/**
  * Parse a list of strings into longs.
  *
  * @param strs the list of strings to parse
  * @return a list of longs that were parsed. same length as strs.
  */
 private static long[] parseTimestamps(String[] strs) {
   if (strs == null) {
     return null;
   }
   long[] result = new long[strs.length];
   for (int i = 0; i < strs.length; ++i) {
     result[i] = Long.parseLong(strs[i]);
   }
   return result;
 }
  @Override
  public void map(LongWritable key, Text value, Context context)
      throws IOException, InterruptedException {
    String line = value.toString();
    String[] tokens = line.split("\\s");
    String hour = new String();
    long numRequests = 0;

    if (tokens.length > 4) {
      // get the project name field
      hour = tokens[4];

      // get the number of requests field
      numRequests = Long.parseLong(tokens[2]);

      // output the key, value pairs where the key is a combination of
      // project name and datetime and the value is number of requests
      context.write(new Text(hour), new LongWritable(numRequests));
    }
  }
Example #3
0
  @Override
  public final void run() {
    try {

      // before preparing the job localize
      // all the archives
      TaskAttemptID taskid = t.getTaskID();
      LocalDirAllocator lDirAlloc = new LocalDirAllocator("mapred.local.dir");
      File jobCacheDir = null;
      if (conf.getJar() != null) {
        jobCacheDir = new File(new Path(conf.getJar()).getParent().toString());
      }
      File workDir =
          new File(
              lDirAlloc
                  .getLocalPathToRead(
                      TaskTracker.getJobCacheSubdir()
                          + Path.SEPARATOR
                          + t.getJobID()
                          + Path.SEPARATOR
                          + t.getTaskID()
                          + Path.SEPARATOR
                          + MRConstants.WORKDIR,
                      conf)
                  .toString());

      URI[] archives = DistributedCache.getCacheArchives(conf);
      URI[] files = DistributedCache.getCacheFiles(conf);
      FileStatus fileStatus;
      FileSystem fileSystem;
      Path localPath;
      String baseDir;

      if ((archives != null) || (files != null)) {
        if (archives != null) {
          String[] archivesTimestamps = DistributedCache.getArchiveTimestamps(conf);
          Path[] p = new Path[archives.length];
          for (int i = 0; i < archives.length; i++) {
            fileSystem = FileSystem.get(archives[i], conf);
            fileStatus = fileSystem.getFileStatus(new Path(archives[i].getPath()));
            String cacheId = DistributedCache.makeRelative(archives[i], conf);
            String cachePath = TaskTracker.getCacheSubdir() + Path.SEPARATOR + cacheId;
            if (lDirAlloc.ifExists(cachePath, conf)) {
              localPath = lDirAlloc.getLocalPathToRead(cachePath, conf);
            } else {
              localPath = lDirAlloc.getLocalPathForWrite(cachePath, fileStatus.getLen(), conf);
            }
            baseDir = localPath.toString().replace(cacheId, "");
            p[i] =
                DistributedCache.getLocalCache(
                    archives[i],
                    conf,
                    new Path(baseDir),
                    fileStatus,
                    true,
                    Long.parseLong(archivesTimestamps[i]),
                    new Path(workDir.getAbsolutePath()),
                    false);
          }
          DistributedCache.setLocalArchives(conf, stringifyPathArray(p));
        }
        if ((files != null)) {
          String[] fileTimestamps = DistributedCache.getFileTimestamps(conf);
          Path[] p = new Path[files.length];
          for (int i = 0; i < files.length; i++) {
            fileSystem = FileSystem.get(files[i], conf);
            fileStatus = fileSystem.getFileStatus(new Path(files[i].getPath()));
            String cacheId = DistributedCache.makeRelative(files[i], conf);
            String cachePath = TaskTracker.getCacheSubdir() + Path.SEPARATOR + cacheId;
            if (lDirAlloc.ifExists(cachePath, conf)) {
              localPath = lDirAlloc.getLocalPathToRead(cachePath, conf);
            } else {
              localPath = lDirAlloc.getLocalPathForWrite(cachePath, fileStatus.getLen(), conf);
            }
            baseDir = localPath.toString().replace(cacheId, "");
            p[i] =
                DistributedCache.getLocalCache(
                    files[i],
                    conf,
                    new Path(baseDir),
                    fileStatus,
                    false,
                    Long.parseLong(fileTimestamps[i]),
                    new Path(workDir.getAbsolutePath()),
                    false);
          }
          DistributedCache.setLocalFiles(conf, stringifyPathArray(p));
        }
        Path localTaskFile = new Path(t.getJobFile());
        FileSystem localFs = FileSystem.getLocal(conf);
        localFs.delete(localTaskFile, true);
        OutputStream out = localFs.create(localTaskFile);
        try {
          conf.writeXml(out);
        } finally {
          out.close();
        }
      }

