what's the use of correlation, is there an example explain it?

[elim19]

In spec, it says define event correlation rules. how could I use it in actual cases?
In examples, I do see cases using correlation, but not get what it tries to do, for example, in https://github.com/serverlessworkflow/specification/tree/main/examples#monitor-patient-vital-signs-example, what is the point defining "contextAttributeName": "patientId" in events?
Is it to pass to argument or used in DataFilter?

[tsurdilo]

its the correlation based on some event context attribute. use case is lets say you create a workflow exec per patient
any updates for a specific patient should be associated/correlated to the workflow instance that is associated with that patient id.

[elim19]

https://github.com/serverlessworkflow/specification/blob/main/specification.md#correlation-definition

@tsurdilo I see, so the correlation are just mark some relationship, is there any actual usage, like limit the number of instances with the same correlation contextAttributeValue?

[tsurdilo]

no, rate limiting is not part of event correlation

[cdavernas]

What it allows you to do is being able to correlate the event based on selected attribute to other consumed events that have the same key in said attributes. At least that's what we used it for on Synapse. Check the latest SW workshop about Synapse for a practical example

[elim19]

What it allows you to do is being able to correlate the event based on selected attribute to other consumed events that have the same key in said attributes. At least that's what we used it for on Synapse. Check the latest SW workshop about Synapse for a practical example

@caniszczyk could you give me the practical example link, unable to find it?

[cdavernas]

@elim19 I guess you meant to tag me instead of Cris 🤣? If so, here's the link:
https://www.youtube.com/watch?v=QSqb8cYBVpg&t=54s&ab_channel=CNCFServerlessWorkflow