hadoop - Sqoop合并问题-Hortonworks

Question

我的合并键属性上确实有一个主键列。任何帮助都深表感谢

16/09/16 14:50:06 INFO mapreduce.Job: Task Id : attempt_1474053990963_0023_m_000000_2, Status : FAILED
Error: java.io.IOException: Cannot join values on null key. Did you specify a key column that exists?
        at org.apache.sqoop.mapreduce.MergeMapperBase.processRecord(MergeMapperBase.java:79)
        at org.apache.sqoop.mapreduce.MergeTextMapper.map(MergeTextMapper.java:58)
        at org.apache.sqoop.mapreduce.MergeTextMapper.map(MergeTextMapper.java:34)
        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:168)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAs(Subject.java:422)
        at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1657)
        at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:162)

Answer 1

终于我找到了解决方案。我正在使用mysql db，表中的主键以小写字母定义，但是对于合并作业，我以大写字母给出了键。这是造成问题的原因。一旦我以小写形式给合并作业中的主键，作业就成功运行了