simple MR examples using basic string serialization with Mapper/ReducerCombiner Base and Mapper/ReducerCombiner Contexts are working fine. however I ran into issues when trying to work with JSON classes. I wrote an MR job as follows:
with JsonMapperContext<MyOut> for the Map-Method and
with JsonReducerCombinerContext<MyOut> for the Reduce-Method
(...of course Mapper-Type MyOut matches ReducerCombiner-Type MyIn)
Running this job from VS2013 on Azure HDInsight 2.1 cluster always fails with the following error/exception for the launched Map-Task(s)
java.lang.RuntimeException: PipeMapRed.waitOutputThreads(): subprocess failed with code 255
and the whole job eventually gets killed. Any ideas what I might be doing wrong here? As I said other non-JSON examples are working...
Unfortunately the samples in the source code are not using JsonInOutXXX
-Base classes, so that doesn't help much.
Thanks for your help.