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Unexpected times on "Connection Times" graph

list Jeremy Laidman
Tue, 25 Aug 2015 13:04:36 +1000
Message-Id: <user-0d0a4db255ef@xymon.invalid>

I've noticed the same thing on many of my servers.  Without really thinking
about it, I just assumed that the xymonnet TCP connection measurements were
taking into account (removing) network latency time, and only giving the
latency within the server being tested.  Thinking about it now, I'm not
sure how xymonnet would do this.

Yes, I believe xymonping uses ICMP.  You can run xymonping directly like:

sudo -u xymon /usr/lib/xymon/server/bin/xymonping 10.100.2.17

and see how it compares with the graph, or "ping" or "time telnet
10.100.2.17 22 </dev/null".

J


On 25 August 2015 at 08:02, Shawn Heisey <user-5d0d01dba542@xymon.invalid> wrote:
Here is a "connection times" graph from Xymon:

https://www.dropbox.com/s/voyqnzfnsqaact9/xymonresponsegraph.png?dl=0

This shows "conn" times in the 40 millisecond rang, and "ssh" times in
the 200 microsecond range.

What is the source of the "conn" graph?  I would have guessed ICMP, but
it doesn't make any sense for a ping to take longer than an ssh
connection, especially not that much longer.  This is what I get if I
ping that machine from the xymon server ... it doesn't take anywhere
even CLOSE to 40 milliseconds:

[root at mcp xymon]# ping palazzo
PING palazzo.REDACTED.com (10.100.2.17) 56(84) bytes of data.
64 bytes from palazzo.REDACTED.com (10.100.2.17): icmp_seq=1 ttl=62
time=0.572 ms
64 bytes from palazzo.REDACTED.com (10.100.2.17): icmp_seq=2 ttl=62
time=0.582 ms
64 bytes from palazzo.REDACTED.com (10.100.2.17): icmp_seq=3 ttl=62
time=0.573 ms
64 bytes from palazzo.REDACTED.com (10.100.2.17): icmp_seq=4 ttl=62
time=0.611 ms
64 bytes from palazzo.REDACTED.com (10.100.2.17): icmp_seq=5 ttl=62
time=0.890 ms
^C
--- palazzo.REDACTED.com ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4003ms
rtt min/avg/max/mdev = 0.572/0.645/0.890/0.126 ms

Can anyone shed light on this?  My server config includes the following
line:

FPING="xymonping"

My xymon server is version 4.3.14.

Thanks,
Shawn