Hadoop 作业在 FBUtilities.java 中抛出 NullPointerException

Question

我在尝试通过访问 Cassandra 来启动我的 hadoop 作业时收到 NullPointerException。这是堆栈跟踪：

 Exception in thread "main" java.lang.NullPointerException
        at org.apache.cassandra.utils.FBUtilities.newPartitioner(FBUtilities.java:415)
        at org.apache.cassandra.hadoop.ConfigHelper.getOutputPartitioner(ConfigHelper.java:416)
        at org.apache.cassandra.hadoop.ColumnFamilyOutputFormat.checkOutputSpecs(ColumnFamilyOutputFormat.java:90)
        at org.apache.cassandra.hadoop.ColumnFamilyOutputFormat.checkOutputSpecs(ColumnFamilyOutputFormat.java:81)
        at org.apache.hadoop.mapred.JobClient$2.run(JobClient.java:887)
        at org.apache.hadoop.mapred.JobClient$2.run(JobClient.java:850)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAs(Subject.java:416)
        at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1121)
        at org.apache.hadoop.mapred.JobClient.submitJobInternal(JobClient.java:850)
        at org.apache.hadoop.mapreduce.Job.submit(Job.java:500)
        at org.apache.hadoop.mapreduce.Job.waitForCompletion(Job.java:530)
        at RowKeyIndexer.run(RowKeyIndexer.java:393)
        at Indexer.run(Indexer.java:56)
        at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65)
        at Indexer.main(Indexer.java:30)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:616)
        at org.apache.hadoop.util.RunJar.main(RunJar.java:156)

我正在运行 hadoop 版本 1.0.3 和 cassandra 版本 1.1.2。

非常感谢任何帮助，因为我不知道从哪里开始。

非常感谢！

Answer 1

看起来你还没有设置你的输出分区器，像这样：

ConfigHelper.setOutputPartitioner(conf, "org.apache.cassandra.dht.RandomPartitioner");