Cruise Control with Kafka behind load balancers and a single host name

[christian-ertl]

We use as Kafka cluster an AWS MSK which uses network load balancers to allow the use a different host name than the ones provided by AWS: The advertised listeners are reconfigured to return the same host name with different ports for each broker. (Cf. AWS solution article, pattern 2)

It appears Cruise Control currently does not support this use case.

From looking at the code of the PrometheusMetricSampler, I assume that our use case is currently not supported by Cruise Control as there only the host name is considered, but not the port. Since Prometheus actually returns the true host names, all the metrics are also skipped (which could probably be solved by scrape config).