Upgrading to Elasticsearch 5.0
Elasticsearch 5 version will be released soon. It's a good idea to start testing your cluster's compatibility with the new version. To help with the upgrade process, Elastic.co offers a tool called the Elasticsearch Migration Helper. Install this tool as an Elasticsearch 2.3 plugin:
sudo /usr/share/elasticsearch/bin/plugin install https://github.com/elastic/elasticsearch-migration/releases/download/v2.0-alpha2/elasticsearch-migration-2.0-alpha2.zip
The Elasticsearch Migration Helper is only compatible with Elasticsearch 2.3.
After installing the plugin, open it in the browser by visiting
http://elasticsearch-node-01:9200/_plugin/elasticsearch-migration/, as seen in the following screenshot: