How to use

computeIdealResourceDistribution

method

in

org.apache.hadoop.yarn.server.resourcemanager.monitor.capacity.ProportionalCapacityPreemptionPolicy

/**
 * This method recursively computes the ideal assignment of resources to each
 * level of the hierarchy. This ensures that leafs that are over-capacity but
 * with parents within capacity will not be preempted. Preemptions are allowed
 * within each subtree according to local over/under capacity.
 *
 * @param root the root of the cloned queue hierachy
 * @param totalPreemptionAllowed maximum amount of preemption allowed
 * @return a list of leaf queues updated with preemption targets
 */
private List<TempQueue> recursivelyComputeIdealAssignment(
  TempQueue root, Resource totalPreemptionAllowed) {
 List<TempQueue> leafs = new ArrayList<TempQueue>();
 if (root.getChildren() != null &&
   root.getChildren().size() > 0) {
  // compute ideal distribution at this level
  computeIdealResourceDistribution(rc, root.getChildren(),
    totalPreemptionAllowed, root.idealAssigned);
  // compute recursively for lower levels and build list of leafs
  for(TempQueue t : root.getChildren()) {
   leafs.addAll(recursivelyComputeIdealAssignment(t, totalPreemptionAllowed));
  }
 } else {
  // we are in a leaf nothing to do, just return yourself
  return Collections.singletonList(root);
 }
 return leafs;
}

/**
 * This method recursively computes the ideal assignment of resources to each
 * level of the hierarchy. This ensures that leafs that are over-capacity but
 * with parents within capacity will not be preempted. Preemptions are allowed
 * within each subtree according to local over/under capacity.
 *
 * @param root the root of the cloned queue hierachy
 * @param totalPreemptionAllowed maximum amount of preemption allowed
 * @return a list of leaf queues updated with preemption targets
 */
private List<TempQueue> recursivelyComputeIdealAssignment(
  TempQueue root, Resource totalPreemptionAllowed) {
 List<TempQueue> leafs = new ArrayList<TempQueue>();
 if (root.getChildren() != null &&
   root.getChildren().size() > 0) {
  // compute ideal distribution at this level
  computeIdealResourceDistribution(rc, root.getChildren(),
    totalPreemptionAllowed, root.idealAssigned);
  // compute recursively for lower levels and build list of leafs
  for(TempQueue t : root.getChildren()) {
   leafs.addAll(recursivelyComputeIdealAssignment(t, totalPreemptionAllowed));
  }
 } else {
  // we are in a leaf nothing to do, just return yourself
  return Collections.singletonList(root);
 }
 return leafs;
}