Opensearch ( successor of AWS ElasticSearch ) is a fully managed, highly available, petabyte scale, service to search, visualise, analyse text and unstructured data.

It is based on open-source Elasticsearch, supports SQL queries, integrates with open-source tools and can scale by adding or removing EC2 instances (not a serverless service).

Encryption at rest and in transit.

Availability in up to 3 AZ and backups with snapshots.

Clusters are also know as OpenSearch Service domains.

Opensearch

Data populating the clusters can be ingested by different sources like Kinesis Firehoses, ElasticSearch API, LogStash, then you can use Kibana (or other tools ) to search and visualise data.

Access control is managed in the following ways:

Resource-based polices (aka domain access policies)

Identity-based policies attached to users or roles

IP-based policies - restrict access to one or more IP or CIDR blocks - can't be used with Opensearch clusters within a VPC

Fine-grained - for role-based access control, security at the index, document and field level, and dashboard multitenancy

Authentication via Federation using SAML to on-prem directories and via AWS Cognito and social identity providers.