YARN-10430. Log improvements in NodeStatusUpdaterImpl. Contributed by Bilwa S T.

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/NodeStatusUpdaterImpl.java

@@ -403,12 +403,10 @@ public class NodeStatusUpdaterImpl extends AbstractService implements
         List<LogAggregationReport> logAggregationReports =
             context.getNMLogAggregationStatusTracker()
                 .pullCachedLogAggregationReports();
-        if (LOG.isDebugEnabled()) {
-          LOG.debug("The cache log aggregation status size:"
-              + logAggregationReports.size());
-        }
         if (logAggregationReports != null
             && !logAggregationReports.isEmpty()) {
+          LOG.debug("The cache log aggregation status size:{}",
+              logAggregationReports.size());
           request.setLogAggregationReportsForApps(logAggregationReports);
         }
       }
@@ -621,11 +619,11 @@ public class NodeStatusUpdaterImpl extends AbstractService implements
     }
 
     containerStatuses.addAll(pendingCompletedContainers.values());
-
-    if (LOG.isDebugEnabled()) {
-      LOG.debug("Sending out " + containerStatuses.size()
-          + " container statuses: " + containerStatuses);
+    if (!containerStatuses.isEmpty()) {
+      LOG.debug("Sending out {} container statuses: {}",
+          containerStatuses.size(), containerStatuses);
     }
+
     return containerStatuses;
   }
 
@@ -663,8 +661,10 @@ public class NodeStatusUpdaterImpl extends AbstractService implements
         addCompletedContainer(containerId);
       }
     }
-    LOG.info("Sending out " + containerStatuses.size()
-      + " NM container statuses: " + containerStatuses);
+    if (!containerStatuses.isEmpty()) {
+      LOG.info("Sending out " + containerStatuses.size()
+          + " NM container statuses: " + containerStatuses);
+    }
     return containerStatuses;
   }