Blocker Description
If you have a fresh cluster that is directly connected to via a 4.15+ client, then SYSTEM.MUTEX gets created without a TTL (See this) The SYSTEM.MUTEX DDL does not specify a TTL.
This will obviously be a problem when a client does any operation that requires writing a cell to SYSTEM.MUTEX via checkAndPut (like add/drop column, create view, etc.) and dies/gets disconnected before being able to delete the mutex cell.
After that point, since the cell will stay written and never be TTL’ed, any operation which requires a checkAndPut on that cell will always fail with a ConcurrentTableMutationException, deeming any further add/drop cols or create view for the same name impossible.
