SharePoint Workflows cannot be stopped in Workflow Manager?

You might notice that (sometimes) workflows which running in endless-loop cannot be stopped. For example, imagine there is a workflow which is running in while(true) loop after is started.

1. Issue 1:

If you try to stop such workflow it will not be stopped for very long time (depending on system load, it can take hours). It seems that some messages used for stop operation are not treaded with high priority.

2. Issue 2:

Sometimes even if the workflow is stopped (it does not appear in instance table and workflow client api does not return it in running state) it will continue to run.
I have activity which continues to trace out some data even if the workflow is stopped.

WORKAROUND: The only possible work around in both cases is to remove the scope which holds that workflow.

- Remove the scope from Scopes table of WFResourceManagementDb database.
- Restart ServiceBus Gateway and Broker services
- Create scope programmatically.
- Publish workflow again.

This will cause all running instances of the workflow to fail!!