Xymon Mailing List Archive search

Strange rrd problem

8 messages in this thread

list Thomas Kaehn · Fri, 13 Jul 2007 09:01:10 +0200 ·
Hi,

I've set up a hobbit server to monitor a couple of systems.

However the network test graphs from exactly one system are looking
quite strange:

http://www.westend.com/pop3-1.png
http://www.westend.com/pop3-2.png		(zoomed in view)

According to this graph pop3 is answering always within zero seconds (I
can't imagine this). And the response time of pop3s is alternating in
such specific way that rrd draws triangles.

I've already deleted the rrd files, but the effect remains the same.

The system is running Debian 4.0 (librrd2 version 1.2.15-0.3). Has
anybody seen such strange effects before? All other systems and even
other services on the same system are looking reasonable.

Ciao,
Thomas
-- 
Thomas Kähn                   WESTEND GmbH  |  Internet-Business-Provider
Technik                       CISCO Systems Partner - Authorized Reseller
                              Im Süsterfeld 6          Tel 0241/701333-18
user-02a72cb3f725@xymon.invalid                D-52072 Aachen              Fax 0241/911879
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Die Gesellschaft ist eingetragen im Handelsregister Aachen unter HRB 7608
Geschäftsführer:           Thomas Neugebauer, Thomas Heller, Michael Kolb
list Henrik Størner · Fri, 13 Jul 2007 12:49:22 +0200 ·
One reason for the flat always-zero pop3 graph could be that it 
responds faster than Hobbit monitors. If the response time is
less than 10 ms, then Hobbit will report it as zero - look at
the pop3 status page and see the "Seconds: x.xx" which is the
data that Hobbit uses for the graph.

As for the diamond-shaped graph - yes, this is quite puzzling.
I've had a couple of other reports (see e.g. this thread:
http://www.hobbitmon.com/hobbiton/2005/10/msg00332.html).
We haven't been able to figure out why this happens, the data
that goes into the RRD file look sane.


Regards,
Henrik
quoted from Thomas Kaehn


On Fri, Jul 13, 2007 at 09:01:10AM +0200, Thomas Kaehn wrote:
Hi,

I've set up a hobbit server to monitor a couple of systems.

However the network test graphs from exactly one system are looking
quite strange:

http://www.westend.com/pop3-1.png
http://www.westend.com/pop3-2.png		(zoomed in view)

According to this graph pop3 is answering always within zero seconds (I
can't imagine this). And the response time of pop3s is alternating in
such specific way that rrd draws triangles.

I've already deleted the rrd files, but the effect remains the same.

The system is running Debian 4.0 (librrd2 version 1.2.15-0.3). Has
anybody seen such strange effects before? All other systems and even
other services on the same system are looking reasonable.

Ciao,
Thomas
-- 
Thomas Kähn                   WESTEND GmbH  |  Internet-Business-Provider
Technik                       CISCO Systems Partner - Authorized Reseller
                              Im Süsterfeld 6          Tel 0241/701333-18
user-02a72cb3f725@xymon.invalid                D-52072 Aachen              Fax 0241/911879
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Die Gesellschaft ist eingetragen im Handelsregister Aachen unter HRB 7608
Geschäftsführer:           Thomas Neugebauer, Thomas Heller, Michael Kolb

-- 

Henrik Storner
list Thomas Kaehn · Fri, 13 Jul 2007 13:35:21 +0200 ·
Hi Henrik,
quoted from Henrik Størner

On Fri, Jul 13, 2007 at 12:49:22PM +0200, Henrik Stoerner wrote:
One reason for the flat always-zero pop3 graph could be that it 
responds faster than Hobbit monitors. If the response time is
less than 10 ms, then Hobbit will report it as zero - look at
the pop3 status page and see the "Seconds: x.xx" which is the
data that Hobbit uses for the graph.
OK, this would explain why zero is reported.
quoted from Henrik Størner
As for the diamond-shaped graph - yes, this is quite puzzling.
I've had a couple of other reports (see e.g. this thread:
http://www.hobbitmon.com/hobbiton/2005/10/msg00332.html).
We haven't been able to figure out why this happens, the data
that goes into the RRD file look sane.
The data in the rrd file looks strange however when dumped using
rrdtool. So every other value is different.

