HDFS-6923. Propagate LazyPersist flag to DNs via DataTransferProtocol. (Arpit Agarwal)

hadoop-hdfs-project/hadoop-hdfs/CHANGES-HDFS-6581.txt

@@ -7,3 +7,6 @@
     HDFS-6922. Add LazyPersist flag to INodeFile, save it in FsImage and
     edit logs. (Arpit Agarwal)
   
+    HDFS-6923. Propagate LazyPersist flag to DNs via DataTransferProtocol.
+    (Arpit Agarwal)
+

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSOutputStream.java

@@ -344,6 +344,7 @@ public DatanodeInfo load(DatanodeInfo key) throws Exception {
     private long restartDeadline = 0; // Deadline of DN restart
     private BlockConstructionStage stage;  // block construction stage
     private long bytesSent = 0; // number of bytes that've been sent
+    private final boolean isLazyPersistFile;
 
     /** Nodes have been used in the pipeline before and have failed. */
     private final List<DatanodeInfo> failed = new ArrayList<DatanodeInfo>();
@@ -358,8 +359,9 @@ public DatanodeInfo load(DatanodeInfo key) throws Exception {
     /**
      * Default construction for file create
      */
-    private DataStreamer() {
+    private DataStreamer(HdfsFileStatus stat) {
       isAppend = false;
+      isLazyPersistFile = stat.isLazyPersist();
       stage = BlockConstructionStage.PIPELINE_SETUP_CREATE;
     }
     
@@ -377,6 +379,7 @@ private DataStreamer(LocatedBlock lastBlock, HdfsFileStatus stat,
       block = lastBlock.getBlock();
       bytesSent = block.getNumBytes();
       accessToken = lastBlock.getBlockToken();
+      isLazyPersistFile = stat.isLazyPersist();
       long usedInLastBlock = stat.getLen() % blockSize;
       int freeInLastBlock = (int)(blockSize - usedInLastBlock);
 
@@ -1352,7 +1355,7 @@ private boolean createBlockOutputStream(DatanodeInfo[] nodes,
           new Sender(out).writeBlock(blockCopy, nodeStorageTypes[0], accessToken,
               dfsClient.clientName, nodes, nodeStorageTypes, null, bcs, 
               nodes.length, block.getNumBytes(), bytesSent, newGS, checksum,
-              cachingStrategy.get());
+              cachingStrategy.get(), isLazyPersistFile);
   
           // receive ack for connect
           BlockOpResponseProto resp = BlockOpResponseProto.parseFrom(
@@ -1601,7 +1604,7 @@ private DFSOutputStream(DFSClient dfsClient, String src, HdfsFileStatus stat,
     computePacketChunkSize(dfsClient.getConf().writePacketSize,
         checksum.getBytesPerChecksum());
 
-    streamer = new DataStreamer();
+    streamer = new DataStreamer(stat);
     if (favoredNodes != null && favoredNodes.length != 0) {
       streamer.setFavoredNodes(favoredNodes);
     }
@@ -1650,7 +1653,7 @@ private DFSOutputStream(DFSClient dfsClient, String src,
     } else {
       computePacketChunkSize(dfsClient.getConf().writePacketSize,
           checksum.getBytesPerChecksum());
-      streamer = new DataStreamer();
+      streamer = new DataStreamer(stat);
     }
     this.fileEncryptionInfo = stat.getFileEncryptionInfo();
   }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/datatransfer/DataTransferProtocol.java

@@ -106,8 +106,8 @@ public void writeBlock(final ExtendedBlock blk,
       final long maxBytesRcvd,
       final long latestGenerationStamp,
       final DataChecksum requestedChecksum,
-      final CachingStrategy cachingStrategy) throws IOException;
+      final CachingStrategy cachingStrategy,
-
+      final boolean allowLazyPersist) throws IOException;
   /**
    * Transfer a block to another datanode.
    * The block stage must be

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/datatransfer/Receiver.java

@@ -137,7 +137,8 @@ private void opWriteBlock(DataInputStream in) throws IOException {
         fromProto(proto.getRequestedChecksum()),
         (proto.hasCachingStrategy() ?
             getCachingStrategy(proto.getCachingStrategy()) :
-          CachingStrategy.newDefaultStrategy()));
+          CachingStrategy.newDefaultStrategy()),
+        (proto.hasAllowLazyPersist() ? proto.getAllowLazyPersist() : false));
   }
 
