YARN-9360. Do not expose innards of QueueMetrics object into FSLeafQueue#computeMaxAMResource. Contributed by Peter Bacsko

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/QueueMetrics.java

@@ -833,7 +833,37 @@ public class QueueMetrics implements MetricsSource {
     return aggregateContainersPreempted.value();
   }
 
-  public QueueMetricsForCustomResources getQueueMetricsForCustomResources() {
-    return queueMetricsForCustomResources;
+  /**
+   * Fills in Resource values from available metrics values of custom resources
+   * to @code{targetResource}, only if the corresponding
+   * value of @code{targetResource} is zero.
+   * If @code{fromResource} has a value less than the available metrics value
+   * for a particular resource, it will be set to the @code{targetResource}
+   * instead.
+   *
+   * @param fromResource The resource to compare available resource values with.
+   * @param targetResource The resource to save the values into.
+   */
+  public void fillInValuesFromAvailableResources(Resource fromResource,
+      Resource targetResource) {
+    if (queueMetricsForCustomResources != null) {
+      QueueMetricsCustomResource availableResources =
+          queueMetricsForCustomResources.getAvailable();
+
+      // We expect all custom resources contained in availableResources,
+      // so we will loop through all of them.
+      for (Map.Entry<String, Long> availableEntry : availableResources
+          .getValues().entrySet()) {
+        String resourceName = availableEntry.getKey();
+
+        // We only update the value if fairshare is 0 for that resource.
+        if (targetResource.getResourceValue(resourceName) == 0) {
+          Long availableValue = availableEntry.getValue();
+          long value = Math.min(availableValue,
+              fromResource.getResourceValue(resourceName));
+          targetResource.setResourceValue(resourceName, value);
+        }
+      }
+    }
   }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/FSLeafQueue.java

@@ -23,7 +23,6 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
-import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReadWriteLock;
@@ -43,8 +42,6 @@ import org.apache.hadoop.yarn.api.records.QueueUserACLInfo;
 import org.apache.hadoop.yarn.api.records.Resource;
 import org.apache.hadoop.yarn.server.resourcemanager.rmcontainer.RMContainer;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.ActiveUsersManager;
-import org.apache.hadoop.yarn.server.resourcemanager.scheduler.QueueMetricsCustomResource;
-import org.apache.hadoop.yarn.server.resourcemanager.scheduler.QueueMetricsForCustomResources;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.SchedulerAppUtils;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.SchedulerApplicationAttempt;
 import org.apache.hadoop.yarn.util.resource.Resources;
@@ -507,40 +504,22 @@ public class FSLeafQueue extends FSQueue {
   */
   private Resource computeMaxAMResource() {
     Resource maxResource = Resources.clone(getFairShare());
+    Resource maxShare = getMaxShare();
+
     if (maxResource.getMemorySize() == 0) {
       maxResource.setMemorySize(
           Math.min(scheduler.getRootQueueMetrics().getAvailableMB(),
-                   getMaxShare().getMemorySize()));
+                   maxShare.getMemorySize()));
     }
 
     if (maxResource.getVirtualCores() == 0) {
       maxResource.setVirtualCores(Math.min(
           scheduler.getRootQueueMetrics().getAvailableVirtualCores(),
-          getMaxShare().getVirtualCores()));
+          maxShare.getVirtualCores()));
     }
 
-    QueueMetricsForCustomResources metricsForCustomResources =
-        scheduler.getRootQueueMetrics().getQueueMetricsForCustomResources();
-
-    if (metricsForCustomResources != null) {
-      QueueMetricsCustomResource availableResources =
-          metricsForCustomResources.getAvailable();
-
-      // We expect all custom resources contained in availableResources,
-      // so we will loop through all of them.
-      for (Map.Entry<String, Long> availableEntry : availableResources
-          .getValues().entrySet()) {
-        String resourceName = availableEntry.getKey();
-
-        // We only update the value if fairshare is 0 for that resource.
-        if (maxResource.getResourceValue(resourceName) == 0) {
-          Long availableValue = availableEntry.getValue();
-          long value = Math.min(availableValue,
-              getMaxShare().getResourceValue(resourceName));
-          maxResource.setResourceValue(resourceName, value);
-        }
-      }
-    }
+    scheduler.getRootQueueMetrics()
+        .fillInValuesFromAvailableResources(maxShare, maxResource);
 
     // Round up to allow AM to run when there is only one vcore on the cluster
     return Resources.multiplyAndRoundUp(maxResource, maxAMShare);