HDFS-2562. Refactor DN configuration variables out of DataNode class. Contributed by Todd Lipcon.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1203542 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -14,6 +14,9 @@ Release 0.23.1 - UNRELEASED
 
     HDFS-2543. HADOOP_PREFIX cannot be overridden. (Bruno Mahé via tomwhite)
 
+    HDFS-2562. Refactor DN configuration variables out of DataNode class
+    (todd)
+
   OPTIMIZATIONS
 
     HDFS-2130. Switch default checksum to CRC32C. (todd)

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

@@ -185,8 +185,8 @@ class BlockReceiver implements Closeable {
               " while receiving block " + block + " from " + inAddr);
         }
       }
-      this.dropCacheBehindWrites = datanode.shouldDropCacheBehindWrites();
+      this.dropCacheBehindWrites = datanode.getDnConf().dropCacheBehindWrites;
-      this.syncBehindWrites = datanode.shouldSyncBehindWrites();
+      this.syncBehindWrites = datanode.getDnConf().syncBehindWrites;
       
       final boolean isCreate = isDatanode || isTransfer 
           || stage == BlockConstructionStage.PIPELINE_SETUP_CREATE;
@@ -249,7 +249,7 @@ class BlockReceiver implements Closeable {
     try {
       if (checksumOut != null) {
         checksumOut.flush();
-        if (datanode.syncOnClose && (cout instanceof FileOutputStream)) {
+        if (datanode.getDnConf().syncOnClose && (cout instanceof FileOutputStream)) {
           ((FileOutputStream)cout).getChannel().force(true);
         }
         checksumOut.close();
@@ -265,7 +265,7 @@ class BlockReceiver implements Closeable {
     try {
       if (out != null) {
         out.flush();
-        if (datanode.syncOnClose && (out instanceof FileOutputStream)) {
+        if (datanode.getDnConf().syncOnClose && (out instanceof FileOutputStream)) {
           ((FileOutputStream)out).getChannel().force(true);
         }
         out.close();
@@ -435,7 +435,7 @@ class BlockReceiver implements Closeable {
        * calculation in DFSClient to make the guess accurate.
        */
       int chunkSize = bytesPerChecksum + checksumSize;
-      int chunksPerPacket = (datanode.writePacketSize - PacketHeader.PKT_HEADER_LEN
+      int chunksPerPacket = (datanode.getDnConf().writePacketSize - PacketHeader.PKT_HEADER_LEN
                              + chunkSize - 1)/chunkSize;
       buf = ByteBuffer.allocate(PacketHeader.PKT_HEADER_LEN +
                                 Math.max(chunksPerPacket, 1) * chunkSize);

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

@@ -185,8 +185,8 @@ class BlockSender implements java.io.Closeable {
       this.corruptChecksumOk = corruptChecksumOk;
       this.verifyChecksum = verifyChecksum;
       this.clientTraceFmt = clientTraceFmt;
-      this.readaheadLength = datanode.getReadaheadLength();
+      this.readaheadLength = datanode.getDnConf().readaheadLength;
-      this.shouldDropCacheBehindRead = datanode.shouldDropCacheBehindReads();
+      this.shouldDropCacheBehindRead = datanode.getDnConf().dropCacheBehindReads;
       
       synchronized(datanode.data) { 
         this.replica = getReplica(block, datanode);
@@ -215,7 +215,7 @@ class BlockSender implements java.io.Closeable {
 
       // transferToFully() fails on 32 bit platforms for block sizes >= 2GB,
       // use normal transfer in those cases
-      this.transferToAllowed = datanode.transferToAllowed &&
+      this.transferToAllowed = datanode.getDnConf().transferToAllowed &&
         (!is32Bit || length <= Integer.MAX_VALUE);
 
       DataChecksum csum;

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

@@ -0,0 +1,113 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hdfs.server.datanode;
+
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_BLOCKREPORT_INITIAL_DELAY_DEFAULT;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_BLOCKREPORT_INITIAL_DELAY_KEY;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_BLOCKREPORT_INTERVAL_MSEC_DEFAULT;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_BLOCKREPORT_INTERVAL_MSEC_KEY;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_SOCKET_TIMEOUT_KEY;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_WRITE_PACKET_SIZE_DEFAULT;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_WRITE_PACKET_SIZE_KEY;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_DATANODE_SOCKET_WRITE_TIMEOUT_KEY;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_DATANODE_SYNCONCLOSE_DEFAULT;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_DATANODE_SYNCONCLOSE_KEY;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_DATANODE_TRANSFERTO_ALLOWED_DEFAULT;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_DATANODE_TRANSFERTO_ALLOWED_KEY;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_HEARTBEAT_INTERVAL_DEFAULT;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_HEARTBEAT_INTERVAL_KEY;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hdfs.DFSConfigKeys;
+import org.apache.hadoop.hdfs.server.common.HdfsServerConstants;
+
+/**
+ * Simple class encapsulating all of the configuration that the DataNode
+ * loads at startup time.
+ */
+class DNConf {
+  final int socketTimeout;
+  final int socketWriteTimeout;
+  final int socketKeepaliveTimeout;
+  
+  final boolean transferToAllowed;
+  final boolean dropCacheBehindWrites;
+  final boolean syncBehindWrites;
+  final boolean dropCacheBehindReads;
+  final boolean syncOnClose;
+  
+
+  final long readaheadLength;
+  final long heartBeatInterval;
+  final long blockReportInterval;
+  final long initialBlockReportDelay;
+  final int writePacketSize;
+
+  public DNConf(Configuration conf) {
+    socketTimeout = conf.getInt(DFS_CLIENT_SOCKET_TIMEOUT_KEY,
+        HdfsServerConstants.READ_TIMEOUT);
+    socketWriteTimeout = conf.getInt(DFS_DATANODE_SOCKET_WRITE_TIMEOUT_KEY,
+        HdfsServerConstants.WRITE_TIMEOUT);
+    socketKeepaliveTimeout = conf.getInt(
+        DFSConfigKeys.DFS_DATANODE_SOCKET_REUSE_KEEPALIVE_KEY,
+        DFSConfigKeys.DFS_DATANODE_SOCKET_REUSE_KEEPALIVE_DEFAULT);
+    
+    /* Based on results on different platforms, we might need set the default 
+     * to false on some of them. */
+    transferToAllowed = conf.getBoolean(
+        DFS_DATANODE_TRANSFERTO_ALLOWED_KEY,
+        DFS_DATANODE_TRANSFERTO_ALLOWED_DEFAULT);
+
+    writePacketSize = conf.getInt(DFS_CLIENT_WRITE_PACKET_SIZE_KEY, 
+        DFS_CLIENT_WRITE_PACKET_SIZE_DEFAULT);
+    
+    readaheadLength = conf.getLong(
+        DFSConfigKeys.DFS_DATANODE_READAHEAD_BYTES_KEY,
+        DFSConfigKeys.DFS_DATANODE_READAHEAD_BYTES_DEFAULT);
+    dropCacheBehindWrites = conf.getBoolean(
+        DFSConfigKeys.DFS_DATANODE_DROP_CACHE_BEHIND_WRITES_KEY,
+        DFSConfigKeys.DFS_DATANODE_DROP_CACHE_BEHIND_WRITES_DEFAULT);
+    syncBehindWrites = conf.getBoolean(
+        DFSConfigKeys.DFS_DATANODE_SYNC_BEHIND_WRITES_KEY,
+        DFSConfigKeys.DFS_DATANODE_SYNC_BEHIND_WRITES_DEFAULT);
+    dropCacheBehindReads = conf.getBoolean(
+        DFSConfigKeys.DFS_DATANODE_DROP_CACHE_BEHIND_READS_KEY,
+        DFSConfigKeys.DFS_DATANODE_DROP_CACHE_BEHIND_READS_DEFAULT);
+    
+    this.blockReportInterval = conf.getLong(DFS_BLOCKREPORT_INTERVAL_MSEC_KEY,
+    DFS_BLOCKREPORT_INTERVAL_MSEC_DEFAULT);
+    
+    long initBRDelay = conf.getLong(
+        DFS_BLOCKREPORT_INITIAL_DELAY_KEY,
+        DFS_BLOCKREPORT_INITIAL_DELAY_DEFAULT) * 1000L;
+    if (initBRDelay >= blockReportInterval) {
+      initBRDelay = 0;
+      DataNode.LOG.info("dfs.blockreport.initialDelay is greater than " +
+          "dfs.blockreport.intervalMsec." + " Setting initial delay to 0 msec:");
+    }
+    initialBlockReportDelay = initBRDelay;
+    
+    heartBeatInterval = conf.getLong(DFS_HEARTBEAT_INTERVAL_KEY,
+        DFS_HEARTBEAT_INTERVAL_DEFAULT) * 1000L;
+    
+    // do we need to sync block file contents to disk when blockfile is closed?
+    this.syncOnClose = conf.getBoolean(DFS_DATANODE_SYNCONCLOSE_KEY, 
+        DFS_DATANODE_SYNCONCLOSE_DEFAULT);
+
+  }
+}

