I'm not familiar with Akka, but both NATS Streaming and Liftbridge sound like they'd fit your purpose.
NATS on its own won't cut it, since it has no persistence and is entirely real-time (new clients receive messages published after they connect, not old messages).
I've not used Liftbridge yet, but plan to. While NATS Streaming is solid, its distributed design seems a bit ramshackle, relying on a combination of Raft and a shared state (a distributed file system or an SQL database) for failover. Liftbridge seems like a better design to me.
NATS on its own won't cut it, since it has no persistence and is entirely real-time (new clients receive messages published after they connect, not old messages).
I've not used Liftbridge yet, but plan to. While NATS Streaming is solid, its distributed design seems a bit ramshackle, relying on a combination of Raft and a shared state (a distributed file system or an SQL database) for failover. Liftbridge seems like a better design to me.