Setup new Elasticsearch
For the new version Phrase On-Premise the required Elasticsearch version has changed. Before you can upgrade Phrase On-Premise from Version 2 to 3 you have to Setup Elasticsearch >= 6.0.1. A new index will be generated automatically.
Change Elasticsearch URL environment variable
Also the environment variable naming has changed from
ELASTICSEARCH_URL. So before upgrading you have to change the name and set this to your new Elasticsearch host adresse.
Follow the normal update flow