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

@@ -19,15 +19,8 @@ package org.apache.hadoop.hdfs.server.datanode;
 
 
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_ADMIN;
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_BLOCKREPORT_INITIAL_DELAY_DEFAULT;
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_BLOCKREPORT_INITIAL_DELAY_KEY;
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_BLOCKREPORT_INTERVAL_MSEC_DEFAULT;
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_BLOCKREPORT_INTERVAL_MSEC_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_HTTPS_NEED_AUTH_DEFAULT;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_HTTPS_NEED_AUTH_KEY;
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_SOCKET_TIMEOUT_KEY;
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_WRITE_PACKET_SIZE_DEFAULT;
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_WRITE_PACKET_SIZE_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_DATANODE_ADDRESS_DEFAULT;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_DATANODE_ADDRESS_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_DATANODE_DATA_DIR_KEY;
@@ -51,17 +44,10 @@ import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_DATANODE_SCAN_PERIOD_HOUR
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_DATANODE_SCAN_PERIOD_HOURS_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_DATANODE_SIMULATEDDATASTORAGE_DEFAULT;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_DATANODE_SIMULATEDDATASTORAGE_KEY;
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_DATANODE_SOCKET_WRITE_TIMEOUT_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_DATANODE_STARTUP_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_DATANODE_STORAGEID_KEY;
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_DATANODE_SYNCONCLOSE_DEFAULT;
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_DATANODE_SYNCONCLOSE_KEY;
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_DATANODE_TRANSFERTO_ALLOWED_DEFAULT;
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_DATANODE_TRANSFERTO_ALLOWED_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_DATANODE_USER_NAME_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_FEDERATION_NAMESERVICES;
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_HEARTBEAT_INTERVAL_DEFAULT;
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_HEARTBEAT_INTERVAL_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_WEBHDFS_ENABLED_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_WEBHDFS_ENABLED_DEFAULT;
 import static org.apache.hadoop.hdfs.server.common.Util.now;
@@ -104,7 +90,6 @@ import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.LocalFileSystem;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.fs.permission.FsPermission;
-import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.DFSUtil;
 import org.apache.hadoop.hdfs.HDFSPolicyProvider;
 import org.apache.hadoop.hdfs.HdfsConfiguration;
@@ -396,9 +381,7 @@ public class DataNode extends Configured
   AtomicInteger xmitsInProgress = new AtomicInteger();
   Daemon dataXceiverServer = null;
   ThreadGroup threadGroup = null;
-  long blockReportInterval;
+  private DNConf dnConf;
-  long initialBlockReportDelay = DFS_BLOCKREPORT_INTERVAL_MSEC_DEFAULT * 1000L;
-  long heartBeatInterval;
   private boolean heartbeatsDisabledForTests = false;
   private DataStorage storage = null;
   private HttpServer infoServer = null;
@@ -408,18 +391,9 @@ public class DataNode extends Configured
   private volatile String hostName; // Host name of this datanode
   
   private static String dnThreadName;
-  int socketTimeout;
-  int socketWriteTimeout = 0;  
-  boolean transferToAllowed = true;
-  private boolean dropCacheBehindWrites = false;
-  private boolean syncBehindWrites = false;
-  private boolean dropCacheBehindReads = false;
-  private long readaheadLength = 0;
 
-  int writePacketSize = 0;
   boolean isBlockTokenEnabled;
   BlockPoolTokenSecretManager blockPoolTokenSecretManager;
-  boolean syncOnClose;
   
   public DataBlockScanner blockScanner = null;
   private DirectoryScanner directoryScanner = null;
@@ -487,49 +461,6 @@ public class DataNode extends Configured
     return name;
   }
 
