Eon Mode - what is the difference between a primary and a critical subcluster?

Deb_Chatigny

In Eon mode, what is the difference between a primary subcluster and a critical subcluster?
@dsprogis @ybei

Eon Mode: Past, Present, Future

ybei

They are different notions.
Primary subcluster and secondary subcluster are distinguished by whether the nodes in that subcluster persist catalog and count towards quorum or not.
Critical subcluster, is calculated by Vertica to tell user which subcluster can't be shutdown at the moment, otherwise the entire cluster will go down.
Of course, secondary subcluster can never be critical.