More info.

Can someone enlighten me and tell me in what use cases I would use step functions? this might sound dumb but I might not have read about them enough. 😂

I have same question @Kujtim Hoxha

Yeah I was a bit confused by them at first too. They're great for coordinating a workflow of multiple steps. For example if you need to 1. Fetch a list of urls from an endpoint 2. For each item returned, spin up a lambda to fetch the html 3. For each of those count the number of words there are 4. Aggregate to a final count You can coordinate this with step functions so that steps 2+3 are run in massive parallel. Recently they added support for steps that just call an api method on an AWS service

@thdxr so this coordination is on code?

It's using a declarative structure, not exactly like code

But where is that stored?

Yeah you can do it through cdk. We've been trying to think of a good abstraction over it so it feels more like code

Nice.

I use Step functions very often. I use for solve all asyncronous job, in particular I use it more often to: • Run a job when some event happen (for example when an api invocation imply a data elaboration which is not related to the api response, in this scenario I run a state machine on api invocation to perform all task, in this way I can close the http request fast (and I don’t reach 30 seconds limit on. api gateway) • Time Scheduler, using WAIT task is possibile to pause the state machine specifing “seconds to wait” or “timestamp to wait”

@gio Does it cost much?

I use it in the same way, anywhere that I can't guarantee an instant response I kick off a step function instead

@thdxr are there any good abstractions on their way for sst to use step functions

We don't have any great ideas haha. We might start off with something small just to get the custom lambda step feeling less verbose

So when you say

I use it in the same way, anywhere that I can't guarantee an instant response I kick off a step function instead

Do you mean the last step before you return the api call is start a workflow that does behind the scene stuff. My current solution for that is EventBridge and SqS so basically I send an event out and have queues for handling those async things

Yeah it's faster but you don't get the nice retry stuff automatically that you get with sqs

Got it, so basically like everything else it is good for some things 😂

yep lol

Step functions is a cool product but it’s very expensive: • 0.025 USD per 1000 state transaction for Standard workflow (no time execution limit, usable as time scheduler) • 1 USD per 1 milion request for Express workflow (5 minutes max execution time) I never had experience with SQS+Eventbridge, but it could be a cheaper solution as simple time scheduler.

It’s the cloud, who cares about price? 😂

If you are a freelancer of course AWS is a no profit company 😂