Re: Are all_max_peak percentile calculations wrong?

It would be a good move to open a bug report to help tracking this issue
(http://bugs.cacti.net).
In case you have an example (e.g. set of rrd files and a graph or the like) this
would help reproducing this issue and verifying the fix.

Reinhard

On 25.10.2012 16:30, Florian Roscher wrote:
> Hello,
> 
> as far as I checked and understood the source code the
> calculations for 'all_max_peak' are wrong currently.
> 
> For type 'max' as well as 'all_max_peak' function 
> nth_percentile() is called with one $local_data_id,
> returning a nth_percentile for the given datasource as
> well as a calculated field 'nth_percentile_maximum'.
> 
> When using 'max', this field 'nth_percentile_maximum' is
> used and this looks right for me.
> 
> When using 'all_max_peak', the nth_cache is iterated, seeking
> for a maximum. But within each iteration the nth_percentile_maximum
> is used which should be the same for every local_data_id of that 
> RRD. I think the iteration should seek for the maximum of the
> n'th percentiles of the respective data sources.
> 
> 
> The following patch makes that happen:
> 
> root@cacti:/var/www/cacti_test# diff -u lib/graph_variables.php.20121008-dist  lib/graph_variables.php
> --- lib/graph_variables.php.20121008-dist	2012-10-25 15:18:56.000000000 +0200
> +++ lib/graph_variables.php	2012-10-25 15:58:42.000000000 +0200
> @@ -366,8 +366,8 @@
>  	}elseif ($regexp_match_array[4] == "all_max_peak") {
>  		for ($t=0;($t<count($graph_items));$t++) {
>  			if ((preg_match("/(AREA|STACK|LINE[123])/", $graph_item_types{$graph_items[$t]["graph_type_id"]})) && (!empty($graph_items[$t]["data_template_rrd_id"]))) {
> -				if (! empty($nth_cache{$graph_items[$t]["local_data_id"]}["nth_percentile_maximum"])) {
> -					$local_nth = $nth_cache{$graph_items[$t]["local_data_id"]}["nth_percentile_maximum"];
> +				if (! empty($nth_cache{$graph_items[$t]["local_data_id"]}{$graph_items[$t]["data_source_name"]})) {
> +					$local_nth = $nth_cache{$graph_items[$t]["local_data_id"]}{$graph_items[$t]["data_source_name"]};
>  					$local_nth = ($regexp_match_array[2] == "bits") ? $local_nth * 8 : $local_nth;
>  					$local_nth /= pow(10,intval($regexp_match_array[3]));
> 
> 
> Is anyone able and willing to comment on this, check 
> my investigations or correct me?
> 
> 
> Regards
> Florian
> 
> 
> 

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