Though it is more to do with SQL Storage kind of question, I have just dragged into Performance tuning section for the sake of large installation you talk with clustering. For the sake of discussion it seems better to plan ahead for the failing instances since, for example, two of the four servers could...
The system DMV sys.dm_os_schedulers is an useful DMV to find such as running tasks & active workers threads etc. This is required to monitor the system state is heavily loaded or not, in particular this view will help you identify if there is any CPU bottleneck in the SQL Server machine. SELECT scheduler_id...