I'd recommend taking a look at the ordering service FAQ. When the ordering service returns an error of:
SERVICE_UNAVAILABLE
this almost always indicates a connection problem between the orderer and Kafka. This is usually due to one of two reasons:
- The ordering service has not been given long enough to startup and Kafka is still performing leader election.
- The Kafka cluster is misconfigured.
I would always encourage users to first become familiar with Kafka. Get the cluster up and running, and send receive messages to/from it, including from other hosts or containers, just like your orderer process will. Only then should you attempt to deploy Fabric on top of Kafka. There is a quickstart guide offered by Kafka which is a good place to start.