Smokeping rrdtool fetch

Question

How to fetch data from smokeping rrd file and make output with txt file when host go down or up in perl or php?

I send 10 ICMP packets every 60sec.
I want to fetch data from rrd and parse it to have such output:

17 Jun 2015 12:03:00 - host is down
17 Jun 2015 12:05:00 - host is up

E.g. host down when no data received or packet loss > 50%

I've already tried:

rrdtool fetch /var/lib/smokeping/Host/Swadzim.rrd AVERAGE
 1434546000: -nan 0.0000000000e+00 1.1677527778e-02 9.5520694444e-03 1.0010958333e-02 1.0222916667e-02 1.0669152778e-02 1.1147625000e-02 1.1677527778e-02 1.2782055556e-02 1.3641402778e-02 1.5893805556e-02 2.0290416667e-02 1434546720: -nan 0.0000000000e+00 1.0685083333e-02 9.2544444444e-03 9.5931388889e-03 9.9897500000e-03 1.0258138889e-02 1.0441527778e-02 1.0685083333e-02 1.1117277778e-02 1.1553638889e-02 1.2946375000e-02 1.4254041667e-02

Answer 1

I think you've a mistaken impression of what rrdtool does. It's a very nice tool for collecting time series data, collating it and archiving it. But inevitably - when you do archive the data, you lose resolution because you're aggregating your results.

Now, what smokeping does is - ping a server, keeps track of latency and packet loss.

That's all to the good, but if you want to monitor and alarm based on this - what you really need is to do the ping test yourself, rather than reading out of archive logs. At best - you'll be getting out of date information.

You can probably extract the data you need from the rrd. I can't do this for you, because I don't have enough information. What you need to do is:

• Figure out which of the data sources (DS) in your RRD you're interested in.
• Figure out which of the Round-Robin-Archives (RRAs) you want to look at.
• Retrieve the recent data for that sample.
• Alert based on it.

rrdtool fetch which you refer to - is a step in the right direction. You'll probably need something like:

rrdtool fetch filename.rrd AVERAGE -s -5m 

But then - from the values you get - you'll need to figure out which ones are relevant. (You might want to look at the LAST consolidation function as well as that may be relevant).

rrdtool info filename.rrd

can help you figure this out - it will list the data sources you're logging (in order).

But really - it's just much easier to catch the results of the ping in the first place, rather than ping something, process the data, archive it, consolidate it, and extract a time averaged consolidated result from the archive.

Answer 2

Why not use the alerts built into smokeping? They are pretty flexible and can do what you need

https://oss.oetiker.ch/smokeping/doc/smokeping_config.en.html and search for * Alerts *

For example

*** Alerts ***
to = [email protected]
from = [email protected]

+bigloss
type = loss
# in percent
pattern = ==0%,==0%,==0%,==0%,>0%,>0%,>0%
edgetrigger = yes
comment = suddenly there is packet loss