[VoiceOps] DST handling
David Hiers
hiersd at gmail.com
Fri Nov 6 12:03:34 EST 2009
I may not have been clear before, but that's pretty much what we do.
David
On Fri, Nov 6, 2009 at 8:12 AM, Colin <zavoid at gmail.com> wrote:
> Why aren'y you recording all cdr's in GMT and adjusting call log displays as
> needed based on where the customer wants to see the call log in?
>
>
> Colin
>
> On Nov 6, 2009, at 11:06 AM, David Hiers wrote:
>
>> My system clocks are all within 1 second of time.gov just days after
>> the DST change. We made the jump all at once, got double the number
>> of hourly CDR files for an hour, and will get no CDR files for an hour
>> in the spring. Don't think that we did anything special...
>>
>> What do your clocks look like today?
>>
>> We show start time and duration for customer-facing reports.
>>
>> David
>>
>>
>> On Thu, Nov 5, 2009 at 9:28 PM, James Hess <mysidia at gmail.com> wrote:
>>>
>>> The NTP protocol uses UTC as reference time; UTC is a time zone that
>>> has no DST changes. If the real-time clock on a device is kept in
>>> a local time, the NTP implementation on the device has to translate
>>> to UTC and back.
>>> There should be no difference in the calculated UTC time before, or
>>> after time change caused by DST.
>>>
>>>
>>> On Thu, Nov 5, 2009 at 4:34 PM, Jonathan Thurman
>>> <jonathan at thurmantech.com> wrote:
>>>>
>>>> On Thu, Nov 5, 2009 at 3:16 PM, David Hiers <hiersd at gmail.com> wrote:
>>>> [...] It is the responsibility of the operator to get the clock in
>>>> sync to start with, then NTP will adjust for the natural drift.
>>>
>>> Adjusting clocks by large amounts by default can be dangerous.. there
>>> might be an accident on another NTP server. An evil hacker who can
>>> forge NTP packets may have cracked an expired Kerberos TGT, or may
>>> desire that a server execute a certain cron job over and over
>>> again....
>>>
>>> If the time is off by less than 128ms, NTP will slew. If it's off by
>>> more than that NTP will often step (make a large error correction)
>>> instead.
>>> But there is a "panic" limit to the error corrections. If the clock
>>> is too far off, NTP will simply exit. You can change the number of
>>> seconds, or set it to be unlimited [at own risk]:
>>>
>>> tinker panic 0
>>> ...
>>>
>>> In certain *ix distros, you also get stepping at NTP startup according to
>>> entries made in an /etc/ntp/step-tickers
>>>
>>>
>>> --
>>> -J
>>>
>> _______________________________________________
>> VoiceOps mailing list
>> VoiceOps at voiceops.org
>> https://puck.nether.net/mailman/listinfo/voiceops
>
>
More information about the VoiceOps
mailing list