[Bug] [master] Infinite Retry Loop When Pausing a Workflow with Pending TaskGroup Tasks

[eye-gu]

Search before asking

• I had searched in the issues and found no similar issues.

What happened

When a workflow is paused while it contains tasks waiting for a TaskGroup slot, those tasks enter an infinite pause-retry loop. The task state remains SUBMITTED_SUCCESS, the workflow state remains READY_PAUSE, and neither can ever progress.

What you expected to happen

The task should be paused, releasing its TaskGroup queue slot. The workflow should reach the PAUSE state.

How to reproduce

1. Create a workflow containing a task that uses a TaskGroup
2. Start the workflow → the task enters SUBMITTED_SUCCESS and waits for the TaskGroup slot
3. Immediately pause the workflow

Anything else

A simple approach is to add a check in TaskSubmittedStateAction#onPauseEvent: if the task is waiting for a TaskGroup slot, the Paused event can also be triggered directly.

A better approach would be to introduce a dedicated WAITING_TASK_GROUP status. This would not only simplify the pause event handling, but also allow users to see the real workflow state on the UI.

Version

dev

Are you willing to submit PR?

• Yes I am willing to submit a PR!

Code of Conduct

• I agree to follow this project's Code of Conduct

[eye-gu]

@SbloodyS Do you think it's better to quickly fix bugs first, or to add a new task state?

[SbloodyS]

cc @ruanwenjun

[SbloodyS]

I have a quick understanding of this design logic. This is because the task is waiting for taskGroup resources. For non-running tasks, we will keep trying to pause/kill them. Once resources become available, the task will enter the dispatch/running stage, and then it can be paused/killed. The logic of this block can be optimized. It is not a bug, so I mark it as improvement.

[eye-gu]

@SbloodyS Even when the TaskGroup slot becomes available, the task will remain SUBMITTED_SUCCESS forever and the workflow will remain READY_PAUSE forever. This is because notifyWaitingTaskInstance rejects notification when the workflow is not in RUNNING_EXECUTION state. So this is actually a bug, not just an improvement.

[SbloodyS]

I got what you mean. I mark this issue back to the bug and open a new improvement issue.