      if (!prepare()) {
        return;
      }

      String sep = System.getProperty("path.separator");
      StringBuffer classPath = new StringBuffer();
      // start with same classpath as parent process
      classPath.append(System.getProperty("java.class.path"));
      classPath.append(sep);
      if (!workDir.mkdirs()) {
        if (!workDir.isDirectory()) {
          LOG.fatal("Mkdirs failed to create " + workDir.toString());
        }
      }

      String jar = conf.getJar();
      if (jar != null) {
        // if jar exists, it into workDir
        File[] libs = new File(jobCacheDir, "lib").listFiles();
        if (libs != null) {
          for (int i = 0; i < libs.length; i++) {
            classPath.append(sep); // add libs from jar to classpath
            classPath.append(libs[i]);
          }
        }
        classPath.append(sep);
        classPath.append(new File(jobCacheDir, "classes"));
        classPath.append(sep);
        classPath.append(jobCacheDir);
      }

      // include the user specified classpath

      // archive paths
      Path[] archiveClasspaths = DistributedCache.getArchiveClassPaths(conf);
      if (archiveClasspaths != null && archives != null) {
        Path[] localArchives = DistributedCache.getLocalCacheArchives(conf);
        if (localArchives != null) {
          for (int i = 0; i < archives.length; i++) {
            for (int j = 0; j < archiveClasspaths.length; j++) {
              if (archives[i].getPath().equals(archiveClasspaths[j].toString())) {
                classPath.append(sep);
                classPath.append(localArchives[i].toString());
              }
            }
          }
        }
      }
      // file paths
      Path[] fileClasspaths = DistributedCache.getFileClassPaths(conf);
      if (fileClasspaths != null && files != null) {
        Path[] localFiles = DistributedCache.getLocalCacheFiles(conf);
        if (localFiles != null) {
          for (int i = 0; i < files.length; i++) {
            for (int j = 0; j < fileClasspaths.length; j++) {
              if (files[i].getPath().equals(fileClasspaths[j].toString())) {
                classPath.append(sep);
                classPath.append(localFiles[i].toString());
              }
            }
          }
        }
      }

      classPath.append(sep);
      classPath.append(workDir);
      //  Build exec child jmv args.
      Vector<String> vargs = new Vector<String>(8);
      File jvm = // use same jvm as parent
          new File(new File(System.getProperty("java.home"), "bin"), "java");

      vargs.add(jvm.toString());

      // Add child (task) java-vm options.
      //
      // The following symbols if present in mapred.child.java.opts value are
      // replaced:
      // + @taskid@ is interpolated with value of TaskID.
      // Other occurrences of @ will not be altered.
      //
      // Example with multiple arguments and substitutions, showing
      // jvm GC logging, and start of a passwordless JVM JMX agent so can
      // connect with jconsole and the likes to watch child memory, threads
      // and get thread dumps.
      //
      //  <property>
      //    <name>mapred.child.java.opts</name>
      //    <value>-verbose:gc -Xloggc:/tmp/@[email protected] \
      //           -Dcom.sun.management.jmxremote.authenticate=false \
      //           -Dcom.sun.management.jmxremote.ssl=false \
      //    </value>
      //  </property>
      //
      String javaOpts = conf.get("mapred.child.java.opts", "-Xmx200m");
      javaOpts = javaOpts.replace("@taskid@", taskid.toString());
      String[] javaOptsSplit = javaOpts.split(" ");

