Use gunicorn as the default webserver

app/corpora/events.py

@@ -59,7 +59,7 @@ def corpus_analysis_session_handler(app, corpus_id, user_id, session_id):
             retry_counter -= 1
             if retry_counter == 0:
                 response = {'code': 408, 'desc': None, 'msg': 'Request Timeout'}  # noqa
-                socketio.emit('corpus_analysis_init', response, room=request.sid)  # noqa
+                socketio.emit('corpus_analysis_init', response, room=session_id)  # noqa
                 corpus.status = 'stop analysis'
                 db.session.commit()
                 return