If I add logbase and syncfilter, I see the behavior where any serverID
other 1 (on either system) results in the looping mentioned previously,
when one server is down. In that setup with both servers up, I still
see the null_callback issues.
At this point I'm pretty frayed. I don't see how copying something
directly out of the admin doc would fail unless I've tickled a new bug.
Perhaps someone could suggest a known good, working config for me to
try? I would prefer delta-syncrepl in a mirror, but I'd settle for just
syncrepl with a mirror at this point.