      // Add java.library.path; necessary for loading native libraries.
      //
      // 1. To support native-hadoop library i.e. libhadoop.so, we add the
      //    parent processes' java.library.path to the child.
      // 2. We also add the 'cwd' of the task to it's java.library.path to help
      //    users distribute native libraries via the DistributedCache.
      // 3. The user can also specify extra paths to be added to the
      //    java.library.path via mapred.child.java.opts.
      //
      String libraryPath = System.getProperty("java.library.path");
      if (libraryPath == null) {
        libraryPath = workDir.getAbsolutePath();
      } else {
        libraryPath += sep + workDir;
      }
      boolean hasUserLDPath = false;
      for (int i = 0; i < javaOptsSplit.length; i++) {
        if (javaOptsSplit[i].startsWith("-Djava.library.path=")) {
          javaOptsSplit[i] += sep + libraryPath;
          hasUserLDPath = true;
          break;
        }
      }
      if (!hasUserLDPath) {
        vargs.add("-Djava.library.path=" + libraryPath);
      }
      for (int i = 0; i < javaOptsSplit.length; i++) {
        vargs.add(javaOptsSplit[i]);
      }

      // add java.io.tmpdir given by mapred.child.tmp
      String tmp = conf.get("mapred.child.tmp", "./tmp");
      Path tmpDir = new Path(tmp);

      // if temp directory path is not absolute
      // prepend it with workDir.
      if (!tmpDir.isAbsolute()) {
        tmpDir = new Path(workDir.toString(), tmp);
      }
      FileSystem localFs = FileSystem.getLocal(conf);
      if (!localFs.mkdirs(tmpDir) && !localFs.getFileStatus(tmpDir).isDir()) {
        throw new IOException("Mkdirs failed to create " + tmpDir.toString());
      }
      vargs.add("-Djava.io.tmpdir=" + tmpDir.toString());

      // Add classpath.
      vargs.add("-classpath");
      vargs.add(classPath.toString());

      // Setup the log4j prop
      long logSize = TaskLog.getTaskLogLength(conf);
      vargs.add(
          "-Dhadoop.log.dir=" + new File(System.getProperty("hadoop.log.dir")).getAbsolutePath());
      vargs.add("-Dhadoop.root.logger=INFO,TLA");
      vargs.add("-Dhadoop.tasklog.taskid=" + taskid);
      vargs.add("-Dhadoop.tasklog.totalLogFileSize=" + logSize);

      if (conf.getProfileEnabled()) {
        if (conf.getProfileTaskRange(t.isMapTask()).isIncluded(t.getPartition())) {
          File prof = TaskLog.getTaskLogFile(taskid, TaskLog.LogName.PROFILE);
          vargs.add(String.format(conf.getProfileParams(), prof.toString()));
        }
      }

      // Add main class and its arguments
      vargs.add(Child.class.getName()); // main of Child
      // pass umbilical address
      InetSocketAddress address = tracker.getTaskTrackerReportAddress();
      vargs.add(address.getAddress().getHostAddress());
      vargs.add(Integer.toString(address.getPort()));
      vargs.add(taskid.toString()); // pass task identifier

      String pidFile = null;
      if (tracker.isTaskMemoryManagerEnabled()) {
        pidFile =
            lDirAlloc
                .getLocalPathForWrite(
                    (TaskTracker.getPidFilesSubdir() + Path.SEPARATOR + taskid), this.conf)
                .toString();
      }

      // set memory limit using ulimit if feasible and necessary ...
      String[] ulimitCmd = Shell.getUlimitMemoryCommand(conf);
      List<String> setup = null;
      if (ulimitCmd != null) {
        setup = new ArrayList<String>();
        for (String arg : ulimitCmd) {
          setup.add(arg);
        }
      }

