[rrd-users] RRDtool spread values by time on rrd, how to turn off this behavior?

[Daniel Hilst]

On 04/17/2012 10:15 PM, Tobias Oetiker wrote:
> Hi Daniel,
>
> Yesterday Daniel Hilst wrote:
>
>> On 04/16/2012 01:19 PM, Daniel Hilst wrote:
>>> When I do an update on some rrd file the rrdtool -- or something --
>>> spread my input value by time.
>>>
>>> Here is how I reproduce:
>>>
>>> 1) Create my rrd with this command
>>> rrdtool create --step 10 test.rrd DS:v:GAUGE:600:U:U RRA:AVERAGE:0.5:1:50
>>>
>>> 2) The feed it with:
>>> rrdtool update test.rrd 1334578211:10
>>> rrdtool update test.rrd 1334578221:0
>>>
>>>
>>> I get
>>> 1334578210 9.000000
>>> 1334578220 1.000000
>>>
>>>
>>> The RRDtool have spread my values, so 9 + 1 = 10, Its cool, but some
>>> times I want 10, then 0.. Is there a way to turn this feature off for
>>> specific rrd file?
>>>
>>> If update rrd on 10 multiples then it works as I expect, so If I did:
>>> rrdtool update test.rrd 1334578210:10
>>> rrdtool update test.rrd 1334578220:0
>>>
>>> I would get
>>> 1334578210 10.000000
>>> 1334578220 0.000000
>>>
>>> I'm using collectd so I cant round up epoch..
>>>
>>>
>>> Thanks in advance!
>>>
>>> Cheers!
>>>
>> My solution was create a patch to collectd to round up the epoch before
>> submit..
>>
>> []'s
>>
>> Here is if is of any interest :)
>
> question: why would you want to lie about the data you acquired?
>
> if you need higher precision, then you need to up your sampling
> rate ...
>
> cheers
> tobi
>
>>
>

Hey tobias, I'm using collectd tail plugin to monitor Oracle database 
logs, matching ORA- errors. When I got one error at 1334578215 for 
example, on graph I'll see 0.5 error at 1334578210 and 0.5 error at 
1334578220 -- Remember that collectd uses 10 as step, so while 
generating graph I just multiply the value collected by 10. -- 0.5 error 
is not something readable, so I round epoch on rrdtool plugin to get an 
integer number, avoiding the interpolation.

Cheers :)

-- 
Follow the white rabbit!