I am proud to announce that both ES-Hadoop 5.4.1 and 5.3.3 have been released!
Elasticsearch 5.4.1 includes enhancements for the HDFS Repository Plugin to enable secure access to Kerberized HDFS instances in a manner that is compatible with the Elasticsearch's security model. This fixes a long standing regression between 2.x and 5.x.
ES-Hadoop 5.3.3 includes a fix for backwards compatibility towards Elasticsearch clusters in the 1.x line. ES-Hadoop 5.4.1 also includes this fix as well as some fixes for Spark's serialization code, not to mention being tested specifically against the newest Elasticsearch 5.4.1.