[tor-relays] [WARN] Your system clock just jumped 100 seconds forward; assuming established circuits no longer work.

[Zenaan Harkness]

On 2/21/14, grarpamp <grarpamp at gmail.com> wrote:
>> something I did to ntpd.conf (probably adding servers above the
>> default debian entries which are:
>> server 0.debian.pool.ntp.org iburst
>
> The order doesn't matter. Though if DNS is not up before
> ntpd on boot, specified poolnames won't resolve and I think it's still a
> oneshot so only servers listed by ip would be loaded. see ntpq -np
> while listing a bogus hostname, a poolname, and an ip.

Well I have a couple of IP listings now, and I haven't seen the
~2minute jump since adding them.

So things have definitely improved on that front.

I still see rather wild deltas (upwards of a second sometime), but at
least it doesn't get worse than that:
Feb 22 11:26:38 lt8 ntpdate[4832]: step time server 192.189.54.17
offset 0.762756 sec
Feb 22 11:31:48 lt8 ntpdate[4836]: adjust time server 203.59.7.248
offset -0.052660 sec
Feb 22 11:37:00 lt8 ntpdate[4839]: adjust time server 203.23.237.200
offset 0.283965 sec
Feb 22 11:42:11 lt8 ntpdate[4841]: adjust time server 203.23.237.200
offset 0.151871 sec
Feb 22 11:47:26 lt8 ntpdate[4843]: adjust time server 150.101.247.149
offset 0.470046 sec
Feb 22 11:52:35 lt8 ntpdate[4845]: adjust time server 27.106.200.45
offset 0.063318 sec
Feb 22 11:57:46 lt8 ntpdate[4847]: adjust time server 130.102.128.23
offset 0.090110 sec
Feb 22 12:03:00 lt8 ntpdate[4851]: step time server 192.189.54.17
offset 0.515640 sec
Feb 22 12:08:12 lt8 ntpdate[4853]: adjust time server 192.189.54.17
offset 0.308896 sec
Feb 22 12:13:20 lt8 ntpdate[4855]: adjust time server 118.88.20.194
offset -0.162371 sec
Feb 22 12:18:33 lt8 ntpdate[4860]: adjust time server 128.184.218.53
offset 0.302422 sec
Feb 22 12:23:44 lt8 ntpdate[4915]: adjust time server 203.161.12.165
offset 0.162629 sec
Feb 22 12:28:54 lt8 ntpdate[4922]: adjust time server 203.161.12.165
offset 0.035504 sec

Your comment above reminds me of something else I saw:
log.3.gz:Feb 19 09:55:50.000 [warn] eventdns: All nameservers have failed
log.3.gz:Feb 19 09:59:07.000 [warn] Your system clock just jumped 100
seconds forward;

This only happened once or twice back then.

What this leads me to is a couple of things - have a couple ntp
servers listed as ip address in case there is dns problems, but also I
think that one thing that may have affected me is I had essentially no
throttling/bandwidth shaping on the tor relay - and if the
uplink/upload gets satturated, this used to be a problem for
bittorrent (still is I think) and probably for tor relay too - if
certain outgoing packets don't make it out in a timely manner, then
problems happen.

So I have set my RelayBandwidthBurst to 90KB (KiB) (and non-burst to
80KB) - it's an ADSL2 connection pretty close to the exchange, so the
full 1MiB upload is generally possible, I think. I'll see how I
continue to go at 90KB.

Thanks all,
Zenaan