The current interface for attaching metrics reporters to clients allows only defining a list of class names, but provides no means for configuring those reporters.
There is at least one existing project (https://github.com/apakulov/kafka-graphite) that solves this problem by passing additional properties into the client, which then get passed on to the reporter. This seems to work quite well, but it generates warnings like The configuration kafka.graphite.metrics.prefix = foo was supplied but isn't a known config.
Should passing arbitrary additional parameters like this be officially supported as the way to configure metrics reporters? Should these warnings about unrecognized parameters be removed?
Perhaps there should be some mechanism for registering additional configuration parameters for clients to expect?