Comment by neomantra

It’s easy to focus on the reliable UDP protocol and the multicast support, but what’s important about Aeron is its system architecture. As noted elsewhere, it all combines together in “mechanical sympathy” and once you have that you can interconnect with high performance transports [1].

So you set up an Aeron Server on your machine. That handles all external network communication at the message layer (NAKs, etc). Every “Aeron Client” process communicates with that Server to stand up shared memory pipes. The messaging client solely deals with those pipes (cache efficient, etc). They subscribe to channels at host:port/topic but it is not direct network delivery to them (the client is transport agnostic, besides the subscription). The network service directs data to the clients shared memory queue.

Once they have that base networked-IPC setup, you can maximize performance with it using reliable UDP and fan out common data (eg marlet data) using multicast.

Then Aeron further adds Archiving (to persist) and Clustering (to scale late join / state replication) components. This stuff works well with kernel bypass :)

[1] It could work with RDMA as well, but the ticket regarding that was closed 8 years ago. Maybe if there was AI/GPU workload interest.