Yes you are right when you say "Reliable UDP isn’t a defined standard". However, there are some protocols has implemented using UDP. For example, some Red Hat apps, protocols, and framework implemented using reliable UDP (their own reliable UDP), and they works fast and reliable.
To answer your question, "what sort of improvements would you expect from it, over TCP?" Zookeeper uses TCP protocol to send/receive messages. For example, when the leader sends proposal to 4 followers, it sends it one by one, meaning that it needs to send 4 messages (four outgoing packets). Whereas, to achieve same thing using RUDP (IP multicast), here leader only needs to send one messages (one outgoing packets), as a result, it reduces the network traffic. Thank you Ibrahim -- View this message in context: http://zookeeper-user.578899.n2.nabble.com/Why-ZK-uses-TCP-instead-of-UPD-IP-multicast-tp7580715p7580717.html Sent from the zookeeper-user mailing list archive at Nabble.com.
