Question

我想创建一个包含三个Hadoop作业的链，其中一个作业的输出作为第二个作业的输入提供，依此类推。我想在不使用Oozie的情况下这样做。

我已经编写了以下代码来实现它： -

public class TfIdf {
    public static void main(String args[]) throws IOException, InterruptedException, ClassNotFoundException
    {
        TfIdf tfIdf = new TfIdf();
        tfIdf.runWordCount();
        tfIdf.runDocWordCount();
        tfIdf.TFIDFComputation();
    }

    public void runWordCount() throws IOException, InterruptedException, ClassNotFoundException
    {
        Job job = new Job();


        job.setJarByClass(TfIdf.class);
        job.setJobName("Word Count calculation");

        job.setMapperClass(WordFrequencyMapper.class);
        job.setReducerClass(WordFrequencyReducer.class);

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

        FileInputFormat.setInputPaths(job, new Path("input"));
        FileOutputFormat.setOutputPath(job, new Path("ouput"));

        job.waitForCompletion(true);
    }

    public void runDocWordCount() throws IOException, InterruptedException, ClassNotFoundException
    {
        Job job = new Job();

        job.setJarByClass(TfIdf.class);
        job.setJobName("Word Doc count calculation");

        job.setMapperClass(WordCountDocMapper.class);
        job.setReducerClass(WordCountDocReducer.class);

        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(Text.class);

        FileInputFormat.setInputPaths(job, new Path("output"));
        FileOutputFormat.setOutputPath(job, new Path("ouput_job2"));

        job.waitForCompletion(true);
    }

    public void TFIDFComputation() throws IOException, InterruptedException, ClassNotFoundException
    {
        Job job = new Job();

        job.setJarByClass(TfIdf.class);
        job.setJobName("TFIDF calculation");

        job.setMapperClass(TFIDFMapper.class);
        job.setReducerClass(TFIDFReducer.class);

        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(Text.class);

        FileInputFormat.setInputPaths(job, new Path("output_job2"));
        FileOutputFormat.setOutputPath(job, new Path("ouput_job3"));

        job.waitForCompletion(true);
    }
}

然而我收到错误：

Input path does not exist: hdfs://localhost.localdomain:8020/user/cloudera/output

有人可以帮我解决这个问题吗？

Answer 1

这个答案有点晚了，但是......这只是你名字中的一个简单错字。你已经把你的第一份工作的输出写成dir“ouput”，你的第二份工作就是在“输出”中寻找它。

如何在不使用OOzie的情况下创建Hadoop作业链

1 个答案: