()
  File "/home/website/python/tornado/iostream.py", line 711, in _try_inline_read
    pos = self._read_to_buffer_loop()
  File "/home/website/python/tornado/iostream.py", line 625, in _read_to_buffer_loop
    if self._read_to_buffer() == 0:
  File "/home/website/python/tornado/iostream.py", line 738, in _read_to_buffer
    chunk = self.read_from_fd()
  File "/home/website/python/tornado/iostream.py", line 1487, in read_from_fd
    chunk = self.socket.read(self.read_chunk_size)
  File "/usr/lib64/python3.5/ssl.py", line 799, in read
    return self._sslobj.read(len, buffer)
  File "/usr/lib64/python3.5/ssl.py", line 585, in read
    v = self._sslobj.read(len)
ssl.SSLWantWriteError: The operation did not complete (write) (_ssl.c:2090)

有时出现此错误：

ERROR:tornado.general:Uncaught exception, closing connection.
Traceback (most recent call last):
  File "/home/website/python/tornado/iostream.py", line 523, in _handle_events
    self._handle_write()
  File "/home/website/python/tornado/iostream.py", line 1398, in _handle_write
    super(SSLIOStream, self)._handle_write()
  File "/home/website/python/tornado/iostream.py", line 872, in _handle_write
    del self._write_buffer[:self._write_buffer_pos]
BufferError: Existing exports of data: object cannot be re-sized
ERROR:tornado.application:Exception in callback None
Traceback (most recent call last):
  File "/home/website/python/tornado/ioloop.py", line 888, in start
    handler_func(fd_obj, events)
  File "/home/website/python/tornado/stack_context.py", line 277, in null_wrapper
    return fn(*args, **kwargs)
  File "/home/website/python/tornado/iostream.py", line 523, in _handle_events
    self._handle_write()
  File "/home/website/python/tornado/iostream.py", line 1398, in _handle_write
    super(SSLIOStream, self)._handle_write()
  File "/home/website/python/tornado/iostream.py", line 872, in _handle_write
    del self._write_buffer[:self._write_buffer_pos]
BufferError: Existing exports of data: object cannot be re-sized

Answer 1

看起来像库中的错误 - 即竞争条件导致多个实体同时使用相同的写缓冲区。

第一个错误 - _write_buffer_size下溢 - 另一个实体在不合适时从中读取
第3次错误 - buffer in use什么时候不应该

要抓住它，您需要跟踪使用_write_buffer的所有操作并更改_write_buffer_size以及它们来自哪里。

Answer 2

这看起来像是Tornado 4.5b2中的一个错误，正在this issue中讨论。寻找它在4.5b3或4.5 final中修复，同时你可以回到4.4版本。

Python龙卷风SSL websocket连接

2 个答案: