First I would make sure that you are using the correct version of Elastic Search, for Octane 12.55.8 you will need to use elastic search 2.4.0.
Also make sure that you are using port ''9300'' in the ''ElasticPort'' entry in the setup.xml file, port 9200 is only used to ''test'' elasticsearch, in most instances elasticsearch will use port 9300 for communication with octane......
I would also try using Semicolons instead of commas to separate the elastic search hosts in the setup.xml file for Octane. I have seen this fix the issue firsthand. I think that there may be a bug in the documentation where it tells you to use commas as the delimiter, I have reported this to MicroFocus as an issue with the install guide. So instead of:
elastic1.test.com,elastic2.test.com,elastic3.test.com
Try this:
elastic1.test.com;elastic2.test.com;elastic3.test.com
Next I would make sure that you can run the Curl command FROM the Octane server and that it retrieves the elastic search info, so for example you could do ''CURL -xget 'elastic1.test.com:9200' If you don't have curl alternatively from the Octane server try to navigate to http://elastic1.test.com:9200 it should return a json file that should have the node name, version, etc.... Do this check for each one of the elastic nodes...
If you cannot do this then more than likely When you setup elastic search did you edit the network settings in the elasticsearch.yml file? Elasticsearch binds to localhost only by default. This is sufficient for you to run a local development server (or even a development cluster, if you start multiple nodes on the same machine), but you will need to configure some basic network settings in order to run a real production cluster across multiple servers. You may need to setup the network.host parameter in the elasticsearch.yml file.
https://www.elastic.co/guide/en/elasticsearch/reference/2.4/modules-network.html
NOTE: MicroFocus has now fixed the install guides for version 12.55.8 so now the guides should reference using semicolons as the delimiter instead of commas