I had MySQL running on some bare metal for many years without a restart.
I was terrified to update the kernel at that point, knowing that system disk had been running continuously for many years, and had no faith it would restart successfully.
Finally got two new servers to replace these (with these new SSD things!) and after migration, sure enough, one of the old servers failed to boot.
Even if your mysql instance and hardware had run indefinitely, if a table is being written to it will eventually run out of disk space or key space and crash. How long it will take depends on the application but it will happen eventually and if no one is around to fix it...
I was terrified to update the kernel at that point, knowing that system disk had been running continuously for many years, and had no faith it would restart successfully.
Finally got two new servers to replace these (with these new SSD things!) and after migration, sure enough, one of the old servers failed to boot.