HDFS-5891. webhdfs should not try connecting the DN during redirection. Contributed by Haohui Mai

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1567810 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -425,6 +425,9 @@ Release 2.4.0 - UNRELEASED
     HDFS-5938. Make BlockReaderFactory#BlockReaderPeer a static class to avoid
     a findbugs warning. (cmccabe)
 
+    HDFS-5891. webhdfs should not try connecting the DN during redirection
+    (Haohui Mai via brandonli)
+
 Release 2.3.1 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/common/JspHelper.java

@@ -18,7 +18,26 @@
 
 package org.apache.hadoop.hdfs.server.common;
 
-import com.google.common.base.Charsets;
+import static org.apache.hadoop.fs.CommonConfigurationKeys.DEFAULT_HADOOP_HTTP_STATIC_USER;
+import static org.apache.hadoop.fs.CommonConfigurationKeys.HADOOP_HTTP_STATIC_USER;
+
+import java.io.ByteArrayInputStream;
+import java.io.DataInputStream;
+import java.io.IOException;
+import java.io.UnsupportedEncodingException;
+import java.net.InetSocketAddress;
+import java.net.Socket;
+import java.net.URL;
+import java.net.URLEncoder;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.HashMap;
+import java.util.List;
+
+import javax.servlet.ServletContext;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.jsp.JspWriter;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -33,7 +52,11 @@ import org.apache.hadoop.hdfs.DFSUtil;
 import org.apache.hadoop.hdfs.RemotePeerFactory;
 import org.apache.hadoop.hdfs.net.Peer;
 import org.apache.hadoop.hdfs.net.TcpPeerServer;
-import org.apache.hadoop.hdfs.protocol.*;
+import org.apache.hadoop.hdfs.protocol.DatanodeID;
+import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
+import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
+import org.apache.hadoop.hdfs.protocol.LocatedBlock;
+import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
 import org.apache.hadoop.hdfs.security.token.block.BlockTokenIdentifier;
 import org.apache.hadoop.hdfs.security.token.block.DataEncryptionKey;
 import org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenIdentifier;
@@ -56,22 +79,7 @@ import org.apache.hadoop.security.authorize.ProxyUsers;
 import org.apache.hadoop.security.token.Token;
 import org.apache.hadoop.util.VersionInfo;
 
-import javax.servlet.ServletContext;
-import javax.servlet.http.HttpServletRequest;
-import javax.servlet.jsp.JspWriter;
-
-import java.io.ByteArrayInputStream;
-import java.io.DataInputStream;
-import java.io.IOException;
-import java.io.UnsupportedEncodingException;
-import java.net.InetSocketAddress;
-import java.net.Socket;
-import java.net.URL;
-import java.net.URLEncoder;
-import java.util.*;
-
-import static org.apache.hadoop.fs.CommonConfigurationKeys.DEFAULT_HADOOP_HTTP_STATIC_USER;
-import static org.apache.hadoop.fs.CommonConfigurationKeys.HADOOP_HTTP_STATIC_USER;
+import com.google.common.base.Charsets;
 
 @InterfaceAudience.Private
 public class JspHelper {
@@ -171,58 +179,31 @@ public class JspHelper {
     }
     NodeRecord[] nodes = map.values().toArray(new NodeRecord[map.size()]);
     Arrays.sort(nodes, new NodeRecordComparator());
-    return bestNode(nodes, false, conf);
+    return bestNode(nodes, false);
   }
 
   public static DatanodeInfo bestNode(LocatedBlock blk, Configuration conf)
       throws IOException {
     DatanodeInfo[] nodes = blk.getLocations();
-    return bestNode(nodes, true, conf);
+    return bestNode(nodes, true);
   }
 
-  public static DatanodeInfo bestNode(DatanodeInfo[] nodes, boolean doRandom,
-      Configuration conf) throws IOException {
-    TreeSet<DatanodeInfo> deadNodes = new TreeSet<DatanodeInfo>();
-    DatanodeInfo chosenNode = null;
-    int failures = 0;
-    Socket s = null;
-    int index = -1;
+  private static DatanodeInfo bestNode(DatanodeInfo[] nodes, boolean doRandom)
+      throws IOException {
     if (nodes == null || nodes.length == 0) {
       throw new IOException("No nodes contain this block");
     }
-    while (s == null) {
-      if (chosenNode == null) {
-        do {
-          if (doRandom) {
-            index = DFSUtil.getRandom().nextInt(nodes.length);
-          } else {
-            index++;
-          }
-          chosenNode = nodes[index];
-        } while (deadNodes.contains(chosenNode));
-      }
-      chosenNode = nodes[index];
+    int l = 0;
+    while (l < nodes.length && !nodes[l].isDecommissioned()) {
+      ++l;
+    }
 
-      //just ping to check whether the node is alive
-      InetSocketAddress targetAddr = NetUtils.createSocketAddr(
-          chosenNode.getInfoAddr());
-        
-      try {
-        s = NetUtils.getDefaultSocketFactory(conf).createSocket();
-        s.connect(targetAddr, HdfsServerConstants.READ_TIMEOUT);
-        s.setSoTimeout(HdfsServerConstants.READ_TIMEOUT);
-      } catch (IOException e) {
-        deadNodes.add(chosenNode);
-        IOUtils.closeSocket(s);
-        s = null;
-        failures++;
-      }
-      if (failures == nodes.length)
-        throw new IOException("Could not reach the block containing the data. Please try again");
-        
+    if (l == 0) {
+      throw new IOException("No active nodes contain this block");
     }
-    s.close();
-    return chosenNode;
+
+    int index = doRandom ? DFSUtil.getRandom().nextInt(l) : 0;
+    return nodes[index];
   }
 
   public static void streamBlockInAscii(InetSocketAddress addr, String poolId,

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/web/resources/NamenodeWebHdfsMethods.java

