NTP Statistics

NTP Statistics

Post by Steve Pear » Wed, 30 Jan 2008 05:58:35


Hi,
I am using ntpv4.2.0 and have a question about the system statistics
interpretation on my NTP server.

The ntp page on monitoring options lists 11 'system stat' fields as
follows.
http://www.yqcomputer.com/ ~mills/ntp/html/monopt.html

MJD date
time past midnight
time since restart
packets received last hour
server packets received last hour
current version packets last hour
previous version packets last hour
access denied packets last hour
bad length or format packets last hour
bad authentication packets last hour
rate exceeded packets last hour

A sample of my daily filegen output is as follows (12 fields):
54493 514.622 117 12 3 12 0 0 0 0 0 0
54493 4118.319 118 14 2 14 0 0 0 0 0 0
54493 7722.012 119 13 3 13 0 0 0 0 0 0

It is critical for me to understand the meaning of each of the stats
to properly monitor my NTP deployment. Can someone please point me to
more detailed descriptions or maybe just confirm and comment on my
guesses below.

My interpretation of the stats meaning (for my 1st line output listed
above) is as below:

54493 - MJD date
514.622 - UTC time past midnight in seconds
117 - time since restart (in hours? or is this just a record count?)
12 - packets received last hour (NTP req packets from clients last
hour)
3 - Server Packets received last hour (packets from other servers??)
12 - current version packets last hour (NTP req packets from clients
using same version of NTP)
0 - previous version packets last hour
0 - access denied packets last hour (not allowed to synchronize with
me???)
0 - bad length or format packets last hour
0 - bad authentication packets last hour (bad MD5 check??)
0 - rate exceeded packets last hour (exceeded the min poll rate or
some such?)
0 - extra field not described on web????

Most critical for me is that I understand that "packets received last
hour" is really a count of NTP requests from clients. I want to use
this to get a rough idea of the load on my server to use for scaling
and monitoring.

thanks,
Steve
 
 
 

NTP Statistics

Post by Harlan Ste » Wed, 30 Jan 2008 07:53:27

>>> In article < XXXX@XXXXX.COM >, Steve Pearson < XXXX@XXXXX.COM > writes:

Steve> Hi, I am using ntpv4.2.0 and have a question about the system
Steve> statistics interpretation on my NTP server.

Steve> The ntp page on monitoring options lists 11 'system stat' fields as
Steve> follows. http://www.yqcomputer.com/ ~mills/ntp/html/monopt.html

Those are Dave's pages, and they reflect the latest -dev code.

For now, the best thing for you to do is get the source code for the version
you are running and look at the code.

The NTP Forum has projects listed to improve the documentation:

http://www.yqcomputer.com/
http://www.yqcomputer.com/

Another thing the NTP Forum will be helping support.ntp.org have
web-searchable documentation for different versions of NTP.

A significant purpose of the NTP Forum is to find the places where NTP is
giving you "headaches" and then making those headaches go away.

I'm eager to work with folks to get their companies signed up as
institutional members in the NTP Forum so we can get rid of the pain and
have significantly better lives where NTP is concerned.
--
Harlan Stenn < XXXX@XXXXX.COM >
http://www.yqcomputer.com/ - be a member!

 
 
 

NTP Statistics

Post by David L. M » Wed, 30 Jan 2008 09:21:25

Steve,

The best place to check the data is in the ntp_util.c file,
record_sys_stats() routine. I recently added another stat, but you might
not be using the most recent version.

The time since startup is in hours. The packets received are the total
number of packets received. The server packets received are in response
to packets sent from an association on your machine.

There are so many little trails in and out of the machine, like
control/monitor packets, etc., and so many little ways a packet can be
dropped, that the counters might not catch each and every wee thing.

Dave