Here is the scheduler_default_filters setting I am using my /etc/nova/nova.conf. I think some of these settings are obsolete/deprecated in Juno ...
scheduler_default_filters = AggregateInstanceExtraSpecsFilter,AvailabilityZoneFilter,RamFilter,ComputeFilter,CoreFilter,DifferentHostFilter,SameHostFilter,GroupAntiAffinityFilter,AggregateCoreFilter,AggregateRamFilter,AggregateTypeAffinityFilter
... but I am not sure where to find the definitive listing of current and deprecated nova settings.