Using AWS provided Elasticsearch service is costly. Hosting Elasticsearch on an EC2 instance can be cost efficient but requires multiple configurations. This pages details out the setup and configuration steps used for creating a multi-node Elasticsearch on EC2 instance.
Amazon OpenSearch Service is the AWS-managed service that lets you run OpenSearch clusters without having to worry about managing, monitoring, and maintaining your infrastructure, or having to build in-depth expertise in operating OpenSearch clusters. Amazon OpenSearch can be used as the Elasticsearch server for Alfresco Search Enterprise.