Is there a particular reason that nested SUB_WORKFLOW within a DO_WHILE is not supported?

[pweatherby-ccctc]

The documentation on DO_WHILE tasks clearly states that SUB_WORKFLOW within a DO_WHILE is not supported.

The WorkflowTaskTypeConstraint enforces that DO_WHILE loopOver tasks are not (and do not contain) a SUB_WORKFLOW.

My question is: "Why is not supported?"

Perhaps this has already been answered/documented, but I have searched and cant find reasoning on it.

I am using v2.31.4, but plan to upgrade soon-ish. but it appears that, even at the latest, it's still not supported.

Perhaps it has to do with task domains? or isolation concerns? or... i dunno?
Or perhaps it is a hold-over from a limitation of a previous workflow engine that no longer exists? (and now, we can support it?)

EDIT/Update: I was still searching more for an answer to this question and found: https://github.com/Netflix/conductor/pull/1435/files which was an attempt (that was eventually closed due to inactivity) to add in support. Whats interesting about it (to me at least) is: the code changed is all removing superficial checks/tests that impose the unsupported constraint. I don't see any code that adds functionality per-say. Instead, just removing the code that dis-allows it. Reading the comments on the PR, it looks like everything was good to go, except needing some additional integration tests.

@apanicker-nflx @manan164 Can you confirm any of the above regarding the status of nested sub_workflows within a do_while?

[manan164]

Hi @pweatherby-ccctc , I had created PR to support it. Had to close it since I was not able to find time to write integration tests. Feel free to write and use it.