We'd love to share our work with you: Restate, a system for workflows-as-code (durable execution). With SDKs in JS/Java/Kotlin and a lightweight runtime built in Rust/Tokio.

https://github.com/restatedev/ https://restate.dev/

It is free and open, SDKs are MIT-licensed, runtime permissive BSL (basically just the minimal Amazon defense). We worked on that for a bit over a year. A few points I think are worth mentioning:

- Restate's runtime is a single binary, self-contained, no dependencies aside from a durable disk. It contains basically a lightweight integrated version of a durable log, workflow state machine, state storage, etc. That makes it very compact and easy to run both on a laptop and a server.

- Restate implements durable execution not only for workflows, but the core building block is durable RPC handlers (or event handler). It adds a few concepts on top of durable execution, like virtual objects (turn RPC handlers into virtual actors), durable communication, and durable promises. Here are more details: https://restate.dev/programming-model

- Core design goal for APIs was to keep a familiar style. An app developer should look at Restate examples and say "hey, that looks quite familiar". You can let us know if that worked out.

- Basically every operation (handler invocation, step, ...) goes through a consensus layer, for a high degree of resilience and consistency.

- The lightweight log-centric architecture gives Restate still good latencies: For example around 50ms roundtrip (invoke to result) for a 3-step durable workflow handler (Restate on EBS with fsync for every step).

We'd love to hear what you think of it!

user:	dovys
created:	February 8, 2016
karma:	19