LinkedIn Databus vs Maxwell's Daemon

LinkedIn Databus is a self-hosted, source-agnostic distributed change data capture system. It captures and transports changes to primary data so downstream systems can process them. Relays serve change events, clients process them, and bootstrap servers supply historical events for consumers catching up. Consumers can begin at an arbitrary point in the stream, use full-data bootstrap, and consume partitions while preserving source consistency.

The project describes in-order, at-least-once delivery with high availability, low-millisecond transport latency, and throughput of thousands of events per second per server. It supports Oracle sources and has been used for search and social-graph indexes and member-profile read replicas. The wiki documents a MySQL adapter as a proof of concept, not a LinkedIn production deployment. Databus is free, licensed under Apache 2.0, and available for self-hosting. Building it requires Gradle 1.0 or later and Oracle's ojdbc6 driver version 11.2.0.2.0, which is obtained under the Oracle Technology Network License. The repository points to a wiki for documentation and examples; it does not state a support service.

Maxwell's Daemon is a free, open-source, self-hosted Linux tool for moving MySQL changes into streaming systems. It reads MySQL binary logs and emits database changes as JSON for Kafka, Kinesis, SQS, SNS, NATS, Google Cloud Pub/Sub, BigQuery, RabbitMQ, Redis, and other destinations. Listed uses include ETL, database change auditing, cache building or expiration, search indexing, and communication between services. Filtering can select databases, tables, and column values, while JavaScript filters handle custom row filtering and data changes. When encryption is enabled, messages use AES/CBC/PKCS5PADDING with a user-provided key and base64-encoded values. Metrics can be exposed through logging, JMX, HTTP, or Datadog; HTTP endpoints cover metrics, Prometheus, health checks, ping, and diagnostics. Maxwell supports schema evolution and an initial snapshot. Deployment options include command line, Docker, binary distribution, and Homebrew. Requirements include JRE 11 or later, supported MySQL versions from 5.1 through 8, and Kafka 0.8.2 or later when Kafka is used.