Is there a Java API for reading the contents of an Elasticsearch index that has been dumped to disk with the 2.X backup tools? We'd prefer to not set up a 2.X cluster and do rolling upgrades and unfortunately, the folks in our organization who are responsible for this data won't send it to us in any other form than a raw dump of their cluster. I've poked around with the Lucene APIs, and I can't seem to get Lucene to read the data.
Can you explain, what the 2.x backup tools are?
Apart from that, have you considered reindex from remote?