diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockManager.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockManager.java
index 51e12ec433..469911df2c 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockManager.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockManager.java
@@ -1893,8 +1893,10 @@ private void markBlockAsCorrupt(BlockToMarkCorrupt b,
       DatanodeStorageInfo storageInfo,
       DatanodeDescriptor node) throws IOException {
     if (b.getStored().isDeleted()) {
-      blockLog.debug("BLOCK markBlockAsCorrupt: {} cannot be marked as" +
-          " corrupt as it does not belong to any file", b);
+      if(blockLog.isDebugEnabled()) {
+        blockLog.debug("BLOCK markBlockAsCorrupt: {} cannot be marked as" +
+            " corrupt as it does not belong to any file", b);
+      }
       addToInvalidates(b.getCorrupted(), node);
       return;
     }
@@ -1975,10 +1977,12 @@ private boolean invalidateBlock(BlockToMarkCorrupt b, DatanodeInfo dn,
 
     // Check how many copies we have of the block
     if (nr.replicasOnStaleNodes() > 0 && !deleteCorruptReplicaImmediately) {
-      blockLog.debug("BLOCK* invalidateBlocks: postponing " +
-          "invalidation of {} on {} because {} replica(s) are located on " +
-          "nodes with potentially out-of-date block reports", b, dn,
-          nr.replicasOnStaleNodes());
+      if(blockLog.isDebugEnabled()) {
+        blockLog.debug("BLOCK* invalidateBlocks: postponing " +
+            "invalidation of {} on {} because {} replica(s) are located on " +
+            "nodes with potentially out-of-date block reports", b, dn,
+            nr.replicasOnStaleNodes());
+      }
       postponeBlock(b.getCorrupted());
       return false;
     } else {
@@ -2220,8 +2224,10 @@ BlockReconstructionWork scheduleReconstruction(BlockInfo block,
     int pendingNum = pendingReconstruction.getNumReplicas(block);
     if (hasEnoughEffectiveReplicas(block, numReplicas, pendingNum)) {
       neededReconstruction.remove(block, priority);
-      blockLog.debug("BLOCK* Removing {} from neededReconstruction as" +
-          " it has enough replicas", block);
+      if(blockLog.isDebugEnabled()) {
+        blockLog.debug("BLOCK* Removing {} from neededReconstruction as" +
+            " it has enough replicas", block);
+      }
       NameNode.getNameNodeMetrics().incNumTimesReReplicationNotScheduled();
       return null;
     }
@@ -2317,8 +2323,10 @@ boolean validateReconstructionWork(BlockReconstructionWork rw) {
     if (hasEnoughEffectiveReplicas(block, numReplicas, pendingNum)) {
       neededReconstruction.remove(block, priority);
       rw.resetTargets();
-      blockLog.debug("BLOCK* Removing {} from neededReconstruction as" +
-          " it has enough replicas", block);
+      if(blockLog.isDebugEnabled()) {
+        blockLog.debug("BLOCK* Removing {} from neededReconstruction as" +
+            " it has enough replicas", block);
+      }
       return false;
     }
 
@@ -2349,8 +2357,10 @@ boolean validateReconstructionWork(BlockReconstructionWork rw) {
     // The reason we use 'pending' is so we can retry
     // reconstructions that fail after an appropriate amount of time.
     pendingReconstruction.increment(block, targets);
-    blockLog.debug("BLOCK* block {} is moved from neededReconstruction to "
-        + "pendingReconstruction", block);
+    if(blockLog.isDebugEnabled()) {
+      blockLog.debug("BLOCK* block {} is moved from neededReconstruction to "
+          + "pendingReconstruction", block);
+    }
 
     int numEffectiveReplicas = numReplicas.liveReplicas() + pendingNum;
     // remove from neededReconstruction
@@ -2896,9 +2906,11 @@ public boolean processReport(final DatanodeID nodeID,
 
     if(blockLog.isDebugEnabled()) {
       for (Block b : invalidatedBlocks) {
-        blockLog.debug("BLOCK* processReport 0x{} with lease ID 0x{}: {} on node {} size {} " +
-                        "does not belong to any file.", strBlockReportId, fullBrLeaseId, b,
-                         node, b.getNumBytes());
+        if(blockLog.isDebugEnabled()) {
+          blockLog.debug("BLOCK* processReport 0x{} with lease ID 0x{}: {} on node {} size {} " +
+                          "does not belong to any file.", strBlockReportId, fullBrLeaseId, b,
+                           node, b.getNumBytes());
+        }
       }
     }
 
@@ -3056,9 +3068,11 @@ public void markBlockReplicasAsCorrupt(Block oldBlock,
         }
       }
       if (isCorrupt) {
-        blockLog.debug("BLOCK* markBlockReplicasAsCorrupt: mark block replica" +
-            " {} on {} as corrupt because the dn is not in the new committed " +
-            "storage list.", b, storage.getDatanodeDescriptor());
+        if(blockLog.isDebugEnabled()) {
+          blockLog.debug("BLOCK* markBlockReplicasAsCorrupt: mark block replica" +
+              " {} on {} as corrupt because the dn is not in the new committed " +
+              "storage list.", b, storage.getDatanodeDescriptor());
+        }
         markBlockAsCorrupt(b, storage, storage.getDatanodeDescriptor());
       }
     }
@@ -3575,8 +3589,10 @@ private Block addStoredBlock(final BlockInfo block,
     }
     if (storedBlock == null || storedBlock.isDeleted()) {
       // If this block does not belong to anyfile, then we are done.
-      blockLog.debug("BLOCK* addStoredBlock: {} on {} size {} but it does not" +
-          " belong to any file", block, node, block.getNumBytes());
+      if(blockLog.isDebugEnabled()) {
+        blockLog.debug("BLOCK* addStoredBlock: {} on {} size {} but it does not" +
+            " belong to any file", block, node, block.getNumBytes());
+      }
 
       // we could add this block to invalidate set of this datanode.
       // it will happen in next block report otherwise.
@@ -3605,9 +3621,11 @@ private Block addStoredBlock(final BlockInfo block,
       corruptReplicas.removeFromCorruptReplicasMap(block, node,
           Reason.GENSTAMP_MISMATCH);
       curReplicaDelta = 0;
-      blockLog.debug("BLOCK* addStoredBlock: Redundant addStoredBlock request"
-              + " received for {} on node {} size {}", storedBlock, node,
-          storedBlock.getNumBytes());
+      if(blockLog.isDebugEnabled()) {
+        blockLog.debug("BLOCK* addStoredBlock: Redundant addStoredBlock request"
+                + " received for {} on node {} size {}", storedBlock, node,
+            storedBlock.getNumBytes());
+      }
     }
 
     // Now check for completion of blocks and safe block count
@@ -3708,8 +3726,10 @@ private void invalidateCorruptReplicas(BlockInfo blk, Block reported,
           removedFromBlocksMap = false;
         }
       } catch (IOException e) {
-        blockLog.debug("invalidateCorruptReplicas error in deleting bad block"
-            + " {} on {}", blk, node, e);
+        if(blockLog.isDebugEnabled()) {
+          blockLog.debug("invalidateCorruptReplicas error in deleting bad block"
+              + " {} on {}", blk, node, e);
+        }
         removedFromBlocksMap = false;
       }
     }
@@ -4158,8 +4178,10 @@ private void processChosenExcessRedundancy(
     //
     final Block blockToInvalidate = getBlockOnStorage(storedBlock, chosen);
     addToInvalidates(blockToInvalidate, chosen.getDatanodeDescriptor());
-    blockLog.debug("BLOCK* chooseExcessRedundancies: "
-        + "({}, {}) is added to invalidated blocks set", chosen, storedBlock);
+    if(blockLog.isDebugEnabled()) {
+      blockLog.debug("BLOCK* chooseExcessRedundancies: "
+          + "({}, {}) is added to invalidated blocks set", chosen, storedBlock);
+    }
   }
 
   private void removeStoredBlock(DatanodeStorageInfo storageInfo, Block block,
@@ -4220,8 +4242,7 @@ private void removeStaleReplicas(List<ReplicaUnderConstruction> staleReplicas,
     for (ReplicaUnderConstruction r : staleReplicas) {
       removeStoredBlock(block,
           r.getExpectedStorageLocation().getDatanodeDescriptor());
-      NameNode.blockStateChangeLog
-          .debug("BLOCK* Removing stale replica {}" + " of {}", r,
+      blockLog.debug("BLOCK* Removing stale replica {} of {}", r,
               Block.toString(r));
     }
   }
@@ -4350,8 +4371,10 @@ private boolean processAndHandleReportedBlock(
           maxNumBlocksToLog, numBlocksLogged);
     }
     for (Block b : toInvalidate) {
-      blockLog.debug("BLOCK* addBlock: block {} on node {} size {} does not " +
-          "belong to any file", b, node, b.getNumBytes());
+      if(blockLog.isDebugEnabled()) {
+        blockLog.debug("BLOCK* addBlock: block {} on node {} size {} does not " +
+            "belong to any file", b, node, b.getNumBytes());
+      }
       addToInvalidates(b, node);
     }
     for (BlockToMarkCorrupt b : toCorrupt) {
@@ -4432,9 +4455,11 @@ private void processIncrementalBlockReport(final DatanodeDescriptor node,
       blockLog.debug("BLOCK* block {}: {} is received from {}",
           rdbi.getStatus(), rdbi.getBlock(), node);
     }
-    blockLog.debug("*BLOCK* NameNode.processIncrementalBlockReport: from "
-            + "{} receiving: {}, received: {}, deleted: {}", node, receiving,
-        received, deleted);
+    if(blockLog.isDebugEnabled()) {
+      blockLog.debug("*BLOCK* NameNode.processIncrementalBlockReport: from "
+              + "{} receiving: {}, received: {}, deleted: {}", node, receiving,
+          received, deleted);
+    }
   }
 
   /**