An OpenSearch Service domain is synonymous with an OpenSearch cluster.
Domains are clusters with specified settings, instance types, instance counts, and storage resources.
automates common administrative tasks, such as performing backups, monitoring instances and patching software once the domain is running.
uses a blue/green deployment process when updating domains. Blue/green typically refers to the practice of running two production environments, one live and one idle, and switching the two as software changes are made.
All domains configured for multiple AZs have zone awareness enabled to ensure shards are distributed across AZs.
OpenSearch Service domains support encryption at rest through AWS Key Management Service (KMS), node-to-node encryption over TLS, and the ability to require clients to communicate with HTTPS.
supports only symmetric encryption KMS keys, not asymmetric ones.
encrypts all indices, log files, swap files, and automated snapshots.
does not encrypt Manual snapshots and slow & error logs.
can be configured to be accessible with an endpoint within the VPC or a public endpoint accessible to the internet.
Network access for VPC endpoints is controlled by security groups and for public endpoints, access can be granted or restricted by IP address.
supports integration with Cognito, to allow the end-users to log-in to OpenSearch dashboards through enterprise identity providers such as Microsoft Active Directory using SAML 2.0, Cognito User Pools, and more.
OpenSearch Storage Tiers
OpenSearch Service supports three integrated storage tiers, Hot, UltraWarm and Cold.
Hot tier is powered by data nodes which are used for indexing, updating, and providing the fastest access to data.
UltraWarm nodes complement the hot tier by providing a fully managed, low-cost, read-only, warm storage tier for older and less-frequently accessed data.
UltraWarm uses S3 for storage and removes the need to configure a replica for the warm data.
Cold storage is a fully-managed lowest cost storage tier that makes it easy to securely store and analyze the historical logs on-demand.
Cold storage helps fully detach storage from compute when they are not actively performing analysis of their data and keep the data readily available at low cost.
OpenSearch Cross-Cluster Replication
Cross-cluster replication helps automate copying and synchronizing indices from one cluster to another at low latency in the same or different AWS Regions.
Domains participating in cross-cluster replications need to meet the following criteria:
Participating domains should be on Elasticsearch version 7.10
Participating domains need to have encryption in transit enabled
Participating domains need to have Fine-Grained Access Control (FGAC) enabled
Participating domains versions should adhere to the same rules as rolling version upgrade
Current implementation of cross-cluster replication does not support Ultrawarm or Cold Storage.
AWS Certification Exam Practice Questions
Questions are collected from Internet and the answers are marked as per my knowledge and understanding (which might differ with yours).
AWS services are updated everyday and both the answers and questions might be outdated soon, so research accordingly.
AWS exam questions are not updated to keep up the pace with AWS updates, so even if the underlying feature has changed the question might not be updated
Open to further feedback, discussion and correction.