Unable to Connect to Server from Spring boot application in es 8.12

[Aditya_Teltia]

While I am able to connect for version es 7.17 but when I am doing the same for version 8.x I am unable to connect.

I have to connect to 8.x since I want to use KNN query which it seems is only available in 8.x and later versions.

Below is my Elasticsearch Config file while I am connecting to 7.17. What needs to be fixed or added in this so that I am able to connect to 8.x version since there is a requirement of username, password and ca_cert in that

package com.similarity.match.config;

import org.apache.http.HttpHost;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class ElasticsearchConfig {

    @Value("${elasticsearch.host}")
    private String host;

    @Value("${elasticsearch.port}")
    private int port;

    @Value("${elasticsearch.scheme}")
    private String scheme;

    @Bean(destroyMethod = "close")
    public RestHighLevelClient restHighLevelClient() {

        return new RestHighLevelClient(
                RestClient.builder(
                        new HttpHost(host, port, scheme)
                ).setHttpClientConfigCallback(httpAsyncClientBuilder ->
                        httpAsyncClientBuilder));
    }
}

Also how can I write a knn query using Java RestHighLevelClient. Wasn't able to find any resource for the same online.

[Sunile_Manjee]

@Aditya_Teltia

RestHighLevelClient

Have you considered migrating from RHLC to ES java API? Migrating from the High Level Rest Client | Elasticsearch Java API Client [8.12] | Elastic

[Aditya_Teltia]

I tried doing the same but I getting that it is abstract and cannot be instantiated. But in the documentation it is done the way I have instantiated it.