Inspired by ITS#7616 and looking at our monitoring:
If I bring up a syncrepl consumer with empty DB it seems contextCSN attribute
is missing in DB base entry during refresh phase.
This is nice because we could use that in the load-balancer health check to
prevent clients to connect to this replica until all data is loaded into the
consumer and contextCSN is present.
So is it guaranteed that contextCSN is missing during lengthy refresh phase?