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20030430: whistler's clock is off

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  • Subject: 20030430: whistler's clock is off
  • Date: Wed, 30 Apr 2003 14:47:29 -0600
>From: Unidata User Support <address@hidden>
>Organization: Unidata Program Center/UCAR
>Keywords: LDM-6 IDD rtstats ntpdate

Hi Bryan,

In looking through the LDM-6 real time statistics, I notice that whistler's
clock is off:

http://www.unidata.ucar.edu/staff/chiz/rtstats/siteindex.shtml?whistler.creighton.edu

In particular, check out the 'latency' link for the IDS|DDPLUS feed.
You can see that the clock on whistler is continuously drifting, and
without the drift, your ingest latencies would probably be close to zero.

Could you setup 'root's cron on whistler to set the clock?

Here is an example of how to run ntpdate out of root's cron:

0 * * * * /usr/sbin/ntpdate timeserver > /dev/null

You would replace 'timeserver' with the fully qualified hostname for
the time server you would access to set your clock.  Lists of Stratum
1 and 2 time servers can be found, respectively in:

Stratum 1::

http://www.eecis.udel.edu/~mills/ntp/clock1a.html

Stratum 2::

http://www.eecis.udel.edu/~mills/ntp/clock2a.html

I have been advising folks to look through these web pages and identify
a public Stratum 2 server that is "close" to them.  Using the time
service from these folks typically requires that you send them an
email that you are doing so.

Thanks in advance.

Tom Yoksas

>From address@hidden Wed Apr 30 20:25:22 2003

Evening Tom,

Thanks for the heads up.  Normally, I run ntpd as we have a local NTP 
server on campus, but since building our new Dell server, I forgot to 
enable that at startup.  So, your stats showed the results of that.  It 
is now fixed, and I will check it over the next few days and make sure 
things are working correctly.  Thanks again!

Bryan