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我试图使用分布式缓存的新api来运行hadoop程序。我被困在下面的错误消息。使用分布式缓存的新api的问题
14/11/04 10:54:36 WARN fs.FileUtil: Command 'ln -s /tmp/hadoop-hduser/mapred/local/1415078671812/normal_small /home/yogi/Desktop/normal_small' failed 1 with: ln: failed to create symbolic link ‘/home/yogi/Desktop/normal_small’: Permission denied
14/11/04 10:54:36 WARN mapred.LocalDistributedCacheManager: Failed to create symlink: /tmp/hadoop-hduser/mapred/local/1415078671812/normal_small <- /home/yogi/Desktop/normal_small
java.io.FileNotFoundException: hdfs:/master:54310/usr/local/hadoop/input/normal_small (No such file or directory)
我从来没有在我的代码中提到关于/ home/yogi/Desktop/normal_small的任何信息。无法理解它试图访问该文件的位置。
另外,我应该如何给驱动程序类中的输入文件路径解决文件未找到异常?
下面是我的映射器和驱动程序类摘要:
映射:
BufferedReader in = null;
FileReader fr = null;
private List<String> list = new ArrayList<String>();
@Override
protected void setup(Context context)
throws IOException, InterruptedException {
Configuration conf = context.getConfiguration();
URI[] cacheFiles = context.getCacheFiles();
try {
fr = new FileReader(cacheFiles[0].toString());
in = new BufferedReader(fr);
String str;
while ((str = in.readLine()) != null) {
list.add(str);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
in.close();
fr.close();
}
}
public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
FileOutputStream fos = new FileOutputStream("output");
ObjectOutputStream oos = new ObjectOutputStream(fos);
oos.writeObject(list); // write MenuArray to ObjectOutputStream
BufferedReader br=new BufferedReader(new FileReader("output"));
String line=br.readLine();
.........
}
司机:
Job job = Job.getInstance(getConf());
job.setJobName("wordcount");
job.setJarByClass(driver.class);
job.addCacheFile(new Path("hdfs://master:54310/usr/local/hadoop/input/normal_small").toUri());
我认为,'hdfs:// master:54310'部分根本不需要。然而,它并没有解释幻影路径的查找。 – blackSmith 2014-11-04 05:52:45
@blackSmith:错误依然存在。它显示文件未找到异常。我正在使用multinode hadoop cluster btw – re3el 2014-11-04 06:12:59
你的路径'/ usr/local/hadoop/input/normal_small'似乎指向一个本地文件。该文件应该在HDFS中缓存在节点上。 – blackSmith 2014-11-04 06:29:36