Hadoop MapReduce NoSuchElementException

Question

我想在具有两个节点的 FreeBSD-Cluster 上运行 MapReduce-Job，但出现以下异常

14/08/27 14:23:04 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
14/08/27 14:23:04 INFO Configuration.deprecation: session.id is deprecated. Instead, use dfs.metrics.session-id
14/08/27 14:23:04 INFO jvm.JvmMetrics: Initializing JVM Metrics with processName=JobTracker, sessionId=
14/08/27 14:23:04 WARN mapreduce.JobSubmitter: Hadoop command-line option parsing not performed. Implement the Tool interface and execute your application with ToolRunner to remedy this.
14/08/27 14:23:04 WARN mapreduce.JobSubmitter: No job jar file set.  User classes may not be found. See Job or Job#setJar(String).
14/08/27 14:23:04 INFO mapreduce.JobSubmitter: Cleaning up the staging area file:/tmp/hadoop-otlam/mapred/staging/otlam968414084/.staging/job_local968414084_0001
Exception in thread "main" java.util.NoSuchElementException
at java.util.StringTokenizer.nextToken(StringTokenizer.java:349)
at org.apache.hadoop.fs.RawLocalFileSystem$DeprecatedRawLocalFileStatus.loadPermissionInfo(RawLocalFileSystem.java:565)
at org.apache.hadoop.fs.RawLocalFileSystem$DeprecatedRawLocalFileStatus.getPermission(RawLocalFileSystem.java:534)
at org.apache.hadoop.mapreduce.filecache.ClientDistributedCacheManager.checkPermissionOfOther(ClientDistributedCacheManager.java:276)
at org.apache.hadoop.mapreduce.filecache.ClientDistributedCacheManager.isPublic(ClientDistributedCacheManager.java:240)
at org.apache.hadoop.mapreduce.filecache.ClientDistributedCacheManager.determineCacheVisibilities(ClientDistributedCacheManager.java:162)
at org.apache.hadoop.mapreduce.filecache.ClientDistributedCacheManager.determineTimestampsAndCacheVisibilities(ClientDistributedCacheManager.java:58)
at org.apache.hadoop.mapreduce.JobSubmitter.copyAndConfigureFiles(JobSubmitter.java:265)
at org.apache.hadoop.mapreduce.JobSubmitter.copyAndConfigureFiles(JobSubmitter.java:301)
at org.apache.hadoop.mapreduce.JobSubmitter.submitJobInternal(JobSubmitter.java:389)
at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1285)
at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1282)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1556)
at org.apache.hadoop.mapreduce.Job.submit(Job.java:1282)
at org.apache.hadoop.mapreduce.Job.waitForCompletion(Job.java:1303)
...

当我尝试在新的 MapReduce 作业上运行 job.watForCompletion(true); 时会发生这种情况。应该抛出 NoSuchElementException，因为在 StringTokenizer 中没有更多的 Elements 并且在其上调用了 next()。 我查看了源代码并在 RawLocalFileSystem.java 中找到了以下代码部分：

/// loads permissions, owner, and group from `ls -ld`
private void loadPermissionInfo() {
  IOException e = null;
  try {
    String output = FileUtil.execCommand(new File(getPath().toUri()), 
        Shell.getGetPermissionCommand());
    StringTokenizer t =
        new StringTokenizer(output, Shell.TOKEN_SEPARATOR_REGEX);
    //expected format
    //-rw-------    1 username groupname ...
    String permission = t.nextToken();

据我所见，Hadoop 尝试使用ls -ld 找出特定文件的一些权限，如果我在控制台中使用它，它会完美运行。不幸的是，我还没有找到它在寻找哪些文件权限。

Hadoop 版本是 2.4.1，HBase 版本是 0.98.4，我使用的是 Java-API。其他操作（例如创建表）工作正常。有没有人遇到过类似的问题或知道该怎么做？

编辑： 我刚刚发现这是一个与 hadoop 相关的问题。即使不使用 HDFS 进行最简单的 MapReduce-Operation 也会给我同样的异常。

Answer 1

您能否检查一下这是否可以解决您的问题。

如果您的问题是权限问题，那么这可行。

public static void main(String[] args) {
     //set user group information       
     UserGroupInformation ugi = UserGroupInformation.createRemoteUser("hdfs");
     //set privilege exception
     ugi.doAs(new PrivilegedExceptionAction<Void>() {
     public Void run() throws Exception {
                //create configuration object
                 Configuration config = new Configuration();
                 config.set("fs.defaultFS", "hdfs://ip:port/");
                 config.set("hadoop.job.ugi", "hdfs");
                 FileSystem dfs = FileSystem.get(config);
                 .
                 .