+---------------------------------------------+
| +--------+ +--------+ +--------+ |
| | node 1 | | node 2 | | node 3 | |
| +--------+ +--------+ +--------+ |
+-------------------+-------------------------+
+-------------------+-------------------------+
Pred. filters: node 3 doesn't have enough resource
+-------------------+-------------------------+
+-------------------+-------------------------+
| +--------+ +--------+ |
| | node 1 | | node 2 | |
| +--------+ +--------+ |
+-------------------+-------------------------+
+-------------------+-------------------------+
Priority function: node 1: p=2
+-------------------+-------------------------+
select max{node priority} = node 2