Hello,

2016-04-27 21:03 GMT+08:00 Arnold Schekkerman <[email protected]>:
>
> Hello Alica,
>
> On 27-04-16 10:24, Alica wrote:
> > Recently I managed to add a Garmin 18x LVC GPS receiver to my pool server,
> > which (sometimes) can achieve microsecond level error.
>
> Cool :-)
>

Thank you.

> > Sample ntpq -p
> >      remote           refid      st t when poll reach   delay   offset
> > jitter
> > ==============================================================================
> > -SHM(0)          .GPS.            0 l   36   64  377    0.000  -505.65
> > 19.344
> > *SHM(1)          .PPS.            0 l   36   64  377    0.000    0.002
> > 0.010
> > -118-163-81-62.H 192.168.0.2      2 u   64   64  377    3.551    0.508
> > 1.242
>
> "Nearby" clients will definitely get the better time. The pool DNS servers 
> try to return "nearby" NTP
> servers to the clients.
>

Sure. Taiwanese pool users may have a <10ms latency to my server, but
I am not sure if the microsecond level accuracy is noticeable in this
scenario.

> So, clients of the pool SHOULD NEVER count on pool servers providing such 
> high accuracy! If they end
> up at your server, your high accuracy is just a bonus.
>

Okay. Looks like many (if not most) of the pool users in Taiwan are
coming from Android devices. (Windows users tend to stick with
time.windows.com instead.) Some of them even probe at my httpd,
resulting these logs:

220-137-42-115.dynamic.hinet.net - - [22/Apr/2016:04:43:05 +0800] "GET
/ HTTP/1.1" 303 358 "-" "Dalvik/1.6.0 (Linux; U; Android 4.4.4; H628
Build/KTU84P)"
180-177-115-87.dynamic.kbronet.com.tw - - [22/Apr/2016:05:15:58 +0800]
"GET / HTTP/1.1" 303 358 "-" "Dalvik/2.1.0 (Linux; U; Android 5.0.1;
H828 Build/LRX22C)"

I have redirected them to www.pool.ntp.org, but I am afraid that human
users may even not notice it. Seems like these requests are coming
from misconfigured devices. If anybody knows the device string H628
and H828 means? The Build/KTU84P and Build/LRX22C simply refers to
Android version (4.4.4 and 5.0.1 respectively) hence does not provide
specific vendor/model information. Or should I deliver some Linux iso
files to exhaust their memory and/or storage? *evilgrin*

> > Serving avearge 11.5M people (23M Taiwanese population with only 2 IPv4
> > pool servers online) is very challenging for my 15yr+ old (Celeron 1GHz
> > from 2000) pool server. The incoming requests have never lower than 3k
> > packets/sec, with peak over 7k packets/sec...
>
> Providing 'better' time may attract people to configure your server directly 
> with
> your IP instead of the pool. In the end, your better time may become the 
> reason you
> are forced to take your server offline...
>
> At the moment NTP pool clients in Taiwan will benefit the most from *more* 
> local
> NTP servers in the pool. Perhaps you know someone to translate the 
> www.pool.ntp.org
> pages to Taiwanese? This might help others in Taiwan to join the pool as well.
>

Surely I can help translating the pool website into traditional
Chinese, which is also used in Hong Kong and Macau besides Taiwan. In
fact I DID translated some of the pages.
https://github.com/alicaccs/ntppool/tree/master/docs/ntppool/zh-TW
But the work stalled after join.html was translated, since my
experience of running a server in Taiwan does not comply with the
description (most servers get about 5-15 NTP packets per second...) at
all. :)

> Kind regards,
>   Arnold
>
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