targeting a specific instance in a cluster

We have a few static objects that cache data from a database. We also have the requirement to be able to refresh the data within these objects without restarting the entire cluster or individual instances. I have written "reset" methods for these objects which re-reads it's associated data from the database. From my understanding of WL, calling the "reset" method will only reset the data in the object of the instance that handled the request. Anyody know how I can specifically target each instance, or somehow tell it to affect the entire cluster?
Thanks!