Amazon OpenSearch Service now offers customers the option to provision a dedicated coordinator node. Dedicated coordinator nodes relieve data nodes from the responsibilities of traffic coordination and hosting of OpenSearch Dashboards, enabling better resource utilization, and improving overall efficiency of the cluster. In addition, coordinator nodes help reduce the number of private IP addresses that need to be reserved for virtual private cloud (VPC) domains.
In the absence of a dedicated coordinator node, data nodes perform coordination role alongside their core responsibilities of search, data storage, and indexing. Data nodes also host OpenSearch dashboards. When performing multiple roles, in some scenarios, data nodes may face increased pressure on memory and CPU resources. Provisioning dedicated coordinator nodes helps in offloading traffic coordination, and dashboard hosting responsibilities from data nodes, which can improve the overall resiliency of the cluster. In addition, with dedicated coordinator nodes, OpenSearch VPC domains attach elastic network interfaces (ENI) to these nodes instead of data nodes. Dedicated coordinator nodes usually represent around 10% of the total data nodes. As a result, you require a significantly smaller number of private IP addresses for VPC domains.
All OpenSearch versions, and Elasticsearch (open source) versions from 6.8 through 7.10 support the provisioning of a dedicated coordinator node. It is available in all AWS Commercial and the AWS GovCloud (US) Regions where OpenSearch Service is available. See here for a full listing of our regions.
To learn more about configuring a dedicated coordinator node in your cluster, please refer to the documentation.
Source:: Amazon AWS