YARN-6082. Invalid REST api response for getApps since queueUsagePercentage is coming as INF. Contributed by Sunil G.

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

@@ -1037,9 +1037,12 @@ public class SchedulerApplicationAttempt implements SchedulableEntity {
       float queueUsagePerc = 0.0f;
       float clusterUsagePerc = 0.0f;
       if (!calc.isInvalidDivisor(cluster)) {
-        queueUsagePerc = calc.divide(cluster, usedResourceClone, Resources
-            .multiply(cluster, queue.getQueueInfo(false, false).getCapacity()))
-            * 100;
+        float queueCapacityPerc = queue.getQueueInfo(false, false)
+            .getCapacity();
+        if (queueCapacityPerc != 0) {
+          queueUsagePerc = calc.divide(cluster, usedResourceClone,
+              Resources.multiply(cluster, queueCapacityPerc)) * 100;
+        }
         clusterUsagePerc = calc.divide(cluster, usedResourceClone, cluster)
             * 100;
       }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/TestSchedulerApplicationAttempt.java

@@ -227,6 +227,18 @@ public class TestSchedulerApplicationAttempt {
         0.01f);
     assertEquals(60.0f,
         app.getResourceUsageReport().getClusterUsagePercentage(), 0.01f);
+
+    queue = createQueue("test3", null, 0.0f);
+    app = new SchedulerApplicationAttempt(appAttId, user, queue,
+        queue.getActiveUsersManager(), rmContext);
+
+    // Resource request
+    app.attemptResourceUsage.incUsed(requestedResource);
+
+    assertEquals(0.0f, app.getResourceUsageReport().getQueueUsagePercentage(),
+        0.01f);
+    assertEquals(15.0f,
+        app.getResourceUsageReport().getClusterUsagePercentage(), 0.01f);
   }
 
   @Test