我试图通过scala实现一个简单的mapreduce作业。但是,当我使用命令运行包时,
hadoop jar hadoop.jar mapreduce.MaxTemperature hdfs://sandbox/user/ajay/input hdfs://sandbox/user/ajay/output
我得到了错误,
16/09/06 16:06:12 INFO mapreduce.Job: Task Id : attempt_1473177830264_0002_m_000001_2, Status : FAILED Error: java.lang.ClassNotFoundException: scala.Predef$
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
at mapreduce.MaxTemperatureMapper.map(MaxTemperatureMapper.scala:17)
at mapreduce.MaxTemperatureMapper.map(MaxTemperatureMapper.scala:9)
at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:146)
at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:787)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:341)
at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:164)
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:1657)
at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:158)
尽管我已经将scala库添加到了我的类路径中,但是我得到了上面的错误。
hadoop版本:hadoop 2.7.1.2.3.0.0-255 scala版本:2.11.8 java版本1.7.0\u 85
任何建议都将不胜感激。
1条答案
按热度按时间5uzkadbs1#
除了将scala库添加到客户机的类路径之外,还必须将它添加到执行任务的所有节点。这可以通过使用toolrunner来实现
hadoop jar scala-2.11/hadoop_2.11-0.1.0.jar mapreduce.WordCount -libjars /usr/lib/scala-2.11.8/lib/scala-library.jar