[bind10-dev] numeric/integer size on CC channel

[Francis Dupont]

> I have not been part of the full discussion, but statistical data should roll
>  over, as counters keep incrementing.
> 
> In order to detect from the collector side, it is important to have an indica
> tor from 'when' the server was started, so that it can be compared against th
> e previous value.
> 
> In BIND9 there is the 'boot-time' element in the XML which I use extensively 
> to determine wether it's safe to subtract the value from the previous sample,
>  and if the value is less than the previous but has the same boot-time, it me
> ans that the counter rolled over.
> 
> This is why I believe it's important to define 64bit counters, and use a simu
> lated 64bit using a two pair 32-bit in 32-bit architectures.. BIND9 covers th
> is pretty well, perhaps we should re-use some of that?

=> I join Francisco and I add that on a multi-threaded system the big
counters must be protected against simultaneous increment.

Regards

Francis Dupont <fdupont at isc.org>

PS: even a 64 bit counter can wrap so the real question is whether
it can wrap more than once between two collections.