[rrd-developers] How to create a new Data Type and Consolidation Function?

[Dan Cech]

On 4/12/2011 1:38 PM, Long V wrote:
> My function is keeping a SUM of the COUNTER difference. Let's illustrate with an
>
> example.
>
> time           ___1 ___2 ___3 ___4 ___5 ___6 ___7 ___8
> counter_value  _300 _450 _450 _900 1200 1800 2100 2550
> diff_sum_res_1 _300 _150 ___0 _450 _300 _600 _300 _450
> diff_sum_res_2    _450      _450      _900      _750
> diff_sum_res_4         _900                1650

Back up a second, for a regular COUNTER the rate is just the raw 
difference divided by the time delta, so you can construct your 
cumulative difference data from the AVERAGE easily with a CDEF.

Assuming a 60 second step:

time           ___0 ___1 ___2 ___3 ___4 ___5 ___6 ___7 ___8
counter_value  ___0 _300 _450 _450 _900 1200 1800 2100 2550
rate1               ___5 _2.5 ___0 _7.5 ___5 __10 ___5 _7.5
rate1 * 60          _300 _150 ___0 _450 _300 _600 _300 _450
rate2                  3.75      3.75     _7.5       6.25
rate2 * 120            _450      _450     _900       _750
rate3                       3.75                6.875
rate3 * 240                 _900                _1650

What am I missing here?

Dan