      // Set up the redirection of the task's stdout and stderr streams
      File stdout = TaskLog.getTaskLogFile(taskid, TaskLog.LogName.STDOUT);
      File stderr = TaskLog.getTaskLogFile(taskid, TaskLog.LogName.STDERR);
      stdout.getParentFile().mkdirs();
      tracker.getTaskTrackerInstrumentation().reportTaskLaunch(taskid, stdout, stderr);

      Map<String, String> env = new HashMap<String, String>();
      StringBuffer ldLibraryPath = new StringBuffer();
      ldLibraryPath.append(workDir.toString());
      String oldLdLibraryPath = null;
      oldLdLibraryPath = System.getenv("LD_LIBRARY_PATH");
      if (oldLdLibraryPath != null) {
        ldLibraryPath.append(sep);
        ldLibraryPath.append(oldLdLibraryPath);
      }
      env.put("LD_LIBRARY_PATH", ldLibraryPath.toString());
      jvmManager.launchJvm(
          this,
          jvmManager.constructJvmEnv(
              setup, vargs, stdout, stderr, logSize, workDir, env, pidFile, conf));
      synchronized (lock) {
        while (!done) {
          lock.wait();
        }
      }
      tracker.getTaskTrackerInstrumentation().reportTaskEnd(t.getTaskID());
      if (exitCodeSet) {
        if (!killed && exitCode != 0) {
          if (exitCode == 65) {
            tracker.getTaskTrackerInstrumentation().taskFailedPing(t.getTaskID());
          }
          throw new IOException("Task process exit with nonzero status of " + exitCode + ".");
        }
      }
    } catch (FSError e) {
      LOG.fatal("FSError", e);
      try {
        tracker.fsError(t.getTaskID(), e.getMessage());
      } catch (IOException ie) {
        LOG.fatal(t.getTaskID() + " reporting FSError", ie);
      }
    } catch (Throwable throwable) {
      LOG.warn(t.getTaskID() + " Child Error", throwable);
      ByteArrayOutputStream baos = new ByteArrayOutputStream();
      throwable.printStackTrace(new PrintStream(baos));
      try {
        tracker.reportDiagnosticInfo(t.getTaskID(), baos.toString());
      } catch (IOException e) {
        LOG.warn(t.getTaskID() + " Reporting Diagnostics", e);
      }
    } finally {
      try {
        URI[] archives = DistributedCache.getCacheArchives(conf);
        URI[] files = DistributedCache.getCacheFiles(conf);
        if (archives != null) {
          for (int i = 0; i < archives.length; i++) {
            DistributedCache.releaseCache(archives[i], conf);
          }
        }
        if (files != null) {
          for (int i = 0; i < files.length; i++) {
            DistributedCache.releaseCache(files[i], conf);
          }
        }
      } catch (IOException ie) {
        LOG.warn("Error releasing caches : Cache files might not have been cleaned up");
      }
      tracker.reportTaskFinished(t.getTaskID(), false);
      if (t.isMapTask()) {
        tracker.addFreeMapSlot();
      } else {
        tracker.addFreeReduceSlot();
      }
    }
  }
  public void generateFileDetails(JspWriter out, HttpServletRequest req, Configuration conf)
      throws IOException, InterruptedException {

    int chunkSizeToView = 0;
    long startOffset = 0;
    int datanodePort;

    String blockIdStr = null;
    long currBlockId = 0;
    blockIdStr = req.getParameter("blockId");
    if (blockIdStr == null) {
      out.print("Invalid input (blockId absent)");
      return;
    }
    currBlockId = Long.parseLong(blockIdStr);

    String datanodePortStr = req.getParameter("datanodePort");
    if (datanodePortStr == null) {
      out.print("Invalid input (datanodePort absent)");
      return;
    }
    datanodePort = Integer.parseInt(datanodePortStr);

    String namenodeInfoPortStr = req.getParameter("namenodeInfoPort");
    int namenodeInfoPort = -1;
    if (namenodeInfoPortStr != null) namenodeInfoPort = Integer.parseInt(namenodeInfoPortStr);

