Upgrading to Flask-SocketIO 5.x from the 4.x releases¶
The following protocol changes are of importance, as they may affect existing applications:
The default namespace
'/'is not automatically connected anymore, and is now treated in the same way as other namespaces.
Each namespace connection has its own
sidvalue, different from the others and different from the Engine.IO
The ping/pong mechanism has been reversed. In the current version of the protocol, the server issues a ping and the client responds with a pong.
The default allowed payload size for long–polling packets has been lowered from 100MB to 1MB.
The io cookie is not sent to the client anymore by default.