Java Rest High Level Client Support for Elastic 5.5 and 6.x

Elastic Stack Elasticsearch
1

Currently we developed our application based on Elastic 6.2.1 version, however client wants to use our code against Elastic 5.5.

Our application is java based, where we are using Java Rest High Level Client to connect to Elastic.

We are majorly using the Java REST High level client for creating indexes, inserting/updating/deleting/Querying documents from elastic.

The question i have is will Java REST high level client which was introduced in 6.x of elastic support queries against Elastic 5.5 ?

If No - What are alternatives you suggest ?
If yes - Do we need to make any code changes to call Elastic 5.5 ?

2

Sadly not all queries are compatible. So it depends.

For example the TermQuery works well IIRC against a 5.x and 6.x cluster.
But as the doc says the 6.x HLClient works only with 6.x clusters: https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-high-compatibility.html

You can use for some queries the LowLevel client but you need to reimplement the response parsing logic I think.

3

Thanks David for quick Response.