[ntp:questions] ntp documentation
Dennis Hilberg, Jr.
timekeeper at dennishilberg.com.invalid
Thu Jan 17 02:51:35 UTC 2008
Pat Farrell wrote:
> On Fri, 04 Jan 2008 22:19:04 +0000, Steve Kostecke wrote:
>> The NTP FAQ is available at http://www.ntp.org/ntpfaq/NTP-a-faq.htm
> Is there any documentation of the public graphs?
> For instance, my server is at
> I'm not sure what the 'offset' mean. Recently my graph shows lots of blue
> above the Y axis, I have no idea what that's telling me.
The pool score/offset graphs are explained at the bottom of your server's
score page where it says "What do the graphs mean?"
Quoted from the score page:
The Score graph
A couple of times an hour the pool system checks the time from your server
and compares it to the local time. Points are deducted if the server can't
be reached or if the time offset is more than 100ms (as measured relatively
crudely from the monitoring systems). More points are deducted the bigger
the offset is.
When the score goes down the background color in the top part of the chart
will reflect how severely the "outage" is. The color scale goes from blue
(very little) to yellow to orange to red (the server is several seconds off
or unreachable). Because of how the graph is averaged out, you can't always
infer what happened from the color. It's only meant as a tool to visualize
trends. For more exact details of what the monitoring system found you can
click on the CSV link.
The Offset graph
The monitoring system works roughly like an SNTP (RFC 2030) client, so it is
more susceptible by random network latencies between the server and the
monitoring system than a regular ntpd client would be. In other words: Don't
be alarmed by the occasional large offset and please don't use the offset as
an absolute performance metric.
Dennis Hilberg, Jr. \ timekeeper(at)dennishilberg(dot)com
NTP Server Information: \ http://saturn.dennishilberg.com/ntp.php
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