Ciao,
Thomas


<!-- 2007-07-13 05:55:00 CEST / 1184298900 --> <row><v> 3.0100000000e+00 </v></row>
<!-- 2007-07-13 06:00:00 CEST / 1184299200 --> <row><v> 3.0100000000e+00 </v></row>
<!-- 2007-07-13 06:05:00 CEST / 1184299500 --> <row><v> 2.6000000000e+00 </v></row>
<!-- 2007-07-13 06:10:00 CEST / 1184299800 --> <row><v> 4.3000000000e-01 </v></row>
<!-- 2007-07-13 06:15:00 CEST / 1184300100 --> <row><v> 2.6300000000e+00 </v></row>
<!-- 2007-07-13 06:20:00 CEST / 1184300400 --> <row><v> 4.1000000000e-01 </v></row>
<!-- 2007-07-13 06:25:00 CEST / 1184300700 --> <row><v> 2.6500000000e+00 </v></row>
<!-- 2007-07-13 06:30:00 CEST / 1184301000 --> <row><v> 3.9000000000e-01 </v></row>
<!-- 2007-07-13 06:35:00 CEST / 1184301300 --> <row><v> 2.6700000000e+00 </v></row>
<!-- 2007-07-13 06:40:00 CEST / 1184301600 --> <row><v> 3.7000000000e-01 </v></row>
<!-- 2007-07-13 06:45:00 CEST / 1184301900 --> <row><v> 2.6900000000e+00 </v></row>
<!-- 2007-07-13 06:50:00 CEST / 1184302200 --> <row><v> 3.5000000000e-01 </v></row>
<!-- 2007-07-13 06:55:00 CEST / 1184302500 --> <row><v> 2.7100000000e+00 </v></row>
<!-- 2007-07-13 07:00:00 CEST / 1184302800 --> <row><v> 3.3000000000e-01 </v></row>
<!-- 2007-07-13 07:05:00 CEST / 1184303100 --> <row><v> 2.7300000000e+00 </v></row>
<!-- 2007-07-13 07:10:00 CEST / 1184303400 --> <row><v> 3.0900000000e-01 </v></row>
<!-- 2007-07-13 07:15:00 CEST / 1184303700 --> <row><v> 2.7408666667e+00 </v></row>
<!-- 2007-07-13 07:20:00 CEST / 1184304000 --> <row><v> 2.9000000000e-01 </v></row>
<!-- 2007-07-13 07:25:00 CEST / 1184304300 --> <row><v> 2.7700000000e+00 </v></row>
<!-- 2007-07-13 07:30:00 CEST / 1184304600 --> <row><v> 2.6000000000e-01 </v></row>
<!-- 2007-07-13 07:35:00 CEST / 1184304900 --> <row><v> 2.7900000000e+00 </v></row>
<!-- 2007-07-13 07:40:00 CEST / 1184305200 --> <row><v> 2.4000000000e-01 </v></row>
<!-- 2007-07-13 07:45:00 CEST / 1184305500 --> <row><v> 2.8200000000e+00 </v></row>
<!-- 2007-07-13 07:50:00 CEST / 1184305800 --> <row><v> 2.2000000000e-01 </v></row>
<!-- 2007-07-13 07:55:00 CEST / 1184306100 --> <row><v> 2.8400000000e+00 </v></row>
<!-- 2007-07-13 08:00:00 CEST / 1184306400 --> <row><v> 2.0000000000e-01 </v></row>
<!-- 2007-07-13 08:05:00 CEST / 1184306700 --> <row><v> 2.8600000000e+00 </v></row>
<!-- 2007-07-13 08:10:00 CEST / 1184307000 --> <row><v> 1.8000000000e-01 </v></row>
quoted from Henrik Størner


-- 
Thomas Kähn                   WESTEND GmbH  |  Internet-Business-Provider
Technik                       CISCO Systems Partner - Authorized Reseller
                              Im Süsterfeld 6          Tel 0241/701333-18
user-02a72cb3f725@xymon.invalid                D-52072 Aachen              Fax 0241/911879
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Die Gesellschaft ist eingetragen im Handelsregister Aachen unter HRB 7608
Geschäftsführer:           Thomas Neugebauer, Thomas Heller, Michael Kolb
list S Aiello · Fri, 13 Jul 2007 07:55:44 -0400 ·
quoted from Thomas Kaehn
On Friday 13 July 2007 07:35, Thomas Kaehn wrote:
On Fri, Jul 13, 2007 at 12:49:22PM +0200, Henrik Stoerner wrote:
As for the diamond-shaped graph - yes, this is quite puzzling.
I've had a couple of other reports (see e.g. this thread:
http://www.hobbitmon.com/hobbiton/2005/10/msg00332.html).
We haven't been able to figure out why this happens, the data
that goes into the RRD file look sane.
The data in the rrd file looks strange however when dumped using
rrdtool. So every other value is different.
Would this somehow be linked to the ping graphs I see that form 'ramps' ? Does anyone else see these 'ramps' ? Most of my host ping times show the same pattern. So this would define the problem to be in Hobbit, or in my network ;) The BigBrother server, running in parallel with Hobbit, doesn't show this pattern. I am using the hobbitping tool. The small home hobbit server, I run, doesn't show this pattern 'ramp' pattern. 
You can see a sample graph at, http://jentoo.homedns.org:8080/pub/download/pingtimes.png

Thanks,
 ~Steve
list Thomas Kaehn · Mon, 16 Jul 2007 13:16:45 +0200 ·
Hi,
quoted from S Aiello

