[ntp:questions] Number of Stratum 1 & Stratum 2 Peers

William Unruh unruh at invalid.ca
Sat Dec 6 04:33:14 UTC 2014


On 2014-12-05, Rob <nomail at example.com> wrote:
> William Unruh <unruh at invalid.ca> wrote:
>>>> For internal systems I would want four servers minimum, two on-site, and 
>>>> two on the company WAN,
>>>
>>> I think that is ridiculous.  Introducing too many safeguards often
>>> results in more failures due to extra complexity in the system.
>>
>> The problem with two is that if oneof the servers goes nuts-- for some
>> reason starts to give out the wrong time (ie, its time is not UTC time)
>
> a. that will almost never happen
> b. that will be caught by the monitoring (e.g. nagios) and an alert will
>    be sent and/or the system will be shut down automatically.

Would it not be nicer is the alert is sent, but the system still keeps
going and not shutting down? Shutting down a system seems like a pretty
heavy price to pay for not having three instead of 2 sources.

>
>> Of course your monitoring might catch this, or it might not, depending
>> on whether you had thought of this failure mode when you set it up. So
>> the clients could do this for days or weeks. Now if you do not care if
>> the time jumps around by a second, then this is fine. Some places
>> however need better time control than that.
>
> The monitoring for ntpd servers shipped by default with nagios has no
> problem detecting this.

And when it does, what happens-- the company goes out of business? Noone
cares? It also sends out for coffee and doughnuts for the IT team?



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