YARN-11646. Do not ignore zero memory capacity config in QueueCapacityConfigParser. (#6433)

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/conf/QueueCapacityConfigParser.java

@@ -148,11 +148,6 @@ public class QueueCapacityConfigParser {
       }
     }
 
-    // Memory always have to be defined
-    if (capacityVector.getMemory() == 0L) {
-      return new QueueCapacityVector();
-    }
-
     return capacityVector;
   }
 

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/conf/TestQueueCapacityConfigParser.java

@@ -214,4 +214,19 @@ public class TestQueueCapacityConfigParser {
         Lists.newArrayList(nonSetCapacity.iterator());
     Assert.assertEquals(nonSetResources.size(), 0);
   }
-}
+
+  @Test
+  public void testZeroAbsoluteCapacityConfig() {
+    QueueCapacityVector weightCapacityVector =
+        capacityConfigParser.parse(String.format(MEMORY_VCORE_TEMPLATE, 0, 0), QUEUE);
+
+    QueueCapacityVectorEntry memory = weightCapacityVector.getResource(MEMORY_URI);
+    QueueCapacityVectorEntry vcore = weightCapacityVector.getResource(VCORES_URI);
+
+    Assert.assertEquals(ResourceUnitCapacityType.ABSOLUTE, memory.getVectorResourceType());
+    Assert.assertEquals(0, memory.getResourceValue(), EPSILON);
+
+    Assert.assertEquals(ResourceUnitCapacityType.ABSOLUTE, vcore.getVectorResourceType());
+    Assert.assertEquals(0, vcore.getResourceValue(), EPSILON);
+  }
+}