HDFS-9839. Reduce verbosity of processReport logging. (Contributed by Arpit Agarwal)

This closes #78

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -2802,6 +2802,8 @@ Release 2.8.0 - UNRELEASED
     HDFS-6832. Fix the usage of 'hdfs namenode' command.
     (Manjunath Ballur via aajisaka)
 
+    HDFS-9839. Reduce verbosity of processReport logging. (Arpit Agarwal)
+
 Release 2.7.3 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockManager.java

@@ -2060,7 +2060,7 @@ public class BlockManager implements BlockStatsMXBean {
     final long startTime = Time.monotonicNow(); //after acquiring write lock
     final long endTime;
     DatanodeDescriptor node;
-    Collection<Block> invalidatedBlocks = null;
+    Collection<Block> invalidatedBlocks = Collections.emptyList();
 
     try {
       node = datanodeManager.getDatanode(nodeID);
@@ -2136,11 +2136,9 @@ public class BlockManager implements BlockStatsMXBean {
       namesystem.writeUnlock();
     }
 
-    if (invalidatedBlocks != null) {
-      for (Block b : invalidatedBlocks) {
-        blockLog.info("BLOCK* processReport: {} on node {} size {} does not " +
-            "belong to any file", b, node, b.getNumBytes());
-      }
+    for (Block b : invalidatedBlocks) {
+      blockLog.debug("BLOCK* processReport: {} on node {} size {} does not " +
+          "belong to any file", b, node, b.getNumBytes());
     }
 
     // Log the block report processing stats from Namenode perspective
@@ -2149,9 +2147,11 @@ public class BlockManager implements BlockStatsMXBean {
       metrics.addBlockReport((int) (endTime - startTime));
     }
     blockLog.info("BLOCK* processReport: from storage {} node {}, " +
-            "blocks: {}, hasStaleStorage: {}, processing time: {} msecs", storage
-            .getStorageID(), nodeID, newReport.getNumberOfBlocks(),
-        node.hasStaleStorages(), (endTime - startTime));
+        "blocks: {}, hasStaleStorage: {}, processing time: {} msecs, " +
+        "invalidatedBlocks: {}", storage.getStorageID(), nodeID,
+        newReport.getNumberOfBlocks(),
+        node.hasStaleStorages(), (endTime - startTime),
+        invalidatedBlocks.size());
     return !node.hasStaleStorages();
   }