What are the main differences between Netty and JGroups?

Question

JGroups seems to be in existence since late 90's. Why do we need Netty when we have JGroups? Is it because JGroups is based on thread pooling while Netty is asynchronous? Is that the only difference?

Answer 1

Netty is a general purpose network framework with which you can write "any" network related application. So it is much more generic then JGroups.

Answer 2

JGroupss goal is clustering and reliable messaging, with a focus on group communication, ie. sending messages to a group of nodes (one-to-many). Its mainly used to implement decentralized peer-to-peer systems.

Netty's focus is (afaict) point to point messaging (one-to-one). A typical implementation would be a client-server architecture.

Disclaimer: I'm the JGroups lead, and don't know too much about Netty...