java - Hadoop无法运行程序

Question

嗨，这是我使用 hadoop 的第一个程序，我修改了 wordcount 程序。我无法执行这个程序。我已将映射输出和 reducer 输入更改为 <text text> 。输入文件包含记录为 email gender age 21 。执行挂起，显示 Map 100% Reduce 100% 。

//MAPPER
public class WordMapper extends MapReduceBase implements
    Mapper<LongWritable, Text, Text, Text> {

  @Override
  public void map(LongWritable key, Text value,
      OutputCollector<Text, Text> output, Reporter reporter)
      throws IOException {
    String s = value.toString();
    String s1;
    Matcher m2;
    FileSplit filesplit = (FileSplit) reporter.getInputSplit();
    String fileName = filesplit.getPath().getName();

    Pattern p1 = Pattern.compile("\\s+email\\s+gender\\s+age\\s+(\\S+)$");
    m2=p1.matcher(s);
    if (m2.find()){
        s1 = m2.replaceFirst("omitted");
        output.collect(new Text(s1), new Text(fileName));
    }
  }
}

    //REDUCER
public class SumReducer extends MapReduceBase implements
    Reducer<Text, Text, Text, IntWritable> {

  @Override
  public void reduce(Text key, Iterator<Text> values,
      OutputCollector<Text, IntWritable> output, Reporter reporter)
      throws IOException {

    int cliCount = 0;
    while (values.hasNext()) {
      cliCount += 1;
    }
    output.collect(key, new IntWritable(cliCount));
  }
}

    //MAIN
public class WordCount extends Configured implements Tool {

  @Override
  public int run(String[] args) throws Exception {

    if (args.length != 2) {
      System.out.printf(
          "Usage: %s [generic options] <input dir> <output dir>\n", getClass()
              .getSimpleName());
      ToolRunner.printGenericCommandUsage(System.out);
      return -1;
    }

    JobConf conf = new JobConf(getConf(), WordCount.class);
    conf.setJobName(this.getClass().getName());

    FileInputFormat.setInputPaths(conf, new Path(args[0]));
    FileOutputFormat.setOutputPath(conf, new Path(args[1]));

    conf.setMapperClass(WordMapper.class);
    conf.setReducerClass(SumReducer.class);

    conf.setMapOutputKeyClass(Text.class);
    conf.setMapOutputValueClass(Text.class);

    conf.setOutputKeyClass(Text.class);
    conf.setOutputValueClass(IntWritable.class);

    JobClient.runJob(conf);
    return 0;
  }

  public static void main(String[] args) throws Exception {
    int exitCode = ToolRunner.run(new WordCount(), args);
    System.exit(exitCode);
  }
}

更新:仅在 _log 文件夹 .xml 内文件存在

我让程序继续执行，hadoop 杀死了它。

3/06/19 15:02:47 INFO mapred.JobClient:     Total committed heap usage (bytes)=258875392
13/06/19 15:02:47 INFO mapred.JobClient:   org.apache.hadoop.mapreduce.lib.input.FileInputFormatCounter
13/06/19 15:02:47 INFO mapred.JobClient:     BYTES_READ=26
13/06/19 15:02:47 INFO mapred.JobClient: Job Failed: NA
Exception in thread "main" java.io.IOException: Job failed!
    at org.apache.hadoop.mapred.JobClient.runJob(JobClient.java:1322)
    at WordCount.run(WordCount.java:41)
    at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
    at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:84)
    at WordCount.main(WordCount.java:46)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at org.apache.hadoop.util.RunJar.main(RunJar.java:208)

Answer 1

我在 reducer 中遇到了问题。由于实现错误，迭代器没有继续前进。

    while (values.hasNext()) {
      cliCount += 1;
      //values.next(); This was missing. Adding this runs the code perfectly.
    }