Question

我正在使用HDP 2.0 - hadoop 2.2.0和Apache Avro 1.7.4以及关于新M / R api的followig avro mapreduce指南here

我收到以下错误

2014-07-15 05:46:04,354 FATAL [main] org.apache.hadoop.mapred.YarnChild: Error running child : java.lang.IncompatibleClassChangeError: Found interface org.apache.hadoop.mapreduce.TaskAttemptContext, but class was expected
    at org.apache.avro.mapreduce.AvroKeyInputFormat.createRecordReader(AvroKeyInputFormat.java:47)
    at org.apache.hadoop.mapred.MapTask$NewTrackingRecordReader.<init>(MapTask.java:491)
    at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:734)
    at org.apache.hadoop.mapred.MapTask.run(MapTask.java:339)
    at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:162)
    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:1491)
    at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:157)

似乎我正在混合旧的和新的api。有什么猜测？ THX

Answer 1

实际上找到了问题的解决方案。官方报道here

简单的解决方案 - avro需要针对hadoop 2进行编译

<dependency>
    <groupId>org.apache.avro</groupId>
    <artifactId>avro-mapred</artifactId>
    <version>1.7.4</version>
    <classifier>hadoop2</classifier>
</dependency>

Answer 2

对我来说，我通过将classifier:"hapdoop2"添加到build.gradle文件来解决了这个问题：

 avro_mapred  : [group:"org.apache.avro", name:"avro-mapred", version:"1.7.7", classifier:"hadoop2"],

Avro mapreduce作业失败java.lang.IncompatibleClassChangeError

2 个答案: