placement-strategy="default|utilization", the node that has the least number of allocated resources gets consumed first.
placement-strategy="balanced", the node that has more free capacity gets consumed first.
placement-strategy="minimal", the first eligible node listed in cib gets consumed first.
capacity. While if we define multiple types of capacity, for example:
nodeA has more free cpus, nodeB has more free memory, their free capacities are equal.
nodeA has more free cpus, while nodeB has more free memory and storage, nodeB has more free capacity.