Amazon OpenSearch Service (Amazon Elasticsearch Service successor) is a managed service that simplifies the deployment, operation, and scaling of OpenSearch clusters in AWS Cloud. It was found that the Elasticsearch domain {AwsElasticSearch} is configured with less than three master nodes or has 'DedicatedMasterEnabled' disabled. The master nodes are responsible for managing and orchestrating the cluster and its nodes. An Elasticsearch domain requires at least three master nodes for high availability and fault tolerance in case a node fails.