Broker.xml (host1) and host2 just the port number changes to 61616 and slave as configuration. In reference with Apache Artemis client fail over discovery
The error stating "Unblocking a blocking call that will never get a response" is expected if failover happens when the client is in the middle of a blocking call (e.g. sending a durable message and waiting for an ack from the broker, committing a transaction, etc.). This is discussed further in the documentation.
The fact that clients don't switch back to the master broker when it comes back is also expected given your configuration. In short, you haven't configured failback properly. Your master should have:
true
And your slave should have:
true
This is also discussed in the documentation.
Lastly, you do not need to configure the broadcast and discovery groups when using a static connector.