min.insync.replicas=2, but the topic only has one replica.
If you have
request.required.acks=all (which is the default), then the producer will fail because it cannot replicate what you've produced to the leader broker to the minimum set of required replicas
I believe console producer only sets that property to just 1
there are 3
There's actually only one. That's broker ID 3. You'd see a total of three separate numbers there as ISR if there were actually three replicas