    String chunkSizeToViewStr = req.getParameter("chunkSizeToView");
    if (chunkSizeToViewStr != null && Integer.parseInt(chunkSizeToViewStr) > 0) {
      chunkSizeToView = Integer.parseInt(chunkSizeToViewStr);
    } else {
      chunkSizeToView = JspHelper.getDefaultChunkSize(conf);
    }

    String startOffsetStr = req.getParameter("startOffset");
    if (startOffsetStr == null || Long.parseLong(startOffsetStr) < 0) startOffset = 0;
    else startOffset = Long.parseLong(startOffsetStr);

    String filename = HtmlQuoting.unquoteHtmlChars(req.getParameter("filename"));
    if (filename == null || filename.length() == 0) {
      out.print("Invalid input");
      return;
    }

    String blockSizeStr = req.getParameter("blockSize");
    long blockSize = 0;
    if (blockSizeStr == null || blockSizeStr.length() == 0) {
      out.print("Invalid input");
      return;
    }
    blockSize = Long.parseLong(blockSizeStr);

    String tokenString = req.getParameter(JspHelper.DELEGATION_PARAMETER_NAME);
    UserGroupInformation ugi = JspHelper.getUGI(req, conf);
    DFSClient dfs = JspHelper.getDFSClient(ugi, jspHelper.nameNodeAddr, conf);
    List<LocatedBlock> blocks =
        dfs.namenode.getBlockLocations(filename, 0, Long.MAX_VALUE).getLocatedBlocks();
    // Add the various links for looking at the file contents
    // URL for downloading the full file
    String downloadUrl =
        "http://"
            + req.getServerName()
            + ":"
            + +req.getServerPort()
            + "/streamFile"
            + URLEncoder.encode(filename, "UTF-8")
            + "?"
            + JspHelper.DELEGATION_PARAMETER_NAME
            + "="
            + tokenString;
    out.print("<a name=\"viewOptions\"></a>");
    out.print("<a href=\"" + downloadUrl + "\">Download this file</a><br>");

    DatanodeInfo chosenNode;
    // URL for TAIL
    LocatedBlock lastBlk = blocks.get(blocks.size() - 1);
    long blockId = lastBlk.getBlock().getBlockId();
    try {
      chosenNode = jspHelper.bestNode(lastBlk);
    } catch (IOException e) {
      out.print(e.toString());
      dfs.close();
      return;
    }
    String fqdn = InetAddress.getByName(chosenNode.getHost()).getCanonicalHostName();
    String tailUrl =
        "http://"
            + fqdn
            + ":"
            + chosenNode.getInfoPort()
            + "/tail.jsp?filename="
            + URLEncoder.encode(filename, "UTF-8")
            + "&namenodeInfoPort="
            + namenodeInfoPort
            + "&chunkSizeToView="
            + chunkSizeToView
            + "&referrer="
            + URLEncoder.encode(req.getRequestURL() + "?" + req.getQueryString(), "UTF-8")
            + JspHelper.getDelegationTokenUrlParam(tokenString);
    out.print("<a href=\"" + tailUrl + "\">Tail this file</a><br>");

