Include HttpClient 5.X for the rest client

[AhmadMS1988]

I would like to see HttpClient 5.X included in the next release of the java client.
I has a great potential to solve this issue, and it is already merged in main here and here.
Is there anything preventing this from being included in the next version of the java client as it is one year old?
Thank you very much

[tlfeng]

Hi @AhmadMS1988 Are you requesting to have HttpClient 5.x in next release of Java high-level REST client?
It is embedded in this repository and releases along with OpenSearch core. As your referred PR says, it is considered as a breaking change, so it can only be released along with next OpenSearch major version (3.0).
@reta Could you double check your code change 4833e08 of using HttpClient 5.x is a breaking change that can't be backported to 2.x branch?

I also noticed Java high-level REST client is deprecated, it's recommended switching to the Java client instead. The new "Java client" already have HttpClient 5.x in the code https://github.com/opensearch-project/opensearch-java/tree/v2.6.0/java-client/src/main/java/org/opensearch/client/transport/httpclient5 since version 2.2.0 .

[reta]

Thanks @tlfeng, @AhmadMS1988

Hi @AhmadMS1988 Are you requesting to have HttpClient 5.x in next release of Java high-level REST client?

The Apache HttpClient 5 based RestClient is part of the 3.0.0 release. However, if you switch to officially recommended opensearch-java client, you could benefit of Apache HttpClient 5 right now [1], as @tlfeng mentioned.

@reta Could you double check your code change 4833e08 of using HttpClient 5.x is a breaking change that can't be backported to 2.x branch?

Yes, sadly RestClient leaked Apache HttpClient 4.x APIs (like HttpHost etc) and this is a breaking change both from API and dependency perspectives.

[1] https://github.com/opensearch-project/opensearch-java/blob/2.x/USER_GUIDE.md#create-a-client-using-apachehttpclient5transport