[YARN-9824] Fall back to configured queue ordering policy class name

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.10.0, 3.3.0, 3.2.2, 3.1.4
• Labels: release-blocker
• Target Version/s: 2.10.0
• Assignee: Jonathan Hung
• Reporter: Jonathan Hung
• Created: 09/Sep/19 20:15
• Updated: 10/Sep/19 22:42
• Resolved: 10/Sep/19 22:42

Description

Currently this is how configured queue ordering policy is determined:

if (policyType.trim().equals(QUEUE_UTILIZATION_ORDERING_POLICY)) {
  // Doesn't respect priority
  qop = new PriorityUtilizationQueueOrderingPolicy(false);
} else if (policyType.trim().equals(
    QUEUE_PRIORITY_UTILIZATION_ORDERING_POLICY)) {
  qop = new PriorityUtilizationQueueOrderingPolicy(true);
} else {
  String message =
      "Unable to construct queue ordering policy=" + policyType + " queue="
          + queue;
  throw new YarnRuntimeException(message);
} 

If we want to enable a policy which is not QUEUE_UTILIZATION_ORDERING_POLICY or QUEUE_PRIORITY_UTILIZATION_ORDERING_POLICY, it requires code change here to add a keyword for this policy.

It'd be easier if the admin could configure a class name here instead of requiring a keyword.