    out.print("<form action=\"/browseBlock.jsp\" method=GET>");
    out.print("<b>Chunk size to view (in bytes, up to file's DFS block size): </b>");
    out.print("<input type=\"hidden\" name=\"blockId\" value=\"" + currBlockId + "\">");
    out.print("<input type=\"hidden\" name=\"blockSize\" value=\"" + blockSize + "\">");
    out.print("<input type=\"hidden\" name=\"startOffset\" value=\"" + startOffset + "\">");
    out.print("<input type=\"hidden\" name=\"filename\" value=\"" + filename + "\">");
    out.print("<input type=\"hidden\" name=\"datanodePort\" value=\"" + datanodePort + "\">");
    out.print(
        "<input type=\"hidden\" name=\"namenodeInfoPort\" value=\"" + namenodeInfoPort + "\">");
    out.print(
        "<input type=\"text\" name=\"chunkSizeToView\" value="
            + chunkSizeToView
            + " size=10 maxlength=10>");
    out.print("&nbsp;&nbsp;<input type=\"submit\" name=\"submit\" value=\"Refresh\">");
    out.print("</form>");
    out.print("<hr>");
    out.print("<a name=\"blockDetails\"></a>");
    out.print("<B>Total number of blocks: " + blocks.size() + "</B><br>");
    // generate a table and dump the info
    out.println("\n<table>");
    for (LocatedBlock cur : blocks) {
      out.print("<tr>");
      blockId = cur.getBlock().getBlockId();
      blockSize = cur.getBlock().getNumBytes();
      String blk = "blk_" + Long.toString(blockId);
      out.print("<td>" + Long.toString(blockId) + ":</td>");
      DatanodeInfo[] locs = cur.getLocations();
      for (int j = 0; j < locs.length; j++) {
        String datanodeAddr = locs[j].getName();
        datanodePort =
            Integer.parseInt(
                datanodeAddr.substring(datanodeAddr.indexOf(':') + 1, datanodeAddr.length()));
        fqdn = InetAddress.getByName(locs[j].getHost()).getCanonicalHostName();
        String blockUrl =
            "http://"
                + fqdn
                + ":"
                + locs[j].getInfoPort()
                + "/browseBlock.jsp?blockId="
                + Long.toString(blockId)
                + "&blockSize="
                + blockSize
                + "&filename="
                + URLEncoder.encode(filename, "UTF-8")
                + "&datanodePort="
                + datanodePort
                + "&genstamp="
                + cur.getBlock().getGenerationStamp()
                + "&namenodeInfoPort="
                + namenodeInfoPort
                + "&chunkSizeToView="
                + chunkSizeToView;
        out.print(
            "<td>&nbsp</td>" + "<td><a href=\"" + blockUrl + "\">" + datanodeAddr + "</a></td>");
      }
      out.println("</tr>");
    }
    out.println("</table>");
    out.print("<hr>");
    String namenodeHost = jspHelper.nameNodeAddr.getHostName();
    out.print(
        "<br><a href=\"http://"
            + InetAddress.getByName(namenodeHost).getCanonicalHostName()
            + ":"
            + namenodeInfoPort
            + "/dfshealth.jsp\">Go back to DFS home</a>");
    dfs.close();
  }
  public void generateFileChunks(JspWriter out, HttpServletRequest req, Configuration conf)
      throws IOException, InterruptedException {
    long startOffset = 0;
    int datanodePort = 0;
    int chunkSizeToView = 0;

    String namenodeInfoPortStr = req.getParameter("namenodeInfoPort");
    int namenodeInfoPort = -1;
    if (namenodeInfoPortStr != null) namenodeInfoPort = Integer.parseInt(namenodeInfoPortStr);

    String filename = HtmlQuoting.unquoteHtmlChars(req.getParameter("filename"));
    if (filename == null) {
      out.print("Invalid input (filename absent)");
      return;
    }

    String blockIdStr = null;
    long blockId = 0;
    blockIdStr = req.getParameter("blockId");
    if (blockIdStr == null) {
      out.print("Invalid input (blockId absent)");
      return;
    }
    blockId = Long.parseLong(blockIdStr);

    String tokenString = req.getParameter(JspHelper.DELEGATION_PARAMETER_NAME);
    UserGroupInformation ugi = JspHelper.getUGI(req, conf);
    final DFSClient dfs = JspHelper.getDFSClient(ugi, jspHelper.nameNodeAddr, conf);

    Token<BlockTokenIdentifier> accessToken = BlockTokenSecretManager.DUMMY_TOKEN;
    if (conf.getBoolean(DFSConfigKeys.DFS_BLOCK_ACCESS_TOKEN_ENABLE_KEY, false)) {
      List<LocatedBlock> blks =
          dfs.namenode.getBlockLocations(filename, 0, Long.MAX_VALUE).getLocatedBlocks();
      if (blks == null || blks.size() == 0) {
        out.print("Can't locate file blocks");
        dfs.close();
        return;
      }
      for (int i = 0; i < blks.size(); i++) {
        if (blks.get(i).getBlock().getBlockId() == blockId) {
          accessToken = blks.get(i).getBlockToken();
          break;
        }
      }
    }

