OpenSearch Domain in "Modifying" State — Is It Still Queryable?

During configuration changes in Amazon OpenSearch Service, your cluster remains available for incoming search and indexing requests. However, there are some performance considerations to be aware of during the update process. You may experience increased search and indexing latency as the service processes the changes, and there could be increased rejections for incoming requests as the cluster load increases.

To minimize potential performance impacts, it's recommended to perform configuration changes when the cluster is healthy and during periods of low network traffic. While the domain is in the "modifying" state, configuration changes such as adding new data nodes, EBS modifications, or other updates are being processed.

For domains undergoing configuration changes, you can monitor the progress through the Domain processing status and Configuration change status fields in the console. The domain will continue processing requests during this time, though you should wait for the domain status to become "Active" before requesting any additional changes.

Reference

[1] https://docs.aws.amazon.com/opensearch-service/latest/developerguide/managedomains-configuration-changes.html