Is it possible for the same workflow to be executed in parallel by propeller? It seems possible since workflow update handler will just enqueue workflows when an update happens. I suppose one of the writes to etcd would be ignored during the race but it still seems like propeller could progress the same workflow twice with same state? As long as plugins are idempotent this should be ok?

Nope this is not ok

I thought it could happen if there is a streak no? What stops the update handler form being called from 8 writes in a row and the queue handing those off to one of the many workers?

One leader implies one single thread per workflow

Oh ok, I’ll have to take a deeper look at the queue implementation

Yea

Ah ok cool. I realize the streaks are done on a single thread. Was just saying that they theoretically would create n additions to the queue.

Streaks do not add to the queue

I thought the workflow CRD update handler is what adds to the queue? And the streaks keep updating the workflow CRD?

The streak short circuits the flow

https://github.com/flyteorg/flyte/blob/master/flytepropeller/pkg/controller/handler.go#L379 ?