We currently build all of ORC with Hadoop 2.6. Our shims let us run with older versions back to Hadoop 2.2. However, it is easy to mess up and use Hadoop 2.6 features in core. Therefore, I propose:
- We create a shim module that compiles with Hadoop 2.6 and move HadoopShims and HadoopShimsCurrent into it.
- We build core and mapreduce with Hadoop 2.2.
- Tools & bench will continue to use Hadoop 2.6.