Using XState for implementing a server-side order workflow

[KevinGaudin]

Hi,

I'm looking for some TypeScript libraries that would help implementing a server-side order management workflow in a nodejs server application.

XState seems to be popular in the Node community but most use cases seem to be about UX implementation.

Is XState appropriate for handling persisted objects in a DB and make them follow the state-machine workflow based on external events and trigger external actions ?

Thanks for your insights !
Kevin

[davidkpiano]

Is XState appropriate for handling persisted objects in a DB and make them follow the state-machine workflow based on external events and trigger external actions?

Yes! Check out this example using Azure Durable Entities with XState in a stateful, serverless environment: https://github.com/davidkpiano/durable-entities-xstate

[hmvs]

Hey @markwallsgrove have you found anything that matches your use case? I have a similar use case and looking for library that could help me with that.

[markwallsgrove]

👋 @hmvs. Sadly I didn't find a conclusion to this investigation. My best guess would be to use AWS SQS FIFO queues where the message group id is set to something like ${objectType}:${objectId}. The queue could then be processed with a AWS Lambda function, which is where XState would be used.

[hmvs]

I see. Thanks, I thought you might have found another library.

[markwallsgrove]

The crooks of my argument Having a queue per mortgage agreement seems incredibly expensive from a management and cost point of view. isn't true if the AWS SQS FIFO is used with a message group id.

Waiting for a response is complicated though (when it's required). Currently others have used the approach of creating a new SQS queue with a predictable name & adding a new item to that queue once the request has been processed. Amazon has created a temporary queue mechanism, but it's only available in Java :(.

[gaffarmalik]

A good idea here is to stick to your database.
Have some worker pick jobs from the db.
Lock a row that's currently in use by some other wrkflow instance and enjoy your day.