Possible critics and answers:
- the PIM model is expensive, because it requires every node to have the capabilities necessary to execute the CP. Furthermore, at any given time, only one node is actually execute the CP. This leads to an high waste of resources. We can argue that nowadays the cost of the hardware is lower than the cost for developing a good coordination algorithm;
- if the CP migrates too often, then the migration overhead will become unacceptable. For this reason, we should migrate the CP only when and where it is really needed;
- the caching mechanism makes the CP move with the data, not to the data, so we should use the caching mechanism only when it is really needed.