Our Sophia Feng has an integration test which executes DDL operations with a new monkey to kill the active master as a high level test for the proc v2 changes.
The test does random DDL operations from 20 client threads. The DDL statements are create / delete / modify / enable / disable table and CF operations. It runs HBCK to verify the end state.
The test can be run on a single master, or multi master setup.