@nlnetlabs I would want some inter-service protocol to connect and configure multiple instances. One of the features would be which service(s) is / are primary (not DNS primary) and which are secondary. Based upon this one could configure the primary/ies to do the signing and all others to follow. Whatever is configured could be made persistent using files. I agree files on disk are a PITA to sync, but it doesn’t get any simpler and resistant than this from my OP perspective.