[Xymon] Bug in xymonping reporting wrong data when pinging multiple hosts

[Jeremy Laidman]

Of course the solution is to use fping.  Henrik has previously stated that
fping is preferred over xymonping <
http://lists.xymon.com/archive/2012-January/033738.html>, and the fping.sh
script used when building will warn that "it is not yet fully stable".

I've just now installed fping (and configured Xymon to use it) and my
graphs are now showing much more reasonable values than before.

Nevertheless, it's not obvious in any documentation that xymonping will
give bad data.  The caveats on its use suggest (to me) that it can miss
some replies when large numbers of hosts are probed, but in practice it
gives bad data even when the number of hosts is two.

J



On 9 January 2013 10:39, Jeremy Laidman <jlaidman at rebel-it.com.au> wrote:

> Yup, I get this too, tested with v4.3.10 and v4.3.4.  It also shows up
> when I ping the localhost address repeatedly:
>
> sudo ./xymon-4.3.4/xymonnet/xymonping 127.0.0.1 127.0.0.1 127.0.0.1
> 127.0.0.1 127.0.0.1
> 127.0.0.1 is alive (20 ms)
> 127.0.0.1 is alive (0.02 ms)
> 127.0.0.1 is alive (24 ms)
> 127.0.0.1 is alive (0.02 ms)
> 127.0.0.1 is alive (0.02 ms)
>
> The 20ms and 24ms entries are wrong, and they change as I adjust the
> max-pps values, by a factor of 5.
>
> None of my conn graphs seems to be completely flatlined, but I have
> noticed that DNS test times are usually less than conn test times, which is
> a bit odd, but might be unrelated.  Hmm, now that I look at them, it seems
> all of my graphs but one are hovering close to either 24ms or 48ms.  The
> host that is the exception, with a conn graph that looks correct, happens
> to be the last entry if I sort all host IP addresses.
>
> J
>
>
>
> On 9 January 2013 05:49, Michael Beatty <Michael.Beatty at sherwin.com>wrote:
>
>>  Using Xymon 4.3.7
>> OS Linux SuSE
>>
>> I've been struggling to understand why certain hosts are almost always
>> reporting the exact same ping response time.  I've determined, that
>> xymonping isn't working, it is reporting incorrect data for half of the
>> hosts tested.
>>
>> I start by pinging 6 hosts, one at a time, everything is correct
>> *[xymon at mxbscs tmp]$ /home/xymon/server/bin/xymonping X.X.X.22
>> X.X.X.22 is alive (0.06 ms)
>> [xymon at mxbscs tmp]$ /home/xymon/server/bin/xymonping X.X.X.70
>> X.X.X.70 is alive (0.56 ms)
>> [xymon at mxbscs tmp]$ /home/xymon/server/bin/xymonping X.X.X.138
>> X.X.X.138 is alive (826 ms)
>> [xymon at mxbscs tmp]$ /home/xymon/server/bin/xymonping X.X.X.137
>> X.X.X.137 is alive (980 ms)
>> [xymon at mxbscs tmp]$ /home/xymon/server/bin/xymonping X.X.X.201
>> X.X.X.201 is alive (0.75 ms)
>> [xymon at mxbscs tmp]$ /home/xymon/server/bin/xymonping X.X.X.202
>> X.X.X.202 is alive (0.66 ms)
>> *
>>
>> Then, put them in the same command, the first, second, and fifth values
>> are wrong
>> *[xymon at mxbscs tmp]$ /home/xymon/server/bin/xymonping X.X.X.70 X.X.X.22
>> X.X.X.138 X.X.X.137 X.X.X.201 X.X.X.202
