Bases: nova.scheduler.filters.BaseHostFilter
TypeAffinityFilter doesn’t allow more then one VM type per host.
Note: this works best with compute_fill_first_cost_fn_weight (dispersion) set to 1 (-1 by default).
Dynamically limits hosts to one instance type
Return False if host has any instance types other then the requested type. Return True if all instance types match or if host is empty.