Amazon OpenSearch Service now lets you update node count without blue/green

[Amazon OpenSearch Service](https://docs.aws.amazon.com/opensearch-service/latest/developerguide/createupdatedomains.html) is now extending the ability to update the number of data nodes without requiring a blue/green deployment for clusters without dedicated cluster manager (master) nodes. This change will allow you to make node count changes faster. Clusters with dedicated cluster manager nodes already supported updating the data node count without a blue/green deployment. Previously, when you updated the data nodes instance count on your domain without dedicated cluster manager, OpenSearch Service used a blue/green deployment mechanism to make the change. While blue/green deployments are meant to avoid any disruption to your clusters, as the deployment utilizes additional resources on the domain, it is recommended that you perform them during low traffic periods. Now, you can update number of data nodes without requiring a blue/green deployment, ensuring that these updates can complete faster, while avoiding any potential disruption to your cluster operations. In cases wherein you modify both data node instance type and count, OpenSearch Service will still use a blue/green deployment. You can use the [dry-run](https://docs.aws.amazon.com/opensearch-service/latest/developerguide/managedomains-configuration-changes.html#dryrun) option to check whether your change requires a blue/green deployment. The improved experience is available for domains running any OpenSearch version, and Elasticsearch versions 7.1 and above supported on the service. The new feature is available in all AWS Regions where Amazon OpenSearch Service is available. Please refer to the [AWS Region Table](https://aws.amazon.com/about-aws/global-infrastructure/regional-product-services/) for more information about Amazon OpenSearch Service availability. For more information regarding making configuration changes in Amazon OpenSearch Service, please see the [documentation](https://docs.aws.amazon.com/opensearch-service/latest/developerguide/managedomains-configuration-changes.html). To learn more about Amazon OpenSearch Service, please visit the [product page](https://aws.amazon.com/opensearch-service/).