Hi folks, is there a way to trigger a flow B to run if flow A fails, without having a “meta” flow C that waits on flow A to finish ?

Hey @Marwan Sarieddine, I think the best way to do this without a parent flow is to have a StartFlowRun task at the end of your Flow_A that has an

any_failed

trigger for any/some of the upstream tasks. You’ll probably need to find the right trigger that fits best with your use case here, as this Task will be a part of your flow and won’t look to the final state of Flow_A as a trigger, but some set of tasks instead.

Hi @Kyle Moon-Wright - thanks for the quick response, perhaps I should shed some more light on why I am asking: I know I can make use of the

any_failed

trigger to run a task (in case there are upstream failures), and this will correctly capture task run failures throughout the flow, but the edge case I am concerned about is the flow run failing due to underlying infrastructure failures - in which case the downstream trigger task might never get reached

Gotcha, that makes sense and in that case we’d definitely want to capture the failed flow state from the first flow. The only other option I can think of is configuring a Flow Level State Handler that calls out to the backend API with the

create_flow_run

mutation upon a failure at the flow level, which is basically what StartFlowRun is doing anyway in the form of a task. This way you can capture the flow level failure, but as a consequence you won’t get the features/visibility of a Task object. Other than that, I can’t think of a way to accommodate this edge case…. That is, until we unveil the API Actions that you can implement as a part of Prefect Cloud, but SHHH I probably shouldn’t be talking about that yet. prefect duck

Interesting, I’ll take a look at flow-level state handlers - thanks for suggesting that. I am looking forward to see the API Actions released 🙂 !