Blocker Description
QueueMetrics for ResourceManager do not have any metrics for aggregate containers-allocated and containers-released.
We need the aggregates of containers-allocated and containers-released to figure out the rate at which RM is dishing out containers. NodeManager do have containers-launched and container-released metrics, but this is not across all nodes; so to get the cluster level aggregate, we need to preprocess NM metrics from all nodes - which is troublesome.
Currently, we do have AllocatedContainers and PendingContainers which reflect the running containers given out to AMs, and containers waiting for allocation respectively.