-  private void initConfig(Configuration conf) {
-    this.socketTimeout =  conf.getInt(DFS_CLIENT_SOCKET_TIMEOUT_KEY,
-                                      HdfsServerConstants.READ_TIMEOUT);
-    this.socketWriteTimeout = conf.getInt(DFS_DATANODE_SOCKET_WRITE_TIMEOUT_KEY,
-                                          HdfsServerConstants.WRITE_TIMEOUT);
-    /* Based on results on different platforms, we might need set the default 
-     * to false on some of them. */
-    this.transferToAllowed = conf.getBoolean(
-        DFS_DATANODE_TRANSFERTO_ALLOWED_KEY,
-        DFS_DATANODE_TRANSFERTO_ALLOWED_DEFAULT);
-    this.writePacketSize = conf.getInt(DFS_CLIENT_WRITE_PACKET_SIZE_KEY, 
-                                       DFS_CLIENT_WRITE_PACKET_SIZE_DEFAULT);
-
-    this.readaheadLength = conf.getLong(
-        DFSConfigKeys.DFS_DATANODE_READAHEAD_BYTES_KEY,
-        DFSConfigKeys.DFS_DATANODE_READAHEAD_BYTES_DEFAULT);
-    this.dropCacheBehindWrites = conf.getBoolean(
-        DFSConfigKeys.DFS_DATANODE_DROP_CACHE_BEHIND_WRITES_KEY,
-        DFSConfigKeys.DFS_DATANODE_DROP_CACHE_BEHIND_WRITES_DEFAULT);
-    this.syncBehindWrites = conf.getBoolean(
-        DFSConfigKeys.DFS_DATANODE_SYNC_BEHIND_WRITES_KEY,
-        DFSConfigKeys.DFS_DATANODE_SYNC_BEHIND_WRITES_DEFAULT);
-    this.dropCacheBehindReads = conf.getBoolean(
-        DFSConfigKeys.DFS_DATANODE_DROP_CACHE_BEHIND_READS_KEY,
-        DFSConfigKeys.DFS_DATANODE_DROP_CACHE_BEHIND_READS_DEFAULT);
-
-    this.blockReportInterval = conf.getLong(DFS_BLOCKREPORT_INTERVAL_MSEC_KEY,
-        DFS_BLOCKREPORT_INTERVAL_MSEC_DEFAULT);
-    this.initialBlockReportDelay = conf.getLong(
-        DFS_BLOCKREPORT_INITIAL_DELAY_KEY,
-        DFS_BLOCKREPORT_INITIAL_DELAY_DEFAULT) * 1000L;
-    if (this.initialBlockReportDelay >= blockReportInterval) {
-      this.initialBlockReportDelay = 0;
-      LOG.info("dfs.blockreport.initialDelay is greater than " +
-        "dfs.blockreport.intervalMsec." + " Setting initial delay to 0 msec:");
-    }
-    this.heartBeatInterval = conf.getLong(DFS_HEARTBEAT_INTERVAL_KEY,
-        DFS_HEARTBEAT_INTERVAL_DEFAULT) * 1000L;
-
-    // do we need to sync block file contents to disk when blockfile is closed?
-    this.syncOnClose = conf.getBoolean(DFS_DATANODE_SYNCONCLOSE_KEY, 
-                                       DFS_DATANODE_SYNCONCLOSE_DEFAULT);
-  }
   
   private void startInfoServer(Configuration conf) throws IOException {
     // create a servlet to serve full-file content
@@ -688,7 +619,7 @@ public class DataNode extends Configured
     // find free port or use privileged port provided
     ServerSocket ss;
     if(secureResources == null) {
-      ss = (socketWriteTimeout > 0) ? 
+      ss = (dnConf.socketWriteTimeout > 0) ? 
           ServerSocketChannel.open().socket() : new ServerSocket();
           Server.bind(ss, socAddr, 0);
     } else {
@@ -760,11 +691,13 @@ public class DataNode extends Configured
     private volatile boolean shouldServiceRun = true;
     UpgradeManagerDatanode upgradeManager = null;
     private final DataNode dn;
+    private final DNConf dnConf;
 
     BPOfferService(InetSocketAddress nnAddr, DataNode dn) {
       this.dn = dn;
       this.bpRegistration = dn.createRegistration();
       this.nnAddr = nnAddr;
+      this.dnConf = dn.getDnConf();
     }
 
