If anyone is curious to try exporting Spark metrics to Graphite, I just published a post about my experience doing that, building dashboards in Grafana <http://grafana.org/>, and using them to monitor Spark jobs: http://www.hammerlab.org/2015/02/27/monitoring-spark-with-graphite-and-grafana/
Code for generating Grafana dashboards tailored to the metrics emitted by Spark is here: https://github.com/hammerlab/grafana-spark-dashboards. If anyone else is interested in working on expanding MetricsSystem to make this sort of thing more useful, let me know, I've been working on it a fair amount and have a bunch of ideas about where it should go. Thanks, -Ryan
