how to upgrade elasticsearch from 2.4 to 5.6?
i have read https://www.elastic.co/guide/en/elasticsearch/reference/5.6/rolling-upgrades.html
but what step actually i need to do? this is not very clear.
i already backup the data from 2.4.
after diasabled shard, and syns, i it direct can reindex?
but how to migrate the data from 2.4 to 5.6?