State of the blocker bug
hmurray at megapathdsl.net
Wed Aug 16 20:58:06 UTC 2017
This isn't related to the bug, but often adds a layer of confusion when
trying to understand what is going on with DNS. The old ntpq -p had a few
lines of code that skipped some entries. I forget the details. I think it
skipped slots that hadn't received any responses yet.
I may have removed that code. If not, we should remove it. At least for me,
it often sent me on a wild goose chase. If we don't remove it, we should at
least document why that code is a feature.
The new DNS has a lot of logging. (Maybe too much.) That should help when
debugging, at least if you remember to look at the log file.
ntpd tries to send only one request per second. In the simple non-DNS case,
this happens by stepping through the peer list and bailing after it finds a
ready slot and sends a packet. At startup, the peers display will show a
"when" column going up by one second per line. I'm not sure how DNS is/was
tangled up with this.
When it bumps the polling interval, it also randomizes the next-poll time. I
think it adds a randomized half-poll interval.
I'm not 100% confident I understand this area...
The old pool code didn't create a peer slot when it got an IP Address from
DNS. It sent a request, then setup the peer slot when the response returned.
Thus there was no place to remember the iburst flag. I think this was
tangled up with peer mode which we have depricated.
These are my opinions. I hate spam.
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