    String blockGenStamp = null;
    long genStamp = 0;
    blockGenStamp = req.getParameter("genstamp");
    if (blockGenStamp == null) {
      out.print("Invalid input (genstamp absent)");
      return;
    }
    genStamp = Long.parseLong(blockGenStamp);

    String blockSizeStr;
    long blockSize = 0;
    blockSizeStr = req.getParameter("blockSize");
    if (blockSizeStr == null) {
      out.print("Invalid input (blockSize absent)");
      return;
    }
    blockSize = Long.parseLong(blockSizeStr);

    String chunkSizeToViewStr = req.getParameter("chunkSizeToView");
    if (chunkSizeToViewStr != null && Integer.parseInt(chunkSizeToViewStr) > 0)
      chunkSizeToView = Integer.parseInt(chunkSizeToViewStr);
    else chunkSizeToView = JspHelper.getDefaultChunkSize(conf);

    String startOffsetStr = req.getParameter("startOffset");
    if (startOffsetStr == null || Long.parseLong(startOffsetStr) < 0) startOffset = 0;
    else startOffset = Long.parseLong(startOffsetStr);

    String datanodePortStr = req.getParameter("datanodePort");
    if (datanodePortStr == null) {
      out.print("Invalid input (datanodePort absent)");
      return;
    }
    datanodePort = Integer.parseInt(datanodePortStr);
    out.print("<h3>File: ");
    JspHelper.printPathWithLinks(
        HtmlQuoting.quoteHtmlChars(filename), out, namenodeInfoPort, tokenString);
    out.print("</h3><hr>");
    String parent = new File(filename).getParent();
    JspHelper.printGotoForm(out, namenodeInfoPort, tokenString, HtmlQuoting.quoteHtmlChars(parent));
    out.print("<hr>");
    out.print(
        "<a href=\"http://"
            + req.getServerName()
            + ":"
            + req.getServerPort()
            + "/browseDirectory.jsp?dir="
            + URLEncoder.encode(parent, "UTF-8")
            + "&namenodeInfoPort="
            + namenodeInfoPort
            + "\"><i>Go back to dir listing</i></a><br>");
    out.print("<a href=\"#viewOptions\">Advanced view/download options</a><br>");
    out.print("<hr>");