     /**
@@ -866,9 +799,9 @@ public class DataNode extends Configured
     void scheduleBlockReport(long delay) {
       if (delay > 0) { // send BR after random delay
         lastBlockReport = System.currentTimeMillis()
-        - ( dn.blockReportInterval - DFSUtil.getRandom().nextInt((int)(delay)));
+        - ( dnConf.blockReportInterval - DFSUtil.getRandom().nextInt((int)(delay)));
       } else { // send at next heartbeat
-        lastBlockReport = lastHeartbeat - dn.blockReportInterval;
+        lastBlockReport = lastHeartbeat - dnConf.blockReportInterval;
       }
       resetBlockReportTime = true; // reset future BRs for randomness
     }
@@ -965,7 +898,7 @@ public class DataNode extends Configured
       // send block report if timer has expired.
       DatanodeCommand cmd = null;
       long startTime = now();
-      if (startTime - lastBlockReport > dn.blockReportInterval) {
+      if (startTime - lastBlockReport > dnConf.blockReportInterval) {
 
         // Create block report
         long brCreateStartTime = now();
@@ -987,7 +920,7 @@ public class DataNode extends Configured
         // If we have sent the first block report, then wait a random
         // time before we start the periodic block reports.
         if (resetBlockReportTime) {
-          lastBlockReport = startTime - DFSUtil.getRandom().nextInt((int)(dn.blockReportInterval));
+          lastBlockReport = startTime - DFSUtil.getRandom().nextInt((int)(dnConf.blockReportInterval));
           resetBlockReportTime = false;
         } else {
           /* say the last block report was at 8:20:14. The current report
@@ -997,7 +930,7 @@ public class DataNode extends Configured
            *   2) unexpected like 11:35:43, next report should be at 12:20:14
            */
           lastBlockReport += (now() - lastBlockReport) /
-          dn.blockReportInterval * dn.blockReportInterval;
+          dnConf.blockReportInterval * dnConf.blockReportInterval;
         }
         LOG.info("sent block report, processed command:" + cmd);
       }
@@ -1059,9 +992,9 @@ public class DataNode extends Configured
      */
     private void offerService() throws Exception {
       LOG.info("For namenode " + nnAddr + " using BLOCKREPORT_INTERVAL of "
-          + dn.blockReportInterval + "msec" + " Initial delay: "
+          + dnConf.blockReportInterval + "msec" + " Initial delay: "
-          + dn.initialBlockReportDelay + "msec" + "; heartBeatInterval="
+          + dnConf.initialBlockReportDelay + "msec" + "; heartBeatInterval="
-          + dn.heartBeatInterval);
+          + dnConf.heartBeatInterval);
 
       //
       // Now loop for a long time....
@@ -1073,7 +1006,7 @@ public class DataNode extends Configured
           //
           // Every so often, send heartbeat or block-report
           //
-          if (startTime - lastHeartbeat > dn.heartBeatInterval) {
+          if (startTime - lastHeartbeat > dnConf.heartBeatInterval) {
             //
             // All heartbeat messages include following info:
             // -- Datanode name
@@ -1111,7 +1044,7 @@ public class DataNode extends Configured
           // There is no work to do;  sleep until hearbeat timer elapses, 
           // or work arrives, and then iterate again.
           //
-          long waitTime = dn.heartBeatInterval - 
+          long waitTime = dnConf.heartBeatInterval - 
           (System.currentTimeMillis() - lastHeartbeat);
           synchronized(receivedBlockList) {
             if (waitTime > 0 && receivedBlockList.size() == 0) {
@@ -1134,7 +1067,7 @@ public class DataNode extends Configured
           }
           LOG.warn("RemoteException in offerService", re);
           try {
-            long sleepTime = Math.min(1000, dn.heartBeatInterval);
+            long sleepTime = Math.min(1000, dnConf.heartBeatInterval);
             Thread.sleep(sleepTime);
           } catch (InterruptedException ie) {
             Thread.currentThread().interrupt();
@@ -1202,7 +1135,7 @@ public class DataNode extends Configured
       LOG.info("in register:" + ";bpDNR="+bpRegistration.storageInfo);
 
       // random short delay - helps scatter the BR from all DNs
-      scheduleBlockReport(dn.initialBlockReportDelay);
+      scheduleBlockReport(dnConf.initialBlockReportDelay);
     }
 
 
@@ -1412,11 +1345,11 @@ public class DataNode extends Configured
     this.secureResources = resources;
     this.dataDirs = dataDirs;
     this.conf = conf;
+    this.dnConf = new DNConf(conf);
 
     storage = new DataStorage();
     
     // global DN settings
-    initConfig(conf);
     registerMXBean();
     initDataXceiver(conf);
     startInfoServer(conf);
@@ -1664,7 +1597,7 @@ public class DataNode extends Configured
    * Creates either NIO or regular depending on socketWriteTimeout.
    */
   protected Socket newSocket() throws IOException {
-    return (socketWriteTimeout > 0) ? 
+    return (dnConf.socketWriteTimeout > 0) ? 
            SocketChannel.open().socket() : new Socket();                                   
   }
 
