DynamoDB Local vs MockServer

DynamoDB Local lets developers develop and test applications without accessing the DynamoDB web service. It can run without an internet connection, and AWS says local use can help avoid throughput, storage and data-transfer fees. Developers can obtain it as a download, Apache Maven dependency or Docker image, and AWS documents use with the AWS CLI, AWS SDKs, Docker Compose, Maven and AWS CloudShell. Data can persist in a local database file or remain in memory, where it is lost when DynamoDB Local stops. The downloadable version requires configured credentials, though AWS says they need not be valid AWS credentials for local access. AWS identifies v3.x as current and recommends it for local testing and development; v2.x is legacy and v1.x is deprecated. Running v2.6.0 or later requires JRE 17.x or newer. Telemetry can be disabled with a command-line option or environment settings. DynamoDB Local does not support point-in-time recovery, tagging or vector indexes; it also lacks parallel scans, ignores provisioned throughput settings and treats table names as case insensitive. AWS describes it as a development and testing tool, not a production service.

MockServer is a free, self-hosted tool for mocking and proxying HTTP, HTTPS, and gRPC services during isolated testing. It can verify requests as well as stand in for services. Teams can generate mocks and validate traffic against OpenAPI or Swagger contracts, or import recorded sessions from browser HAR files and Postman collections. Beyond HTTP services, it can mock gRPC, AsyncAPI brokers such as Kafka, MQTT, and AMQP, and OAuth2/OIDC providers. Its protocol coverage includes HTTP/1.1, HTTP/2, HTTPS, SOCKS, and experimental HTTP/3, which uses a separate UDP port. For fault-oriented testing, it can add latency, errors, dropped connections, and malformed responses to mocked or proxied traffic. Deployment options include Docker, an executable JAR, Helm/Kubernetes, Testcontainers, Homebrew, and a JVM-less bundle. A web dashboard displays logs, expectations, and recorded traffic; Prometheus metrics and OpenTelemetry tracing are available for shared environments. Each instance includes an MCP server at /mockserver/mcp. The /mockserver/status and /mockserver/ready probes remain reachable without authentication or authorization.