I'll be upgrading our Powerdns install on Wednesday. Because our system
is redundant and I'll only upgrade one node at a time, I don't expect
any service interruption. As always, though, unexpected mishaps may
cause brief service interruptions. Most likely these interruptions
would be confined to new VM creation, but in the worst case there might
be short periods of total DNS failure.
I plan to start the work at around 17:00 UTC (that's 09:00 in San
Francisco) and the total upgrade will take an hour or two.