[rrd-developers] DS idea

[Alex van den Bogaerdt]

----- Original Message ----- 
From: "Tobias Oetiker" <tobi at oetiker.ch>
To: "Alex van den Bogaerdt" <alex at vandenbogaerdt.nl>
Cc: <rrd-developers at lists.oetiker.ch>
Sent: Monday, October 11, 2010 8:05 AM
Subject: Re: [rrd-developers] DS idea


> Hi Alex,
>
> Today Alex van den Bogaerdt wrote:
> [...]
>
>> That is because in that example, I want MAX, not LAST.
>
> for MAX and MIN it would work I agree ...


The OP:
"However, part of the collected samples are maximum wait times of queueing 
systems. These numbers are not guesswork but calculated exactly while 
servicing. I am very much interested in seeing the maxima of these maximum 
wait times later when I query a MAX-RRA. Currently, RRD interpolates to the 
grid first and than computes the maximum."

So MAX is what is needed.

And why do you only agree for MIN and MAX, thus implicitly not for LAST ?

In case you worry about further consolidation: don't. I think there will 
always be that one corner case where someone wants the last of the input, 
and then use max for further consolidation. Or vice versa. Or similar. 
Sometimes rrdtool is just not the right tool for a job.

Creating new DSTs is not the way to go imho. Especially not if the tool can 
do what is asked from it.