YARN-415 we have the ability to track the resource*time footprint of a job and preemption metrics shows how many containers were preempted on a job. However we don't have a metric showing the resource*time footprint cost of preemption. In other words, we know how many containers were preempted but we don't have a good measure of how much work was lost as a result of preemption.
We should add this metric so we can analyze how much work preemption is costing on a grid and better track which jobs were heavily impacted by it. A job that has 100 containers preempted that only lasted a minute each and were very small is going to be less impacted than a job that only lost a single container but that container was huge and had been running for 3 days.