Having a doubt about PGA and Priority Groups on the pool members. As per the documentation you have to use the 2 together:
"This setting is used in tandem with the pool feature known as priority group activation. You use the priority group activation feature to configure the minimum number of members that must be available before the BIG-IP system begins directing traffic to members in a lower priority group."
So if I configure the pool members with their respective priority group but do not set a "less than" for the PGA, that means that the priority on the members will not take effect and the requests will be balanced in a round-robin fashion if that is the load balance method configured?
If you leave Priority Group Activation to disabled but give a number to a pool member for Priority Activation Group, the feature is still disabled and I don't think anything will happen but whatever you've chosen for your load balancing method.
Yes, pool members' Priority Group value is completely ignored if Priority Group Activation is set to Disabled.