On Fri, Jul 13, 2007 at 07:55:44AM -0400, user-ce96540ed38f@xymon.invalid wrote:
On Friday 13 July 2007 07:35, Thomas Kaehn wrote:
On Fri, Jul 13, 2007 at 12:49:22PM +0200, Henrik Stoerner wrote:
As for the diamond-shaped graph - yes, this is quite puzzling.
I've had a couple of other reports (see e.g. this thread:
http://www.hobbitmon.com/hobbiton/2005/10/msg00332.html).
We haven't been able to figure out why this happens, the data
that goes into the RRD file look sane.
The data in the rrd file looks strange however when dumped using
rrdtool. So every other value is different.
Would this somehow be linked to the ping graphs I see that form 'ramps' ? Does 
anyone else see these 'ramps' ? Most of my host ping times show the same 
pattern. So this would define the problem to be in Hobbit, or in my 
network ;) The BigBrother server, running in parallel with Hobbit, doesn't 
show this pattern. I am using the hobbitping tool. The small home hobbit 
server, I run, doesn't show this pattern 'ramp' pattern. 

You can see a sample graph at, 
http://jentoo.homedns.org:8080/pub/download/pingtimes.png
this could be a similar problem. I've seen that the bbtest graph
corresponds to the network tests showing a wrong graph. Maybe the
problem is caused by bbtest-net?

Please compare:

http://www.westend.com/bbtest.png

http://www.westend.com/pop.png

Is there any possibility to debug this problem?
quoted from Thomas Kaehn

Ciao,
Thomas
-- 
Thomas Kähn                   WESTEND GmbH  |  Internet-Business-Provider
Technik                       CISCO Systems Partner - Authorized Reseller
                              Im Süsterfeld 6          Tel 0241/701333-18
user-02a72cb3f725@xymon.invalid                D-52072 Aachen              Fax 0241/911879
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Die Gesellschaft ist eingetragen im Handelsregister Aachen unter HRB 7608
Geschäftsführer:           Thomas Neugebauer, Thomas Heller, Michael Kolb
list Thomas Kaehn · Wed, 18 Jul 2007 10:20:57 +0200 ·
Hi,
quoted from Thomas Kaehn

On Mon, Jul 16, 2007 at 01:16:45PM +0200, Thomas Kaehn wrote:
On Fri, Jul 13, 2007 at 07:55:44AM -0400, user-ce96540ed38f@xymon.invalid wrote:
On Friday 13 July 2007 07:35, Thomas Kaehn wrote:
On Fri, Jul 13, 2007 at 12:49:22PM +0200, Henrik Stoerner wrote:
As for the diamond-shaped graph - yes, this is quite puzzling.
I've had a couple of other reports (see e.g. this thread:
http://www.hobbitmon.com/hobbiton/2005/10/msg00332.html).
We haven't been able to figure out why this happens, the data
that goes into the RRD file look sane.
this could be a similar problem. I've seen that the bbtest graph
corresponds to the network tests showing a wrong graph. Maybe the
problem is caused by bbtest-net?

Please compare:
http://www.westend.com/bbtest.png
http://www.westend.com/pop.png
BTW, I've moved the hobbit installation to a different system and
the graphs look normal now. Neither bbtest nor the different
network tests show the "diamonds" despite Hobbit and rrd versions
are the same.
quoted from Thomas Kaehn

Ciao,
Thomas
-- 
Thomas Kähn                   WESTEND GmbH  |  Internet-Business-Provider
Technik                       CISCO Systems Partner - Authorized Reseller
                              Im Süsterfeld 6          Tel 0241/701333-18
user-02a72cb3f725@xymon.invalid                D-52072 Aachen              Fax 0241/911879
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Die Gesellschaft ist eingetragen im Handelsregister Aachen unter HRB 7608
Geschäftsführer:           Thomas Neugebauer, Thomas Heller, Michael Kolb
list Stef Coene · Thu, 26 Jul 2007 20:58:51 +0200 ·
quoted from Thomas Kaehn
On Friday 13 July 2007, Thomas Kaehn wrote:
Hi,

I've set up a hobbit server to monitor a couple of systems.

However the network test graphs from exactly one system are looking
quite strange:

http://www.westend.com/pop3-1.png
http://www.westend.com/pop3-2.png		(zoomed in view)

According to this graph pop3 is answering always within zero seconds (I
can't imagine this). And the response time of pop3s is alternating in
such specific way that rrd draws triangles.

I've already deleted the rrd files, but the effect remains the same.

The system is running Debian 4.0 (librrd2 version 1.2.15-0.3). Has
anybody seen such strange effects before? All other systems and even
other services on the same system are looking reasonable.
Today, I noticed the same problem.  I have 2 hobbit servers: AIX with 
rrdtool-1.2.10-2 and a linux box with 1.2.15-0.3ubuntu1.  The AIX box is ok, 
the linux box shows the same trends.
I only see this in the http graphs.  Not in the ssh graphs.

Maybe a problem with version 1.2.15 ?  


Stef
list Stef Coene · Thu, 26 Jul 2007 21:47:50 +0200 ·
On Thursday 26 July 2007, Stef Coene wrote:
Maybe a problem with version 1.2.15 ?
Same problem on aix with rrd version 1.2.11-0.6ubuntu1.


Stef