Hi there and thanks for a wonderful project.
I am using https://prometheus.io/ to collect metrics from the various components of our clusters.
Prometheus expects an http endpoint where metrics are exposed using the Prometheus format.
Alluxio already exposes the codahale metrics formatted as JSON.
This new feature consists of exposing the same metrics formatted for Prometheus.
In fact Prometheus provides a java library and an adapter to format codehale metrics as prometheus metrics.
I am making a pull request on github.