I'm writing a Flask server using SSE and running into the same problem as Flask server sent events socket exception. Looking for better answers because leaving the client responsible is not good if the for example the browser does not exit gracefully.
Within the context of code from the question above, the Flask server sends events to the client using a Response of mimetype="text/event-stream" and the response object is just a co-routine which continuously yields data. If a client disconnects without calling close(), the server gets an exception Errno 32 Broken Pipe.
Putting a try around the return statement catches an error, but it doesnt stop the log below from printing:
Traceback (most recent call last):
File "/Users/miluo/development/build/venv/lib/python2.6/site-packages/gevent/pywsgi.py", line 508, in handle_one_response
self.run_application()
File "/Users/miluo/development/build/venv/lib/python2.6/site-packages/gevent/pywsgi.py", line 495, in run_application
self.process_result()
File "/Users/miluo/development/build/venv/lib/python2.6/site-packages/gevent/pywsgi.py", line 486, in process_result
self.write(data)
File "/Users/miluo/development/build/venv/lib/python2.6/site-packages/gevent/pywsgi.py", line 376, in write
self._write(data)
File "/Users/miluo/development/build/venv/lib/python2.6/site-packages/gevent/pywsgi.py", line 369, in _write
self._sendall(data)
File "/Users/miluo/development/build/venv/lib/python2.6/site-packages/gevent/pywsgi.py", line 355, in _sendall
self.socket.sendall(data)
File "/Users/miluo/development/build/venv/lib/python2.6/site-packages/gevent/socket.py", line 460, in sendall
data_sent += self.send(_get_memory(data, data_sent), flags)
File "/Users/miluo/development/build/venv/lib/python2.6/site-packages/gevent/socket.py", line 437, in send
return sock.send(data, flags)
error: [Errno 32] Broken pipe
{'GATEWAY_INTERFACE': 'CGI/1.1',
'HTTP_ACCEPT': 'text/event-stream',
'HTTP_ACCEPT_ENCODING': 'gzip, deflate, sdch',
'HTTP_ACCEPT_LANGUAGE': 'en-US,en;q=0.8',
'HTTP_CACHE_CONTROL': 'no-cache',
'HTTP_CONNECTION': 'keep-alive',
'HTTP_HOST': '0.0.0.0:1234',
'HTTP_ORIGIN': 'localhost:1122',
'HTTP_REFERER': 'localhost:1122/',
'HTTP_USER_AGENT': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/48.0.2564.103 Safari/537.36',
'PATH_INFO': '/1',
'QUERY_STRING': '',
'REMOTE_ADDR': '127.0.0.1',
'REMOTE_PORT': '51323',
'REQUEST_METHOD': 'GET',
'SCRIPT_NAME': '',
'SERVER_NAME': 'localhost',
'SERVER_PORT': '1234',
'SERVER_PROTOCOL': 'HTTP/1.1',
'SERVER_SOFTWARE': 'gevent/1.0 Python/2.6',
'werkzeug.request': None,
'wsgi.errors': <open file '<stderr>', mode 'w' at 0x105c991e0>,
'wsgi.input': <gevent.pywsgi.Input object at 0x10753a5d0>,
'wsgi.multiprocess': False,
'wsgi.multithread': False,
'wsgi.run_once': False,
'wsgi.url_scheme': 'http',
'wsgi.version': (1, 0)} failed with error
