我知道这是很多问题的主题之一。在深入研究了所有可以找到的主题之后(大多数都在谈论CLASSPATH),我仍然无法解决我的问题。
我找到并尝试过的主题示例:
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/hadoop/hbase/HBaseConfiguration
java.lang.NoClassDefFoundError with HBase Scan
我在Ubuntu 14.04上将Hadoop 2.5.1与HBase 0.98.11结合使用
我设置了伪分布式模式,并成功使用hbase运行hadoop。我要设置完全分布式模式后,作业将失败,并显示NoClassDefFound错误。我尝试将“export HADOOP_CLASSPATH = /usr/local/hbase-0.98.11-hadoop2/bin/hbase classpath
”添加到hadoop-env(也包括yarn-env)中,但仍然无法正常工作。
我发现的一个通知是,如果我评论
<property>
<name>mapreduce.framework.name</name>
<value>yarn</value>
</property>
我可以成功运行作业。但是似乎我在单节点而不是多节点上运行它。
以下是一些配置:
映射站点
<property>
<name>mapred.job.tracker</name>
<value>hadoop1:54311</value>
<description>The host and port that the MapReduce job tracker runs
at. If "local", then jobs are run in-process as a single map
and reduce task.
</description>
</property>
<property>
<name>mapreduce.framework.name</name>
<value>yarn</value>
</property>`
hdfs站点
<property>
<name>dfs.replication</name>
<value>2</value>
<description>Default block replication.
The actual number of replications can be specified when the file is created.
The default is used if replication is not specified in create time.
</description>
</property>
<property>
<name>dfs.namenode.name.dir</name>
<value>file:/usr/local/hadoop_store/hdfs/namenode</value>
</property>
<property>
<name>dfs.datanode.data.dir</name>
<value>file:/usr/local/hadoop_store/hdfs/datanode</value>
</property>
<property>
<name>dfs.datanode.use.datanode.hostname</name>
<value>false</value>
</property>
<property>
<name>dfs.namenode.datanode.registration.ip-hostname-check</name>
<value>false</value>
</property>
<property>
<name>dfs.permissions</name>
<value>false</value>
</property>
yarn 现场
<property>
<name>yarn.nodemanager.aux-services</name>
<value>mapreduce_shuffle</value>
<description>shuffle service that needs to be set for Map Reduce to run
</description>
</property>
<property>
<name>yarn.nodemanager.aux-services.mapreduce_shuffle.class</name>
<value>org.apache.hadoop.mapred.ShuffleHandler</value>
</property>
在yarn-env和hadoop-env中,除了HADOOP_CLASSPATH以外,它都是默认值(即使我添加也没有改变,它也不会改变。)
这是错误跟踪:
2015-04-25 23:29:25,143 FATAL [main] org.apache.hadoop.mapred.YarnChild: Error running child : java.lang.NoClassDefFoundError: org/apache/hadoop/hbase/HBaseConfiguration at apriori2$FrequentItemsReduce.reduce(apriori2.java:550) at apriori2$FrequentItemsReduce.reduce(apriori2.java:532) at org.apache.hadoop.mapreduce.Reducer.run(Reducer.java:171) at org.apache.hadoop.mapred.Task$NewCombinerRunner.combine(Task.java:1651) at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.sortAndSpill(MapTask.java:1611) at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.flush(MapTask.java:1462) at org.apache.hadoop.mapred.MapTask$NewOutputCollector.close(MapTask.java:700) at org.apache.hadoop.mapred.MapTask.closeQuietly(MapTask.java:1990) at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:774) at org.apache.hadoop.mapred.MapTask.run(MapTask.java:340) at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:168) 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:1614) at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:163)
先生,非常感谢您的帮助。
最佳答案
使用Yarn,您需要为MapReduce作业的类路径设置“ yarn.application.classpath ”属性。 “导出HADOOP_CLASSPATH”不适用于Yarn。
关于apache - NoClassDefFoundError HBase与YARN,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/29868039/