Amazon DynamoDB vs etcd

Amazon DynamoDB is a serverless, managed NoSQL database for applications that need single-digit millisecond performance at any scale, according to AWS. Users do not provision or patch database servers, and tables can scale automatically, including to zero in on-demand mode. Primary keys and global or local secondary indexes provide ways to query data. Global tables support multi-Region, multi-active operation; AWS says they are designed for up to 99.999% availability. The database also supports native vector search for similarity searches and agent memory use cases. Data is encrypted in transit and at rest by default, and IAM policies can restrict access to specific items and attributes. Point-in-time recovery provides continuous, per-second backups and restoration within a configured period of 1 to 35 days. A free tier is listed with 25 WCUs, 25 RCUs, and 25 GB of storage per Region and payer account, among other limits. On-demand capacity is billed per request consumed; provisioned capacity is billed for specified capacity even if usage is lower.

etcd is an open-source, strongly consistent distributed key-value store for data used by distributed systems and clusters of machines. It arranges values in hierarchical directories and lets clients watch keys or directories for changes. Clients can read and write values with standard HTTP tools such as curl, and keys may have optional time-to-live expiration. The project uses the Raft protocol and handles leader elections during network partitions, including when a leader machine fails. etcd is a core Kubernetes component and its primary datastore. The project provides pre-built binaries, source builds, and container images. Linux on AMD64 and ARM64 is tier 1; Darwin and Windows on either architecture are tier 3, and other platforms are unsupported. TLS and client-certificate authentication are supported for client and peer connections, but neither is enabled by default. The software is self-hosted and licensed under Apache 2.0, with a listed price of free. The integrations listing includes Kubernetes, CoreDNS, and language client libraries, while warning that third-party tools and libraries there are not tested or maintained by the etcd team.