up default max_msg_size to 1MB

IPython/html/notebookapp.py

@@ -295,8 +295,8 b' class NotebookApp(BaseIPythonApplication):'
 
     kernel_argv = List(Unicode)
 
-    max_msg_size = Integer(65536, config=True, help="""
-        The max raw message size accepted from the browser
+    max_msg_size = Integer(2**20, config=True, help="""
+        The max raw message size (in bytes) accepted from the browser
         over a WebSocket connection.
     """)
 

IPython/html/services/kernels/handlers.py

@@ -81,7 +81,7 b' class ZMQChannelHandler(AuthenticatedZMQStreamHandler):'
     
     @property
     def max_msg_size(self):
-        return self.settings.get('max_msg_size', 65535)
+        return self.settings.get('max_msg_size', 2**20)
     
     def create_stream(self):
         km = self.kernel_manager