Comment 4 for bug 1701061

DEBUG:runner:Cluster status of node 'rabbit@juju-4d268d-auto-osci-sv06-16' ...
DEBUG:runner:[{nodes,[{disc,['rabbit@juju-4d268d-auto-osci-sv06-15',
DEBUG:runner: 'rabbit@juju-4d268d-auto-osci-sv06-16']}]},
DEBUG:runner: {running_nodes,['rabbit@juju-4d268d-auto-osci-sv06-15',
DEBUG:runner: 'rabbit@juju-4d268d-auto-osci-sv06-16']},
DEBUG:runner: {cluster_name,<<"rabbit@juju-4d268d-auto-osci-sv06-17">>},
DEBUG:runner: {partitions,[]}]
DEBUG:runner:['Cluster registration check failed on rabbitmq-server/6: rabbit@juju-4d268d-auto-osci-sv06-17 should not be registered with RabbitMQ after unit removal.\n']
DEBUG:runner:Exit Code: 1

As you can see here the test itself is clearly in error mistaking value of cluster_name for a node. Making the test sleep will not change that, so it's passing is random with regards to which node was removed.

So should do two things:
1) Update the functional test to not mistake cluster_name as a node in the cluster
2) Evaluate thoroughly whether we should update cluster_name on leader change

I believe 2) is not really necessary and I avoided updating the cluster name in the fixes for bug 1679449 since I did not have full view of what side effects that could have at the time.

As for bug 1691510 and the related fixes, it is not clear to me how that code is using cluster_name for anything?