hey,
It is the case that different IOs will be created that connect to the same data stores - HadoopInputFormat in particular uses ES and cassandra, which are also used in their respective IOs as well. Jdbc is likely to have the same type of overlap. This came up while reviewing https://github.com/apache/beam/pull/2177 so I wanted to call this out. I wrote up a quick discussion of a plan for a shared module for those resources here: https://issues.apache.org/jira/browse/BEAM-1644 S
