The Apache Hadoop community has recently released the first alpha version
for Hadoop 3.0.0, while we are still supporting Hadoop 1. I think its time
to finally drop Hadoop 1 support in Flink.
The last minor Hadoop 1 release was in 27 June, 2014.
Apache Spark dropped Hadoop 1 support with their 2.0 release in July 2016.
Hadoop 2.2 was first released in October 2013, so there was enough time for
users to upgrade.
I added also the user@ list to the discussion to get opinions about this
from there as well.
Let me know what you think about this!