[ntp:hackers] What to do when the offset is WAYTOOBIG

David L. Mills mills at udel.edu
Wed Apr 18 20:18:17 PDT 2007


I am watching five clocks. Three of the say 1200, two say 1300 and my 
clock says 1400. Since the majority of clocks I watch say 1200, I 
conclude the real time is 1220, but that is beyond my panic limit of one 
hour. Should I wait until things "get better"? I think not. I could make 
the panic limit over two hours and things would get better real quick. 
Or, I could use the -x option. so the first panic would be forgiven and 
my clock would read 1200. If after that a warp occurs over 1000 s 
relative to the majority clique, there may be a stuck bit in the 
hardware clock (that's happened) and I need to jump the train right away.


Brian Utterback wrote:

> But is this a valid characterization? And even if it is mostly true, 
> what harm is there in waiting to see if it gets better. I think Judah 
> has the right idea, namely if the going get tough, just sit down, shut
> up and pretend that you don't exist until things get better. That is,
> go ahead and yell, don't step the clock but don't serve time in case
> you might be off, but be willing to start up again if things get better
> later. This seems like the best of both worlds.
> David L. Mills wrote:
>> The philosophical basis of this design is very carefully considered 
>> in the book. However, the simple characterization of the panic 
>> threshold is that if exceeded, it will not get better no matter how 
>> long you wait.

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