Is a Kubernetes service cluster specific or can a service span across clusters?

If I have 3 Kubernetes clusters all sharing the same master components, and say I have an application foo running on several replicated pods across all 3 clusters. Then say there is a service foo-service which abstracts this application. Now, will this service be able to point incoming request for application foo to any of the pods across all 3 clusters? Also if this request comes from an external (outside all clusters) source, then how does Kubernetes decide which cluster to check first for the requested service?

What do you mean by sharing master components? That is a phrase that doesn’t make much sense.

That said, sig-multi-cluster has been spending some time looking at ways to make services span clusters. Not ready yet, but starting in earnest.