For relational workloads, Amazon RDS offers managed engines like PostgreSQL, MySQL, and SQL Server. Multi-AZ deployments provide high availability through a synchronous standby in another Availability Zone, while Read Replicas are asynchronous copies intended to scale reads. Aurora, the AWS-native engine, stores six copies of your data across three AZs automatically and can typically fail over in under 30 seconds. Aurora Serverless v2 scales capacity in fine-grained ACUs in seconds, making it a strong fit for variable or spiky demand. To encrypt an existing unencrypted RDS instance, you cannot flip a switch in place; you take a snapshot, copy it with encryption enabled, and restore.
DynamoDB is the managed NoSQL key-value and document database. On-Demand capacity mode is ideal for bursty or unpredictable traffic because it charges per request with no provisioning required. For queries on non-key attributes, Global Secondary Indexes (GSI) and Local Secondary Indexes (LSI) provide alternate query patterns, and DynamoDB Global Tables deliver multi-region, active-active replication. For globally distributed SQL, Aurora Global Database is the relational counterpart.
ElastiCache sits in front of databases to absorb reads. Memcached is a simple, multi-threaded cache best for ephemeral key-value use, while Redis (now ElastiCache for Redis) adds persistence, replication, pub/sub, and richer data structures. Amazon Redshift is the petabyte-scale columnar data warehouse, and Amazon OpenSearch Service is the managed OpenSearch cluster for full-text and log analytics.
For data lake analytics, Athena runs SQL directly against files in S3 with no cluster to manage, and the AWS Glue Data Catalog plus crawlers keep the schema discoverable. AWS Glue also runs serverless Spark ETL jobs. Kinesis Data Firehose loads streaming data into S3, Redshift, or OpenSearch without writing consumer code, while Kinesis Data Analytics runs Apache Flink stream processing. Managed Kafka is available as Amazon MSK, and managed Airflow as Amazon MWAA for workflow orchestration.