[rrd-users] More observations and questions on COUNTER

Sat Oct 23 18:00:01 CEST 2010

On 10/23/2010 8:42 AM, Simon Hobson wrote:
> Philip Peake wrote:
>> Simon, the script forces log data on 30 second boundaries, I use
>> calculated times, not "now".
>> This includes the NaN value when a data source disappears, and for the
>> zero values entered into it every 30 seconds until the source comes back
>> online.
> OK, that rules out a conflict between updates and reset. The bit 
> about zeros while the data source is away is new - you didn't mention 
> that.
>
>> I have dumped the DB values, and see exactly what I expect
> With all due respect - yu apparently aren't seeing what you expect, 
> hence the query !
>
>>  - increasing
>> values, a NaN (well, I actually got two Nans), then a string of zeros
>> followed by a HUGE number (rrd thinks a counter rollover occurred, but
>> only when it sees a non-zero data value ????)  followed by data source
>> readings.
> 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

There seem to be a sequence of zeros there ... no?

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:

1287767520: 3.5333333333e+01 2.7066666667e+01 3.0866666667e+01
3.3033333333e+01 2.4733333333e+01 5.9566666667e+01 3.7766666667e+01
2.3133333333e+01 2.6200000000e+01

1287767550: 3.8900000000e+01 2.5533333333e+01 3.2033333333e+01
3.4133333333e+01 2.6033333333e+01 6.3866666667e+01 4.8066666667e+01
2.5500000000e+01 2.9066666667e+01

1287767580: 3.6966666667e+01 2.7166666667e+01 3.3033333333e+01
2.8300000000e+01 2.4066666667e+01 6.2033333333e+01 3.4833333333e+01
2.1233333333e+01 2.7266666667e+01

1287767610: 3.6400000000e+01 2.4433333333e+01 3.0633333333e+01
2.7466666667e+01 2.1700000000e+01 5.7400000000e+01 4.3600000000e+01
2.0633333333e+01 1.8933333333e+01

1287767640: 3.5200000000e+01 2.3066666667e+01 2.8200000000e+01
3.0700000000e+01 2.3466666667e+01 6.1633333333e+01 2.9266666667e+01
1.7700000000e+01 2.4466666667e+01

1287767670: 3.7433333333e+01 2.7733333333e+01 3.3000000000e+01
3.3866666667e+01 2.8500000000e+01 5.8666666667e+01 4.3700000000e+01
2.5766666667e+01 2.6633333333e+01

1287767700: 3.6366666667e+01 2.3633333333e+01 2.8300000000e+01
2.9833333333e+01 2.0933333333e+01 5.8000000000e+01 3.4400000000e+01
2.3666666667e+01 2.4000000000e+01

1287767730: 3.8833333333e+01 3.6900000000e+01 3.6800000000e+01
3.9566666667e+01 2.6866666667e+01 6.2800000000e+01 4.4000000000e+01
3.0700000000e+01 3.0400000000e+01

1287767760: 3.6366666667e+01 3.6533333333e+01 3.9066666667e+01
4.2300000000e+01 3.4100000000e+01 6.8600000000e+01 4.2866666667e+01
3.5633333333e+01 3.6166666667e+01

1287767790: 3.4700000000e+01 2.2100000000e+01 2.9333333333e+01
3.7933333333e+01 2.5633333333e+01 5.7800000000e+01 4.4100000000e+01
2.5700000000e+01 3.5333333333e+01

1287767820: 3.3866666667e+01 2.4200000000e+01 2.8833333333e+01
3.4766666667e+01 2.9233333333e+01 6.0933333333e+01 3.7066666667e+01
2.5700000000e+01 2.5700000000e+01

1287767850: nan nan nan nan nan nan nan nan nan

1287767880: nan nan nan nan nan nan nan nan nan

1287767910: 0.0000000000e+00 0.0000000000e+00 0.0000000000e+00
0.0000000000e+00 0.0000000000e+00 0.0000000000e+00 0.0000000000e+00
0.0000000000e+00 0.0000000000e+00