    // Determine the prev & next blocks
    long nextStartOffset = 0;
    long nextBlockSize = 0;
    String nextBlockIdStr = null;
    String nextGenStamp = null;
    String nextHost = req.getServerName();
    int nextPort = req.getServerPort();
    int nextDatanodePort = datanodePort;
    // determine data for the next link
    if (startOffset + chunkSizeToView >= blockSize) {
      // we have to go to the next block from this point onwards
      List<LocatedBlock> blocks =
          dfs.namenode.getBlockLocations(filename, 0, Long.MAX_VALUE).getLocatedBlocks();
      for (int i = 0; i < blocks.size(); i++) {
        if (blocks.get(i).getBlock().getBlockId() == blockId) {
          if (i != blocks.size() - 1) {
            LocatedBlock nextBlock = blocks.get(i + 1);
            nextBlockIdStr = Long.toString(nextBlock.getBlock().getBlockId());
            nextGenStamp = Long.toString(nextBlock.getBlock().getGenerationStamp());
            nextStartOffset = 0;
            nextBlockSize = nextBlock.getBlock().getNumBytes();
            DatanodeInfo d = jspHelper.bestNode(nextBlock);
            String datanodeAddr = d.getName();
            nextDatanodePort =
                Integer.parseInt(
                    datanodeAddr.substring(datanodeAddr.indexOf(':') + 1, datanodeAddr.length()));
            nextHost = InetAddress.getByName(d.getHost()).getCanonicalHostName();
            nextPort = d.getInfoPort();
          }
        }
      }
    } else {
      // we are in the same block
      nextBlockIdStr = blockIdStr;
      nextStartOffset = startOffset + chunkSizeToView;
      nextBlockSize = blockSize;
      nextGenStamp = blockGenStamp;
    }
    String nextUrl = null;
    if (nextBlockIdStr != null) {
      nextUrl =
          "http://"
              + nextHost
              + ":"
              + nextPort
              + "/browseBlock.jsp?blockId="
              + nextBlockIdStr
              + "&blockSize="
              + nextBlockSize
              + "&startOffset="
              + nextStartOffset
              + "&genstamp="
              + nextGenStamp
              + "&filename="
              + URLEncoder.encode(filename, "UTF-8")
              + "&chunkSizeToView="
              + chunkSizeToView
              + "&datanodePort="
              + nextDatanodePort
              + "&namenodeInfoPort="
              + namenodeInfoPort
              + JspHelper.getDelegationTokenUrlParam(tokenString);
      out.print("<a href=\"" + nextUrl + "\">View Next chunk</a>&nbsp;&nbsp;");
    }
    // determine data for the prev link
    String prevBlockIdStr = null;
    String prevGenStamp = null;
    long prevStartOffset = 0;
    long prevBlockSize = 0;
    String prevHost = req.getServerName();
    int prevPort = req.getServerPort();
    int prevDatanodePort = datanodePort;
    if (startOffset == 0) {
      List<LocatedBlock> blocks =
          dfs.namenode.getBlockLocations(filename, 0, Long.MAX_VALUE).getLocatedBlocks();
      for (int i = 0; i < blocks.size(); i++) {
        if (blocks.get(i).getBlock().getBlockId() == blockId) {
          if (i != 0) {
            LocatedBlock prevBlock = blocks.get(i - 1);
            prevBlockIdStr = Long.toString(prevBlock.getBlock().getBlockId());
            prevGenStamp = Long.toString(prevBlock.getBlock().getGenerationStamp());
            prevStartOffset = prevBlock.getBlock().getNumBytes() - chunkSizeToView;
            if (prevStartOffset < 0) prevStartOffset = 0;
            prevBlockSize = prevBlock.getBlock().getNumBytes();
            DatanodeInfo d = jspHelper.bestNode(prevBlock);
            String datanodeAddr = d.getName();
            prevDatanodePort =
                Integer.parseInt(
                    datanodeAddr.substring(datanodeAddr.indexOf(':') + 1, datanodeAddr.length()));
            prevHost = InetAddress.getByName(d.getHost()).getCanonicalHostName();
            prevPort = d.getInfoPort();
          }
        }
      }
    } else {
      // we are in the same block
      prevBlockIdStr = blockIdStr;
      prevStartOffset = startOffset - chunkSizeToView;
      if (prevStartOffset < 0) prevStartOffset = 0;
      prevBlockSize = blockSize;
      prevGenStamp = blockGenStamp;
    }

    String prevUrl = null;
    if (prevBlockIdStr != null) {
      prevUrl =
          "http://"
              + prevHost
              + ":"
              + prevPort
              + "/browseBlock.jsp?blockId="
              + prevBlockIdStr
              + "&blockSize="
              + prevBlockSize
              + "&startOffset="
              + prevStartOffset
              + "&filename="
              + URLEncoder.encode(filename, "UTF-8")
              + "&chunkSizeToView="
              + chunkSizeToView
              + "&genstamp="
              + prevGenStamp
              + "&datanodePort="
              + prevDatanodePort
              + "&namenodeInfoPort="
              + namenodeInfoPort
              + JspHelper.getDelegationTokenUrlParam(tokenString);
      out.print("<a href=\"" + prevUrl + "\">View Prev chunk</a>&nbsp;&nbsp;");
    }
    out.print("<hr>");
    out.print("<textarea cols=\"100\" rows=\"25\" wrap=\"virtual\" style=\"width:100%\" READONLY>");
    try {
      jspHelper.streamBlockInAscii(
          new InetSocketAddress(req.getServerName(), datanodePort),
          blockId,
          accessToken,
          genStamp,
          blockSize,
          startOffset,
          chunkSizeToView,
          out,
          conf);
    } catch (Exception e) {
      out.print(e);
    }
    out.print("</textarea>");
    dfs.close();
  }