我正在关注“Hadoop：The Definitive Guide 2 / e”一书的例子。 我遇到了一个问题.. :-(。
我使用的是ubuntu 12.04，hadoop 2.2.0。 我用eclipse做了job.jar。 map_reduce.programming.v1.MaxTemperatureReducer类在jar中，但不同的包。 当我开始工作时，我遇到的课程没有找到异常。
以下是 mapred-site.xml
<configuration>
<property>
<name>mapreduce.framework.name</name>
<value>yarn</value>
</property>
</configuration>
如果将值更改为local而不是yarn，则可以正常工作。但是在纱线的情况下，没有工作。 HADOOP_CLASS_PATH包括包含job.jar的路径。 根本原因是什么？
package map_reduce.programming.v3;
import map_reduce.programming.v1.MaxTemperatureReducer;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.FileInputFormat;
import org.apache.hadoop.mapred.FileOutputFormat;
import org.apache.hadoop.mapred.JobClient;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
/**
* hadoop map_reduce.programming.v3.MaxTemperatureDriver -conf conf/hadoop-local.xml /book/input/ncdc/micro max-temp
* hadoop jar job.jar map_reduce.programming.v3.MaxTemperatureDriver -conf conf/hadoop-cluster.xml /book/input/ncdc/all max-temp
*
*
*/
public class MaxTemperatureDriver extends Configured implements Tool {
@Override
public int run(String[] args) throws Exception {
if (args.length != 2) {
System.err.printf("Usage: %s [generic optins] <input> <output>\n", getClass().getSimpleName());
ToolRunner.printGenericCommandUsage(System.err);
return -1;
}
JobConf conf = new JobConf(getConf(), getClass());
conf.setJobName("Max temperature");
FileInputFormat.addInputPath(conf, new Path(args[0]));
FileOutputFormat.setOutputPath(conf, new Path(args[1]));
conf.setOutputKeyClass(Text.class);
conf.setOutputValueClass(IntWritable.class);
conf.setMapperClass(MaxTemperatureMapper.class);
conf.setCombinerClass(MaxTemperatureReducer.class);
conf.setReducerClass(MaxTemperatureReducer.class);
JobClient.runJob(conf);
return 0;
}
public static void main(String[] args) throws Exception {
int exitCode = ToolRunner.run(new MaxTemperatureDriver(), args);
System.exit(exitCode);
}
}
以下是日志..
jar job.jar map_reduce.programming.v3.MaxTemperatureDriver -conf conf / hadoop-cluster.xml / book / input / ncdc / all max-temp0991
14/06/05 18:10:20 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
14/06/05 18:10:20 INFO client.RMProxy: Connecting to ResourceManager at /0.0.0.0:8032
14/06/05 18:10:20 INFO client.RMProxy: Connecting to ResourceManager at /0.0.0.0:8032
14/06/05 18:10:20 WARN mapreduce.JobSubmitter: No job jar file set. User classes may not be found. See Job or Job#setJar(String).
14/06/05 18:10:20 INFO mapred.FileInputFormat: Total input paths to process : 2
14/06/05 18:10:21 INFO mapreduce.JobSubmitter: number of splits:2
14/06/05 18:10:21 INFO Configuration.deprecation: user.name is deprecated. Instead, use mapreduce.job.user.name
14/06/05 18:10:21 INFO Configuration.deprecation: mapred.output.value.class is deprecated. Instead, use mapreduce.job.output.value.class
14/06/05 18:10:21 INFO Configuration.deprecation: mapred.job.name is deprecated. Instead, use mapreduce.job.name
14/06/05 18:10:21 INFO Configuration.deprecation: mapred.input.dir is deprecated. Instead, use mapreduce.input.fileinputformat.inputdir
14/06/05 18:10:21 INFO Configuration.deprecation: mapred.output.dir is deprecated. Instead, use mapreduce.output.fileoutputformat.outputdir
14/06/05 18:10:21 INFO Configuration.deprecation: mapred.map.tasks is deprecated. Instead, use mapreduce.job.maps
14/06/05 18:10:21 INFO Configuration.deprecation: mapred.output.key.class is deprecated. Instead, use mapreduce.job.output.key.class
14/06/05 18:10:21 INFO Configuration.deprecation: mapred.working.dir is deprecated. Instead, use mapreduce.job.working.dir
14/06/05 18:10:22 INFO mapreduce.JobSubmitter: Submitting tokens for job: job_1401958773644_0002
14/06/05 18:10:22 INFO mapred.YARNRunner: Job jar is not present. Not adding any jar to the list of resources.
14/06/05 18:10:22 INFO impl.YarnClientImpl: Submitted application
application_1401958773644_0002 to ResourceManager at /0.0.0.0:8032
14/06/05 18:10:22 INFO mapreduce.Job: The url to track the job: http://ubuntu:8088/proxy/application_1401958773644_0002/
14/06/05 18:10:22 INFO mapreduce.Job: Running job: job_1401958773644_0002
14/06/05 18:10:27 INFO mapreduce.Job: Job job_1401958773644_0002 running in uber mode : false
14/06/05 18:10:27 INFO mapreduce.Job: map 0% reduce 0%
14/06/05 18:10:30 INFO mapreduce.Job: Task Id : attempt_1401958773644_0002_m_000001_0, Status : FAILED
Error: java.lang.RuntimeException: java.lang.RuntimeException: java.lang.ClassNotFoundException: Class map_reduce.programming.v1.MaxTemperatureReducer not found
at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:1752)
at org.apache.hadoop.mapred.JobConf.getCombinerClass(JobConf.java:1139)
at org.apache.hadoop.mapred.Task$CombinerRunner.create(Task.java:1517)
at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.init(MapTask.java:1010)
at org.apache.hadoop.mapred.MapTask.createSortingCollector(MapTask.java:390)
at org.apache.hadoop.mapred.MapTask.runOldMapper(MapTask.java:418)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:341)
at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:162)
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:1491)
at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:157)
答案 0 :(得分：0)
我有完全相同的问题，Job配置没有找到Mapper和Reducer类并抛出ClassNotFoundException。
我正在使用mapreduce2所以我不得不添加
job.setJarByClass(Avg.class);
虽然在你的情况下，我认为你应该打电话
JobConf conf = new JobConf(getConf(), YouClassMain.class);
最佳， 爱德华多