HDFS-15425. Review Logging of DFSClient. Contributed by Hongbing Wang.

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DFSClient.java

@@ -332,12 +332,9 @@ public class DFSClient implements java.io.Closeable, RemotePeerFactory,
                 MIN_REPLICATION,
             HdfsClientConfigKeys.BlockWrite.ReplaceDatanodeOnFailure.
                 MIN_REPLICATION_DEFAULT);
-    if (LOG.isDebugEnabled()) {
-      LOG.debug(
-          "Sets " + HdfsClientConfigKeys.BlockWrite.ReplaceDatanodeOnFailure.
-              MIN_REPLICATION + " to "
-              + dtpReplaceDatanodeOnFailureReplication);
-    }
+    LOG.debug("Sets {} to {}",
+        HdfsClientConfigKeys.BlockWrite.ReplaceDatanodeOnFailure.
+            MIN_REPLICATION, dtpReplaceDatanodeOnFailureReplication);
     this.ugi = UserGroupInformation.getCurrentUser();
 
     this.namenodeUri = nameNodeUri;

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DFSStripedInputStream.java

@@ -110,9 +110,7 @@ public class DFSStripedInputStream extends DFSInputStream {
         dataBlkNum, parityBlkNum);
     decoder = CodecUtil.createRawDecoder(dfsClient.getConfiguration(),
         ecPolicy.getCodecName(), coderOptions);
-    if (DFSClient.LOG.isDebugEnabled()) {
-      DFSClient.LOG.debug("Creating an striped input stream for file " + src);
-    }
+    DFSClient.LOG.debug("Creating an striped input stream for file {}", src);
   }
 
   private boolean useDirectBuffer() {
@@ -465,10 +463,8 @@ public class DFSStripedInputStream extends DFSInputStream {
         break;
       }
     }
-    if (DFSClient.LOG.isDebugEnabled()) {
-      DFSClient.LOG.debug("refreshLocatedBlock for striped blocks, offset="
-          + block.getStartOffset() + ". Obtained block " + lb + ", idx=" + idx);
-    }
+    DFSClient.LOG.debug("refreshLocatedBlock for striped blocks, offset={}." +
+        " Obtained block {}, idx={}", block.getStartOffset(), lb, idx);
     return StripedBlockUtil.constructInternalBlock(
         lsb, i, cellSize, dataBlkNum, idx);
   }
@@ -526,7 +522,7 @@ public class DFSStripedInputStream extends DFSInputStream {
       if (!warnedNodes.containsAll(dnUUIDs)) {
         DFSClient.LOG.warn(Arrays.toString(nodes) + " are unavailable and " +
             "all striping blocks on them are lost. " +
-            "IgnoredNodes = " + ignoredNodes);
+            "IgnoredNodes = {}", ignoredNodes);
         warnedNodes.addAll(dnUUIDs);
       }
     } else {

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/StripeReader.java

@@ -353,10 +353,8 @@ abstract class StripeReader {
         StripingChunkReadResult r = StripedBlockUtil
             .getNextCompletedStripedRead(service, futures, 0);
         dfsStripedInputStream.updateReadStats(r.getReadStats());
-        if (DFSClient.LOG.isDebugEnabled()) {
-          DFSClient.LOG.debug("Read task returned: " + r + ", for stripe "
-              + alignedStripe);
-        }
+        DFSClient.LOG.debug("Read task returned: {}, for stripe {}",
+            r, alignedStripe);
         StripingChunk returnedChunk = alignedStripe.chunks[r.index];
         Preconditions.checkNotNull(returnedChunk);
         Preconditions.checkState(returnedChunk.state == StripingChunk.PENDING);