@@ -2091,10 +2024,10 @@ public class DataNode extends Configured
         InetSocketAddress curTarget = 
           NetUtils.createSocketAddr(targets[0].getName());
         sock = newSocket();
-        NetUtils.connect(sock, curTarget, socketTimeout);
+        NetUtils.connect(sock, curTarget, dnConf.socketTimeout);
-        sock.setSoTimeout(targets.length * socketTimeout);
+        sock.setSoTimeout(targets.length * dnConf.socketTimeout);
 
-        long writeTimeout = socketWriteTimeout + 
+        long writeTimeout = dnConf.socketWriteTimeout + 
                             HdfsServerConstants.WRITE_TIMEOUT_EXTENSION * (targets.length-1);
         OutputStream baseStream = NetUtils.getOutputStream(sock, writeTimeout);
         out = new DataOutputStream(new BufferedOutputStream(baseStream,
@@ -2537,7 +2470,7 @@ public class DataNode extends Configured
         DatanodeRegistration bpReg = bpos.bpRegistration;
         InterDatanodeProtocol datanode = bpReg.equals(id)?
             this: DataNode.createInterDataNodeProtocolProxy(id, getConf(),
-                socketTimeout);
+                dnConf.socketTimeout);
         ReplicaRecoveryInfo info = callInitReplicaRecovery(datanode, rBlock);
         if (info != null &&
             info.getGenerationStamp() >= block.getGenerationStamp() &&
@@ -2926,20 +2859,8 @@ public class DataNode extends Configured
                        (DataXceiverServer) this.dataXceiverServer.getRunnable();
     return dxcs.balanceThrottler.getBandwidth();
   }
-
-  long getReadaheadLength() {
-    return readaheadLength;
-  }
-
-  boolean shouldDropCacheBehindWrites() {
-    return dropCacheBehindWrites;
-  }
-
-  boolean shouldDropCacheBehindReads() {
-    return dropCacheBehindReads;
-  }
   
-  boolean shouldSyncBehindWrites() {
+  DNConf getDnConf() {
-    return syncBehindWrites;
+    return dnConf;
   }
 }

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

@@ -38,7 +38,6 @@ import java.nio.channels.ClosedChannelException;
 import java.util.Arrays;
 
 import org.apache.commons.logging.Log;
-import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
 import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants;
@@ -82,9 +81,9 @@ class DataXceiver extends Receiver implements Runnable {
   private final String remoteAddress; // address of remote side
   private final String localAddress;  // local address of this daemon
   private final DataNode datanode;
+  private final DNConf dnConf;
   private final DataXceiverServer dataXceiverServer;
 
-  private int socketKeepaliveTimeout;
   private long opStartTime; //the start time of receiving an Op
   
   public DataXceiver(Socket s, DataNode datanode, 
@@ -95,14 +94,11 @@ class DataXceiver extends Receiver implements Runnable {
     this.s = s;
     this.isLocal = s.getInetAddress().equals(s.getLocalAddress());
     this.datanode = datanode;
+    this.dnConf = datanode.getDnConf();
     this.dataXceiverServer = dataXceiverServer;
     remoteAddress = s.getRemoteSocketAddress().toString();
     localAddress = s.getLocalSocketAddress().toString();
 
-    socketKeepaliveTimeout = datanode.getConf().getInt(
-        DFSConfigKeys.DFS_DATANODE_SOCKET_REUSE_KEEPALIVE_KEY,
-        DFSConfigKeys.DFS_DATANODE_SOCKET_REUSE_KEEPALIVE_DEFAULT);
-
     if (LOG.isDebugEnabled()) {
       LOG.debug("Number of active connections is: "
           + datanode.getXceiverCount());
@@ -144,8 +140,8 @@ class DataXceiver extends Receiver implements Runnable {
 
