OpenSearch is a fork of Elasticsearch that is maintained by Amazon. It is a drop-in replacement for Elasticsearch, and is fully compatible with the Elasticsearch API. It is a community-driven project that is open source and free to use.
OpenSearch is a distributed, RESTful search and analytics engine capable of solving a growing number of use cases. It is a good choice for storing data that is not relational in nature.
NAIS offers OpenSearch via Aiven. Aiven OpenSearch can be used by applications in all environments, but must be defined in a GCP cluster.