启动hadoop 2.2.0 minicluster时出错:java.lang.NoClassDefFoundError:org/apache/hadoop/yarn/server/MiniYARNCluster

Question

我在MacOS开发环境中使用Apache Hadoop 2.2.0.当尝试运行hadoop minicluster时,如apache文档中所述:

hadoop jar ./share/hadoop/mapreduce/hadoop-mapreduce-client-jobclient-2.2.0-tests.jar  minicluster

我收到了错误

java.lang.NoClassDefFoundError:org/apache/hadoop/yarn/server/MiniYARNCluster org.apache.hadoop.mapreduce.MiniHadoopClusterManager.start(MiniHadoopClusterManager.java:170)org.apache.hadoop.mapreduce.MiniHadoopClusterManager.run(MiniHadoopClusterManager) .java:129)at.......

任何想法如何解决这个问题？

Answer 1

看起来我找到了解决方案:默认情况下,包含MiniYARNCluster的jar文件不是Hadoop类路径的一部分,必须将其显式添加到HADOOP_CLASSPATH中.下面的代码片段工作正常:

export HADOOP_CLASSPATH=./share/hadoop/yarn/test/hadoop-yarn-server-tests-2.2.0-tests.jar
./bin/hadoop jar ./share/hadoop/mapreduce/hadoop-mapreduce-client-jobclient-2.2.0-tests.jar  minicluster