1287767940: 0.0000000000e+00 0.0000000000e+00 0.0000000000e+00
0.0000000000e+00 0.0000000000e+00 0.0000000000e+00 0.0000000000e+00
0.0000000000e+00 0.0000000000e+00

1287767970: 0.0000000000e+00 0.0000000000e+00 0.0000000000e+00
0.0000000000e+00 0.0000000000e+00 0.0000000000e+00 0.0000000000e+00
0.0000000000e+00 0.0000000000e+00

1287768000: 0.0000000000e+00 0.0000000000e+00 0.0000000000e+00
0.0000000000e+00 0.0000000000e+00 0.0000000000e+00 0.0000000000e+00
0.0000000000e+00 0.0000000000e+00

1287768030: 0.0000000000e+00 0.0000000000e+00 0.0000000000e+00
0.0000000000e+00 0.0000000000e+00 0.0000000000e+00 0.0000000000e+00
0.0000000000e+00 0.0000000000e+00

1287768060: 0.0000000000e+00 0.0000000000e+00 0.0000000000e+00
0.0000000000e+00 0.0000000000e+00 0.0000000000e+00 0.0000000000e+00
0.0000000000e+00 0.0000000000e+00

1287768090: 0.0000000000e+00 0.0000000000e+00 0.0000000000e+00
0.0000000000e+00 0.0000000000e+00 0.0000000000e+00 0.0000000000e+00
0.0000000000e+00 0.0000000000e+00

....

1287768450: 0.0000000000e+00 0.0000000000e+00 0.0000000000e+00
0.0000000000e+00 0.0000000000e+00 0.0000000000e+00 0.0000000000e+00
0.0000000000e+00 0.0000000000e+00

1287768480: 0.0000000000e+00 0.0000000000e+00 0.0000000000e+00
0.0000000000e+00 0.0000000000e+00 0.0000000000e+00 0.0000000000e+00
0.0000000000e+00 0.0000000000e+00

1287768510: 0.0000000000e+00 0.0000000000e+00 0.0000000000e+00
0.0000000000e+00 0.0000000000e+00 0.0000000000e+00 0.0000000000e+00
0.0000000000e+00 0.0000000000e+00

1287768540: 2.5901286667e+06 6.3913936667e+05 2.8650751333e+06
3.9261653333e+06 6.5304750000e+05 1.9967121000e+06 6.6341213333e+05
3.0846810333e+06 3.4084224000e+06

1287768570: 2.9600000000e+01 1.8233333333e+01 2.6966666667e+01
3.6666666667e+01 2.3133333333e+01 6.3000000000e+01 4.1733333333e+01
1.8100000000e+01 2.5700000000e+01

1287768600: 3.3533333333e+01 2.1366666667e+01 2.5100000000e+01
2.9033333333e+01 2.1466666667e+01 6.2166666667e+01 3.3200000000e+01
2.2133333333e+01 2.3433333333e+01

1287768630: 5.8900000000e+01 4.5400000000e+01 4.8666666667e+01
4.0333333333e+01 2.8966666667e+01 6.8666666667e+01 4.6433333333e+01
4.3733333333e+01 3.6300000000e+01

1287768660: 3.7066666667e+01 2.8200000000e+01 3.5933333333e+01
3.5733333333e+01 2.9700000000e+01 6.8666666667e+01 4.3466666667e+01
3.6233333333e+01 3.5466666667e+01

1287768690: 3.5100000000e+01 2.9733333333e+01 4.3900000000e+01
2.8033333333e+01 2.2300000000e+01 6.1433333333e+01 4.6766666667e+01
2.4966666667e+01 6.2766666667e+01

1287768720: 4.1300000000e+01 2.8600000000e+01 3.5550000000e+01
3.4733333333e+01 2.4100000000e+01 6.4016666667e+01 4.0183333333e+01
1.8750000000e+01 1.7033333333e+01

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.oetiker.ch/pipermail/rrd-users/attachments/20101023/b63a57ac/attachment.htm 