         try {
           if (opsProcessed != 0) {
-            assert socketKeepaliveTimeout > 0;
+            assert dnConf.socketKeepaliveTimeout > 0;
-            s.setSoTimeout(socketKeepaliveTimeout);
+            s.setSoTimeout(dnConf.socketKeepaliveTimeout);
           }
           op = readOp();
         } catch (InterruptedIOException ignored) {
@@ -180,7 +176,7 @@ class DataXceiver extends Receiver implements Runnable {
         opStartTime = now();
         processOp(op);
         ++opsProcessed;
-      } while (!s.isClosed() && socketKeepaliveTimeout > 0);
+      } while (!s.isClosed() && dnConf.socketKeepaliveTimeout > 0);
     } catch (Throwable t) {
       LOG.error(datanode.getMachineName() + ":DataXceiver error processing " +
                 ((op == null) ? "unknown" : op.name()) + " operation " +
@@ -205,7 +201,7 @@ class DataXceiver extends Receiver implements Runnable {
       final long blockOffset,
       final long length) throws IOException {
     OutputStream baseStream = NetUtils.getOutputStream(s, 
-        datanode.socketWriteTimeout);
+        dnConf.socketWriteTimeout);
     DataOutputStream out = new DataOutputStream(new BufferedOutputStream(
         baseStream, HdfsConstants.SMALL_BUFFER_SIZE));
     checkAccess(out, true, block, blockToken,
@@ -231,13 +227,13 @@ class DataXceiver extends Receiver implements Runnable {
       } catch(IOException e) {
         String msg = "opReadBlock " + block + " received exception " + e; 
         LOG.info(msg);
-        sendResponse(s, ERROR, msg, datanode.socketWriteTimeout);
+        sendResponse(s, ERROR, msg, dnConf.socketWriteTimeout);
         throw e;
       }
       
       // send op status
       writeSuccessWithChecksumInfo(blockSender,
-          getStreamWithTimeout(s, datanode.socketWriteTimeout));
+          getStreamWithTimeout(s, dnConf.socketWriteTimeout));
 
       long read = blockSender.sendBlock(out, baseStream, null); // send data
 
@@ -335,7 +331,7 @@ class DataXceiver extends Receiver implements Runnable {
     // reply to upstream datanode or client 
     final DataOutputStream replyOut = new DataOutputStream(
         new BufferedOutputStream(
-            NetUtils.getOutputStream(s, datanode.socketWriteTimeout),
+            NetUtils.getOutputStream(s, dnConf.socketWriteTimeout),
             HdfsConstants.SMALL_BUFFER_SIZE));
     checkAccess(replyOut, isClient, block, blockToken,
         Op.WRITE_BLOCK, BlockTokenSecretManager.AccessMode.WRITE);
@@ -370,9 +366,9 @@ class DataXceiver extends Receiver implements Runnable {
         mirrorTarget = NetUtils.createSocketAddr(mirrorNode);
         mirrorSock = datanode.newSocket();
         try {
-          int timeoutValue = datanode.socketTimeout
+          int timeoutValue = dnConf.socketTimeout
               + (HdfsServerConstants.READ_TIMEOUT_EXTENSION * targets.length);
-          int writeTimeout = datanode.socketWriteTimeout + 
+          int writeTimeout = dnConf.socketWriteTimeout + 
                       (HdfsServerConstants.WRITE_TIMEOUT_EXTENSION * targets.length);
           NetUtils.connect(mirrorSock, mirrorTarget, timeoutValue);
           mirrorSock.setSoTimeout(timeoutValue);
@@ -508,7 +504,7 @@ class DataXceiver extends Receiver implements Runnable {
     updateCurrentThreadName(Op.TRANSFER_BLOCK + " " + blk);
 
     final DataOutputStream out = new DataOutputStream(
-        NetUtils.getOutputStream(s, datanode.socketWriteTimeout));
+        NetUtils.getOutputStream(s, dnConf.socketWriteTimeout));
     try {
       datanode.transferReplicaForPipelineRecovery(blk, targets, clientName);
       writeResponse(Status.SUCCESS, null, out);
@@ -521,7 +517,7 @@ class DataXceiver extends Receiver implements Runnable {
   public void blockChecksum(final ExtendedBlock block,
       final Token<BlockTokenIdentifier> blockToken) throws IOException {
     final DataOutputStream out = new DataOutputStream(
-        NetUtils.getOutputStream(s, datanode.socketWriteTimeout));
+        NetUtils.getOutputStream(s, dnConf.socketWriteTimeout));
     checkAccess(out, true, block, blockToken,
         Op.BLOCK_CHECKSUM, BlockTokenSecretManager.AccessMode.READ);
     updateCurrentThreadName("Reading metadata for block " + block);
@@ -581,7 +577,7 @@ class DataXceiver extends Receiver implements Runnable {
         LOG.warn("Invalid access token in request from " + remoteAddress
             + " for OP_COPY_BLOCK for block " + block + " : "
             + e.getLocalizedMessage());
-        sendResponse(s, ERROR_ACCESS_TOKEN, "Invalid access token", datanode.socketWriteTimeout);
+        sendResponse(s, ERROR_ACCESS_TOKEN, "Invalid access token", dnConf.socketWriteTimeout);
         return;
       }
 
