线程“main”中的异常org.apache.Hadoop.mapred.InvalidJobConfException：未在JobConf中设置输出目录

Question

我是新的Hadoop用户。我的程序是跳过mapreduce中的错误记录数据。我没有跳过坏数据所以首先，我不是试图跳过数据，我想找到发生的错误。所以，我添加mycustomrunjob（）来知道为什么我不能跳过坏记录。目前，我删除了跳过编码行。我运行这个程序时遇到问题，虽然我已经设置了输出文件路径：

import java.io.IOException;
import org.apache.hadoop.conf.* ;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.* ;
import org.apache.hadoop.mapred.* ;
import org.apache.hadoop.mapred.lib.* ;

public class SkipData
{  
public static class MapClass extends MapReduceBase implements Mapper<LongWritable, Text, Text, LongWritable>
{
 private final static LongWritable one = new LongWritable(1);
private Text word = new Text("totalcount");
public void map(LongWritable key, Text value, OutputCollector<Text, LongWritable> output, Reporter reporter) throws IOException
{
String line = value.toString();
if (line.equals("skiptext"))
throw new RuntimeException("Found skiptext") ;

output.collect(word, one);

}
}
public static RunningJob myCustomRunJob(JobConf job) throws Exception {
JobClient jc = new JobClient(job);
RunningJob rj = jc.submitJob(job);
if (!jc.monitorAndPrintJob(job, rj)) {
  throw new IOException("Job failed with info: " + rj.getFailureInfo());
}
return rj;
}
public static void main(String[] args) throws Exception
{
System.setProperty("hadoop.home.dir", "/");
Configuration config = new Configuration() ;
JobConf conf = new JobConf(config, SkipData.class);
RunningJob result=myCustomRunJob(conf);

conf.setJobName("SkipData");

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

conf.setMapperClass(MapClass.class);
conf.setCombinerClass(LongSumReducer.class);
conf.setReducerClass(LongSumReducer.class);

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

JobClient.runJob(conf);
}
}

我试图多次完成此错误。我使用的是旧API。如何解决这个问题？

18/02/28 11:05:28 DEBUG security.UserGroupInformation:  PrivilegedActionException as:saung (auth:SIMPLE) cause:org.apache.hadoop.mapred.InvalidJobConfException: Output directory not set in JobConf.
18/02/28 11:05:28 DEBUG security.UserGroupInformation: PrivilegedActionException as:saung (auth:SIMPLE) cause:org.apache.hadoop.mapred.InvalidJobConfException: Output directory not set in JobConf.
Exception in thread "main"  org.apache.hadoop.mapred.InvalidJobConfException: Output directory not set in JobConf.
 at  org.apache.hadoop.mapred.FileOutputFormat.checkOutputSpecs(FileOutputFormat.ja va:117)
 at org.apache.hadoop.mapreduce.JobSubmitter.checkSpecs(JobSubmitter.java:268)
 at org.apache.hadoop.mapreduce.JobSubmitter.submitJobInternal(JobSubmitter.java:139)
 at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1290)
 at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1287)
 at java.security.AccessController.doPrivileged(Native Method)
 at javax.security.auth.Subject.doAs(Subject.java:422)
 at  org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1746)
 at org.apache.hadoop.mapreduce.Job.submit(Job.java:1287)
 at org.apache.hadoop.mapred.JobClient$1.run(JobClient.java:575)
 at org.apache.hadoop.mapred.JobClient$1.run(JobClient.java:570)
 at java.security.AccessController.doPrivileged(Native Method)
 at javax.security.auth.Subject.doAs(Subject.java:422)
 at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1746)
 at org.apache.hadoop.mapred.JobClient.submitJobInternal(JobClient.java:570)
 at org.apache.hadoop.mapred.JobClient.submitJob(JobClient.java:561)
 at mapredpack.SkipData.myCustomRunJob(SkipData.java:90)
 at mapredpack.SkipData.main(SkipData.java:140)

Answer 1

你试图通过调用两次来运行这项工作

RunningJob result=myCustomRunJob(conf);

如此早，您的工作将失败，因为在该阶段没有设置任何配置。我会删除该行（和myCustomRunJob(JobConf job)方法）。最底层的JobClient.runJob(conf)将处理这项工作。

Answer 2

代码中有两个问题。

1. 您是第一次调用该作业而不设置任何输入/输出路径。
2. 此外，您正在尝试重新提交作业，该作业必然会失败（因为每个MR作业都需要一个新的输出目录）。

像这样改变你的主要方法：

public static void main(String[] args) throws Exception
{
System.setProperty("hadoop.home.dir", "/");
Configuration config = new Configuration() ;
JobConf conf = new JobConf(config, SkipData.class);

conf.setJobName("SkipData");

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

conf.setMapperClass(MapClass.class);
conf.setCombinerClass(LongSumReducer.class);
conf.setReducerClass(LongSumReducer.class);

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

RunningJob result=myCustomRunJob(conf);
}