[drraw-users] question regarding perl based DS and addition

[Christophe Kalt]

On 2009-01-05, eliott wrote:
> I am trying to use the perl regex based DS to graph cpu rrds.
> The problem I am running into, is the forumula + or AVERAGE when only
> one cpu is present on a box. Some boxes have 4. Others have one. Some
> of the boxes with 4 cpus don't provide all the data for each of the
> points (lets say cpu-4 on a host is the only cpu with any 'nice' cpu
> data).
>
> I get the following on boxes with one cpu, or many cpus where only one
> of 4 cpus has a datapoint:
>  invalid rpn expression in: e0,UN,0,e0,IF,,+

I've been meaning to take a closer look but sounds like a bug.

> My hope was to have a single template that I could apply to boxes with
> 1 cpu, as well as boxes with 4 cpus. Addition in rpn of course
> requires two items on the stack.

Right, you should be able to.

> Has anyone found a way to work around this issue, without resorting to
> creating a separate template?

Fixing that particular bug shouldn't be very hard.