We got 400 LoC StepFunctions to 40 LoC TypeScript by making Lambdas suspendable

https://restate.dev/blog/we-replaced-400-lines-of-stepfunctions-asl-with-40-lines-of-typescript-by-making-lambdas-suspendable/

by p10jkle • 3 years ago

12 4 3 years ago

restate.dev

JackHopkins2• 3 years ago

This is really cool! Am I right in thinking that the cost for running this program is equivalent to all of the dependency execution durations? i.e no busy waiting?

p10jkle• 3 years ago

yep no busy waiting for calls and sleeps within the system. However, 'sideEffects' where you basically just commit the result of an external operation still block the Lambda. But we're thinking about exposing a `fetch` api directly from the runtime (ie, we do a call on your behalf) that could in theory sort that out

sewen• 3 years ago

To a first approximation, yes. There is some small cost for the workflow function itself, but as this doesn't wait on responses and only really executes the side effects, it is not that much. Especially, given that this has comparable semantics to the accurate mode (not the express mode) of StepFunctions (which is charged by number of state transitions and not super cheap).

JackHopkins2• 3 years ago

What is the order of the cost of the workflow function?

We got 400 LoC StepFunctions to 40 LoC TypeScript by making Lambdas suspendable

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