Raw ICMP Latency Results and Issues with Max/Min/Avg Latency

Help
1

Hi Everyone,

Is there a way to pull the raw ICMP Latency results form the performance data rather than using the summarised Max/Min/Avg results?

I notice on various occasions that even with 0 loss I have Avg Latency results Less than the Min which cant be right.

Thanks
P

2

Raw values are in the database in the device_perf table.

3

Hi,

The device_perf table only has columns min, max and avg.

My reading of the documentation and charts, is these are not the raw results, they are summarised results. Is that correct?

Regards
Peter

4

It is the summary of the 3 (by default) that are sent together every poll. There are entries for every poll, so , no it is not aggregated over time, only within each distinct attempt.

If you want “raw” results set ping attempts to 1 (this is a dumb idea).

5

Thanks Murrant,

Yes its a summary not aggregation.

I would had thought you could easily get the raw data. The big reason i am asking for the raw data is I can see in quite a number of polls where Avg is less than Min which is wrong and the analysis I am doing requires a high degree of accuracy.

Would setting Ping Attempts = 2 achieve the same result?

Thanks
Peter

6

If you have avg,min,max at all it is an aggregate/summary. But it is only for that one poll.

So, here is how it works:
Poll #1:
fping -c 3 pings 3 times then returns:
xmt/rcv/%loss = 3/3/0%, min/avg/max = 0.020/0.023/0.027
Librenms records that data
Poll #2:
fping -c 3 pings 3 times then returns:
xmt/rcv/%loss = 3/3/0%, min/avg/max = 0.020/0.024/0.030
Librenms records that data

So, as you can see, it is only the data from fping for each poll being recorded. LibreNMS does no calculation on the data. Simply stores it.

7

Thanks,

I do understand what you are saying how Libre is recording the results, but the issue I have is I am getting some weird results like:

Loss = 0% and Min/Avg/Max = 640/166/6703

Another result is Min/Avg/Max = 1465/655/7862 and there are many others like this.

This makes no sense since Avg is less than the Min.

So you are saying the issue will be the fping -c 3 and Libre is just recording the result.

I do notice the issue is more prevalent when the Max result is close to the 8000ms limit.

8

That is odd. I suggest you run fping by hand and check the results.

There is a possibility there is an error in LibreNMS’ parsing the data from fping. Or perhaps fping itself has a bug.

Edit, I just found there is this lnms device:ping <hostname> Not sure how helpful that is.

9

Thanks for that.

10

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