[rrd-users] More observations and questions on COUNTER

Simon Hobson linux at thehobsons.co.uk
Sat Oct 23 19:49:54 CEST 2010

Philip Peake wrote:

>>What value does your source have when it comes back online ?
>>I'd still suggest modifying your script(s) to log the update values
>>to a text file - it will help enormously if you can provide a set of
>>update statements that replicates the problem. Without that we are
>>guessing, and you've already "changed the story" as I was assuming
>>your were immediately storing real values after the reset (and
>>wondering why the zeros before the spike).
>No change -- someone didn't read the original post, which includes 
>an example of the type of data seen:
>>What I see if I look back over the data is a sequence looking like this
>>(simplified, with thee data sources):
>>T1    1000    1004    997
>>T2    1010    1020    1003
>>T3    NaN     Nan     NaN
>>T4    NaN     NaN     NaN
>>T5    0        0        0 
>>T6    0        0        0
>>T7    0        0        0
>>T8   4E6      4E6      4E6
>>T9    15      12       10

Yes I read the original post - but you didn't say that you put the 
zeros there -and I was wondering where on earth they came from.

>Just to be clear, they way it works is:
>* Read fails - substitute a 'U' for the data.
>* Mark data source as down.
>* Schedule re-connect to data source for five minutes in the future.
>In 30 second loop:
>* For each data source, read value. if a DS is marked down, substitute zero.
>So when a DS goes down, we will get a NaN, followed by a string of 
>zeros, until the DS comes back online.
>At that point, the value actually read will be sent to the DB.
>Here is the actual DB content:

I don't want to see what's in the database. Please provide a set of 
update values that reproduce the problem. If we don't know what went 
in, then we cannot even guess at whether what comes out is correct or 

Simon Hobson

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