Tremor is an event processing engine written in Rust, originally built at Wayfair to sit between their applications and their observability and messaging backends. It was donated to the CNCF and is designed for the kind of high-volume routing, filtering, rate-limiting, and transformation work that otherwise ends up scattered across Logstash, Vector, and custom Kafka consumers.
Pipelines in Tremor are expressed as directed graphs with connectors (onramps and offramps) for things like Kafka, NATS, HTTP, Elasticsearch, and the file system. The logic inside a pipeline is written in Tremor’s own query and scripting languages, which include structural pattern matching over JSON-like records and a SQL-style windowed query language for aggregations.
Tremor’s CNCF matrix status is now archived and the project is effectively dormant, but its ideas around typed event pipelines in Rust live on in tools like Vector and Benthos.