Upgrading of Elasticsearch 1.7.3 to 2.3.5

Elastic Stack Elasticsearch
1

Anyone knows the steps to upgrade elasticsearch from 1.7.3 to 2.5.3?

The link below is useless. They either lead to long list of exceptions or the indices will be not appear anymore.

https://www.elastic.co/guide/en/elasticsearch/reference/current/rolling-upgrades.html#upgrade-node

2

Have you read this blog post and run the migration plugin described therein to identify any potential issues that would cause problems in an upgrade?

3

2.5.3 doesn't exist, maybe you mean 2.3.5?

4

Sorry. Wrote the wrong version number. The correct version should be 2.3.5