   /** Receive {@link Op#TRANSFER_BLOCK} */

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/datatransfer/Sender.java

@@ -124,7 +124,8 @@ public void writeBlock(final ExtendedBlock blk,
       final long maxBytesRcvd,
       final long latestGenerationStamp,
       DataChecksum requestedChecksum,
-      final CachingStrategy cachingStrategy) throws IOException {
+      final CachingStrategy cachingStrategy,
+      final boolean allowLazyPersist) throws IOException {
     ClientOperationHeaderProto header = DataTransferProtoUtil.buildClientHeader(
         blk, clientName, blockToken);
     
@@ -142,7 +143,8 @@ public void writeBlock(final ExtendedBlock blk,
       .setMaxBytesRcvd(maxBytesRcvd)
       .setLatestGenerationStamp(latestGenerationStamp)
       .setRequestedChecksum(checksumProto)
-      .setCachingStrategy(getCachingStrategy(cachingStrategy));
+      .setCachingStrategy(getCachingStrategy(cachingStrategy))
+      .setAllowLazyPersist(allowLazyPersist);
     
     if (source != null) {
       proto.setSource(PBHelper.convertDatanodeInfo(source));

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java

@@ -1809,7 +1809,8 @@ public void run() {
 
         new Sender(out).writeBlock(b, targetStorageTypes[0], accessToken,
             clientname, targets, targetStorageTypes, srcNode,
-            stage, 0, 0, 0, 0, blockSender.getChecksum(), cachingStrategy);
+            stage, 0, 0, 0, 0, blockSender.getChecksum(), cachingStrategy,
+            false);
 
         // send data & checksum
         blockSender.sendBlock(out, unbufOut, null);

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataXceiver.java

@@ -544,7 +544,8 @@ public void writeBlock(final ExtendedBlock block,
       final long maxBytesRcvd,
       final long latestGenerationStamp,
       DataChecksum requestedChecksum,
-      CachingStrategy cachingStrategy) throws IOException {
+      CachingStrategy cachingStrategy,
+      final boolean allowLazyPersist) throws IOException {
     previousOpClientName = clientname;
     updateCurrentThreadName("Receiving block " + block);
     final boolean isDatanode = clientname.length() == 0;
@@ -648,10 +649,11 @@ public void writeBlock(final ExtendedBlock block,
               HdfsConstants.SMALL_BUFFER_SIZE));
           mirrorIn = new DataInputStream(unbufMirrorIn);
 
+          // Do not propagate allowLazyPersist to downstream DataNodes.
           new Sender(mirrorOut).writeBlock(originalBlock, targetStorageTypes[0],
               blockToken, clientname, targets, targetStorageTypes, srcDataNode,
               stage, pipelineSize, minBytesRcvd, maxBytesRcvd,
-              latestGenerationStamp, requestedChecksum, cachingStrategy);
+              latestGenerationStamp, requestedChecksum, cachingStrategy, false);
 
           mirrorOut.flush();
 

hadoop-hdfs-project/hadoop-hdfs/src/main/proto/datatransfer.proto

@@ -109,6 +109,13 @@ message OpWriteBlockProto {
   optional CachingStrategyProto cachingStrategy = 10;
   optional StorageTypeProto storageType = 11 [default = DISK];
   repeated StorageTypeProto targetStorageTypes = 12;
+
+  /**
+   * Hint to the DataNode that the block can be allocated on transient
+   * storage i.e. memory and written to disk lazily. The DataNode is free
+   * to ignore this hint.
+   */
+  optional bool allowLazyPersist = 13 [default = false];
 }
   
 message OpTransferBlockProto {

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDataTransferProtocol.java

@@ -524,6 +524,6 @@ void writeBlock(ExtendedBlock block, BlockConstructionStage stage,
         BlockTokenSecretManager.DUMMY_TOKEN, "cl",
         new DatanodeInfo[1], new StorageType[1], null, stage,
         0, block.getNumBytes(), block.getNumBytes(), newGS,
-        checksum, CachingStrategy.newDefaultStrategy());
+        checksum, CachingStrategy.newDefaultStrategy(), false);
   }
 }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDiskError.java

@@ -152,7 +152,7 @@ public void testReplicationError() throws Exception {
         BlockTokenSecretManager.DUMMY_TOKEN, "",
         new DatanodeInfo[0], new StorageType[0], null,
         BlockConstructionStage.PIPELINE_SETUP_CREATE, 1, 0L, 0L, 0L,
-        checksum, CachingStrategy.newDefaultStrategy());
+        checksum, CachingStrategy.newDefaultStrategy(), false);
     out.flush();
 
     // close the connection before sending the content of the block