Use UpdateDomainConfig com um AWS SDK ou CLI

import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.opensearch.OpenSearchClient;
import software.amazon.awssdk.services.opensearch.model.ClusterConfig;
import software.amazon.awssdk.services.opensearch.model.OpenSearchException;
import software.amazon.awssdk.services.opensearch.model.UpdateDomainConfigRequest;
import software.amazon.awssdk.services.opensearch.model.UpdateDomainConfigResponse;

/**
 * Before running this Java V2 code example, set up your development
 * environment, including your credentials.
 *
 * For more information, see the following documentation topic:
 *
 * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
 */
public class UpdateDomain {
    public static void main(String[] args) {
        final String usage = """

                Usage:
                    <domainName>

                Where:
                    domainName - The name of the domain to update.

                """;

        if (args.length != 1) {
            System.out.println(usage);
            System.exit(1);
        }

        String domainName = args[0];
        Region region = Region.US_EAST_1;
        OpenSearchClient searchClient = OpenSearchClient.builder()
                .region(region)
                .build();

        updateSpecificDomain(searchClient, domainName);
        System.out.println("Done");
    }

    public static void updateSpecificDomain(OpenSearchClient searchClient, String domainName) {
        try {
            ClusterConfig clusterConfig = ClusterConfig.builder()
                    .instanceCount(3)
                    .build();

            UpdateDomainConfigRequest updateDomainConfigRequest = UpdateDomainConfigRequest.builder()
                    .domainName(domainName)
                    .clusterConfig(clusterConfig)
                    .build();

            System.out.println("Sending domain update request...");
            UpdateDomainConfigResponse updateResponse = searchClient.updateDomainConfig(updateDomainConfigRequest);
            System.out.println("Domain update response from Amazon OpenSearch Service:");
            System.out.println(updateResponse.toString());

        } catch (OpenSearchException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }
}

suspend fun updateSpecificDomain(domainNameVal: String?) {
    val clusterConfigOb =
        ClusterConfig {
            instanceCount = 3
        }

    val request =
        UpdateDomainConfigRequest {
            domainName = domainNameVal
            clusterConfig = clusterConfigOb
        }

    println("Sending domain update request...")
    OpenSearchClient { region = "us-east-1" }.use { searchClient ->
        val updateResponse = searchClient.updateDomainConfig(request)
        println("Domain update response from Amazon OpenSearch Service:")
        println(updateResponse.toString())
    }
}