@@ -591,7 +587,7 @@ class DataXceiver extends Receiver implements Runnable {
       String msg = "Not able to copy block " + block.getBlockId() + " to " 
       + s.getRemoteSocketAddress() + " because threads quota is exceeded."; 
       LOG.info(msg);
-      sendResponse(s, ERROR, msg, datanode.socketWriteTimeout);
+      sendResponse(s, ERROR, msg, dnConf.socketWriteTimeout);
       return;
     }
 
@@ -606,7 +602,7 @@ class DataXceiver extends Receiver implements Runnable {
 
       // set up response stream
       OutputStream baseStream = NetUtils.getOutputStream(
-          s, datanode.socketWriteTimeout);
+          s, dnConf.socketWriteTimeout);
       reply = new DataOutputStream(new BufferedOutputStream(
           baseStream, HdfsConstants.SMALL_BUFFER_SIZE));
 
@@ -659,7 +655,7 @@ class DataXceiver extends Receiver implements Runnable {
             + " for OP_REPLACE_BLOCK for block " + block + " : "
             + e.getLocalizedMessage());
         sendResponse(s, ERROR_ACCESS_TOKEN, "Invalid access token",
-            datanode.socketWriteTimeout);
+            dnConf.socketWriteTimeout);
         return;
       }
     }
@@ -668,7 +664,7 @@ class DataXceiver extends Receiver implements Runnable {
       String msg = "Not able to receive block " + block.getBlockId() + " from " 
           + s.getRemoteSocketAddress() + " because threads quota is exceeded."; 
       LOG.warn(msg);
-      sendResponse(s, ERROR, msg, datanode.socketWriteTimeout);
+      sendResponse(s, ERROR, msg, dnConf.socketWriteTimeout);
       return;
     }
 
@@ -684,11 +680,11 @@ class DataXceiver extends Receiver implements Runnable {
       InetSocketAddress proxyAddr = NetUtils.createSocketAddr(
           proxySource.getName());
       proxySock = datanode.newSocket();
-      NetUtils.connect(proxySock, proxyAddr, datanode.socketTimeout);
+      NetUtils.connect(proxySock, proxyAddr, dnConf.socketTimeout);
-      proxySock.setSoTimeout(datanode.socketTimeout);
+      proxySock.setSoTimeout(dnConf.socketTimeout);
 
       OutputStream baseStream = NetUtils.getOutputStream(proxySock, 
-          datanode.socketWriteTimeout);
+          dnConf.socketWriteTimeout);
       proxyOut = new DataOutputStream(new BufferedOutputStream(baseStream,
           HdfsConstants.SMALL_BUFFER_SIZE));
 
@@ -750,7 +746,7 @@ class DataXceiver extends Receiver implements Runnable {
       
       // send response back
       try {
-        sendResponse(s, opStatus, errMsg, datanode.socketWriteTimeout);
+        sendResponse(s, opStatus, errMsg, dnConf.socketWriteTimeout);
       } catch (IOException ioe) {
         LOG.warn("Error writing reply back to " + s.getRemoteSocketAddress());
       }
@@ -826,7 +822,7 @@ class DataXceiver extends Receiver implements Runnable {
           if (reply) {
             if (out == null) {
               out = new DataOutputStream(
-                  NetUtils.getOutputStream(s, datanode.socketWriteTimeout));
+                  NetUtils.getOutputStream(s, dnConf.socketWriteTimeout));
             }
             
             BlockOpResponseProto.Builder resp = BlockOpResponseProto.newBuilder()

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

@@ -154,7 +154,7 @@ public class TestInterDatanodeProtocol {
       //connect to a data node
       DataNode datanode = cluster.getDataNode(datanodeinfo[0].getIpcPort());
       InterDatanodeProtocol idp = DataNode.createInterDataNodeProtocolProxy(
-          datanodeinfo[0], conf, datanode.socketTimeout);
+          datanodeinfo[0], conf, datanode.getDnConf().socketTimeout);
       assertTrue(datanode != null);
       
       //stop block scanner, so we could compare lastScanTime