>> X.X.X.70 is alive (40 ms)
>> X.X.X.22 is alive (20 ms)
>> X.X.X.138 is alive (1307 ms)
>> X.X.X.137 is alive (1738 ms)
>> X.X.X.201 is alive (20 ms)
>> X.X.X.202 is alive (0.64 ms)*
>>
>>
>> Switch the order of the pings, the first, second, and fifth value are
>> exactly the same as the first time, and still wrong
>> [xymon at mxbscs tmp]$ /home/xymon/server/bin/xymonping X.X.X.201 X.X.X.202
>> X.X.X.137 X.X.X.138 X.X.X.70 X.X.X.22
>> X.X.X.201 is alive (40 ms)
>> X.X.X.202 is alive (20 ms)
>> X.X.X.137 is alive (1598 ms)
>> X.X.X.138 is alive (2069 ms)
>> X.X.X.70 is alive (20 ms)
>> X.X.X.22 is alive (0.04 ms)
>> [xymon at mxbscs tmp]$
>>
>> Switch the order again, now the third, fourth, and fifth values are wrong.
>> *[xymon at mxbscs tmp]$ /home/xymon/server/bin/xymonping X.X.X.137
>> X.X.X.138 X.X.X.201 X.X.X.202 X.X.X.70 X.X.X.22
>> X.X.X.137 is alive (1537 ms)
>> X.X.X.138 is alive (2016 ms)
>> X.X.X.201 is alive (40 ms)
>> X.X.X.202 is alive (20 ms)
>> X.X.X.70 is alive (20 ms)
>> X.X.X.22 is alive (0.06 ms)*
>>
>>
>> Another thing I have noticed is that by altering the max-pps value, you
>> get completely different results.
>> [xymon at mxbscs tmp]$ /home/xymon/server/bin/xymonping X.X.X.137 X.X.X.138
>> X.X.X.201 X.X.X.202 X.X.X.70 X.X.X.22 --max-pps=1
>> X.X.X.137 is alive (2000 ms)
>> X.X.X.138 is alive (1000 ms)
>> X.X.X.201 is alive (2000 ms)
>> X.X.X.202 is alive (1000 ms)
>> X.X.X.70 is alive (1000 ms)
>> X.X.X.22 is alive (0.06 ms)
>>
>> [xymon at mxbscs tmp]$ /home/xymon/server/bin/xymonping X.X.X.137 X.X.X.138
>> X.X.X.201 X.X.X.202 X.X.X.70 X.X.X.22 --max-pps=5
>> X.X.X.137 is alive (1500 ms)
>> X.X.X.138 is alive (1479 ms)
>> X.X.X.201 is alive (400 ms)
>> X.X.X.202 is alive (200 ms)
>> X.X.X.70 is alive (200 ms)
>> X.X.X.22 is alive (0.06 ms)
>>
>> [xymon at mxbscs tmp]$ /home/xymon/server/bin/xymonping X.X.X.137 X.X.X.138
>> X.X.X.201 X.X.X.202 X.X.X.70 X.X.X.22 --max-pps=25
>> X.X.X.137 is alive (765 ms)
>> X.X.X.138 is alive (896 ms)
>> X.X.X.201 is alive (80 ms)
>> X.X.X.202 is alive (40 ms)
>> X.X.X.70 is alive (40 ms)
>> X.X.X.22 is alive (0.04 ms)
>>
>>
>> It doesn't appear to be a problem with my configuration.  I checked the
>> www.xymon.com demo site, and there seems to be the same issue there.  The
>> signature of the bad data is easy to see in the graphs as good data has and
>> diverse line, where as bad data is a generally flat line.
>> These hosts look good:
>>
>> http://www.xymon.com/xymon-cgi/svcstatus.sh?HOST=pto.linuxbog.dk&SERVICE=conn
>> http://www.xymon.com/xymon-cgi/svcstatus.sh?HOST=dali.hswn.dk&SERVICE=conn
>>
>> These hosts look bad:
>>
>> http://www.xymon.com/xymon-cgi/svcstatus.sh?HOST=blixen.hswn.dk&SERVICE=conn
>> http://www.xymon.com/xymon-cgi/svcstatus.sh?HOST=wifi.hswn.dk&SERVICE=conn
>>
>>
>>
>>  --
>> Michael Beatty
>>
>>
>>
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>> http://lists.xymon.com/mailman/listinfo/xymon
>>
>>
>
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