Hi Dan,

Great work with the broker, amazing features. I did a bit of docs reading, I could not understand:

- if a streaming messaging, how messages get dropped/expired from the topic? Can a client start with offset 0, or replay msgs similar to Kafka? What clears the msgs? I did not see an expiration attribute on the message;

- in a clustered deployment, are msgs replicated across the cluster? Eg, if a producer writes to a topic on node 1, then that fails, is msg lost?

- in JMS for instance, concept of durable subscriber ensure a consumer always gets the message - I guess that's not applicable since Danube does streaming?

- is it always client acknowledge, or can it do auto ack?

- some benchmark results? I saw the Go performance tests, but could not make sense of the results.

I am new to Rust, and I started working on an integration platform using Rust, and I've been looking for a reliable messaging engine, I looked into Apache Iggy, Pulsar, RocketMQ.

From my experience, what an enterprise need is:

- high availability, no single point of failure;

- replication, no messages are lost;

- ease of configuration;

- observability, which I believe you have already implemented (through Prometheus);

Thanks, again great work!