@@ -107,6 +107,7 @@ import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.security.token.Token;
 import org.apache.hadoop.security.token.TokenIdentifier;
 
+import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Charsets;
 import com.sun.jersey.spi.container.ResourceFilters;
 
@@ -160,9 +161,10 @@ public class NamenodeWebHdfsMethods {
     response.setContentType(null);
   }
 
+  @VisibleForTesting
   static DatanodeInfo chooseDatanode(final NameNode namenode,
       final String path, final HttpOpParam.Op op, final long openOffset,
-      final long blocksize, final Configuration conf) throws IOException {
+      final long blocksize) throws IOException {
     final BlockManager bm = namenode.getNamesystem().getBlockManager();
 
     if (op == PutOpParam.Op.CREATE) {
@@ -201,7 +203,7 @@ public class NamenodeWebHdfsMethods {
         final LocatedBlocks locations = np.getBlockLocations(path, offset, 1);
         final int count = locations.locatedBlockCount();
         if (count > 0) {
-          return JspHelper.bestNode(locations.get(0).getLocations(), false, conf);
+          return bestNode(locations.get(0).getLocations());
         }
       }
     } 
@@ -210,13 +212,26 @@ public class NamenodeWebHdfsMethods {
         ).chooseRandom(NodeBase.ROOT);
   }
 
+  /**
+   * Choose the datanode to redirect the request. Note that the nodes have been
+   * sorted based on availability and network distances, thus it is sufficient
+   * to return the first element of the node here.
+   */
+  private static DatanodeInfo bestNode(DatanodeInfo[] nodes) throws IOException {
+    if (nodes.length == 0 || nodes[0].isDecommissioned()) {
+      throw new IOException("No active nodes contain this block");
+    }
+    return nodes[0];
+  }
+
   private Token<? extends TokenIdentifier> generateDelegationToken(
       final NameNode namenode, final UserGroupInformation ugi,
       final String renewer) throws IOException {
     final Credentials c = DelegationTokenSecretManager.createCredentials(
         namenode, ugi, renewer != null? renewer: ugi.getShortUserName());
     final Token<? extends TokenIdentifier> t = c.getAllTokens().iterator().next();
-    Text kind = request.getScheme().equals("http") ? WebHdfsFileSystem.TOKEN_KIND : SWebHdfsFileSystem.TOKEN_KIND;
+    Text kind = request.getScheme().equals("http") ? WebHdfsFileSystem.TOKEN_KIND
+        : SWebHdfsFileSystem.TOKEN_KIND;
     t.setKind(kind);
     return t;
   }
@@ -227,9 +242,8 @@ public class NamenodeWebHdfsMethods {
       final String path, final HttpOpParam.Op op, final long openOffset,
       final long blocksize,
       final Param<?, ?>... parameters) throws URISyntaxException, IOException {
-    final Configuration conf = (Configuration)context.getAttribute(JspHelper.CURRENT_CONF);
     final DatanodeInfo dn = chooseDatanode(namenode, path, op, openOffset,
-        blocksize, conf);
+        blocksize);
 
     final String delegationQuery;
     if (!UserGroupInformation.isSecurityEnabled()) {

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/web/resources/TestWebHdfsDataLocality.java

@@ -92,7 +92,7 @@ public class TestWebHdfsDataLocality {
 
           //The chosen datanode must be the same as the client address
           final DatanodeInfo chosen = NamenodeWebHdfsMethods.chooseDatanode(
-              namenode, f, PutOpParam.Op.CREATE, -1L, blocksize, conf);
+              namenode, f, PutOpParam.Op.CREATE, -1L, blocksize);
           Assert.assertEquals(ipAddr, chosen.getIpAddr());
         }
       }
@@ -117,19 +117,19 @@ public class TestWebHdfsDataLocality {
 
       { //test GETFILECHECKSUM
         final DatanodeInfo chosen = NamenodeWebHdfsMethods.chooseDatanode(
-            namenode, f, GetOpParam.Op.GETFILECHECKSUM, -1L, blocksize, conf);
+            namenode, f, GetOpParam.Op.GETFILECHECKSUM, -1L, blocksize);
         Assert.assertEquals(expected, chosen);
       }
   
       { //test OPEN
         final DatanodeInfo chosen = NamenodeWebHdfsMethods.chooseDatanode(
-            namenode, f, GetOpParam.Op.OPEN, 0, blocksize, conf);
+            namenode, f, GetOpParam.Op.OPEN, 0, blocksize);
         Assert.assertEquals(expected, chosen);
       }
 
       { //test APPEND
         final DatanodeInfo chosen = NamenodeWebHdfsMethods.chooseDatanode(
-            namenode, f, PostOpParam.Op.APPEND, -1L, blocksize, conf);
+            namenode, f, PostOpParam.Op.APPEND, -1L, blocksize);
         Assert.assertEquals(expected, chosen);
       }
     } finally {

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/web/TestHttpsFileSystem.java

@@ -18,6 +18,7 @@
 package org.apache.hadoop.hdfs.web;
 
 import java.io.File;
+import java.io.InputStream;
 import java.net.InetSocketAddress;
 import java.net.URI;
 
@@ -92,6 +93,9 @@ public class TestHttpsFileSystem {
     os.write(23);
     os.close();
     Assert.assertTrue(fs.exists(f));
+    InputStream is = fs.open(f);
+    Assert.assertEquals(23, is.read());
+    is.close();
     fs.close();
   }
 }