Graphs not showing 🔗 link

Hello,

my previous post was mangled because there were some snippets of HTML in it. Therefore the message is posted again, this time without HTML.


the status of audio streams through an Open Digital Radio multiplexer is monitored in Xymon. A Perl script retrieves the status and statistics from the multiplexer, and sent them to Xymon. The statistics are to be shown in graphs. However, while the RR databases are build, no graphs are shown.

I am using debian 8.6 with xymon 4.3.17. (An update to version 4.3.27 failed, as the configure script does not recognise rrdtool 1.4.8, resulting in a version of xymon which does not support trend graphs.) A perl script retrieves the status of (the input channels of) the multiplexer, and sends the message to xymon. The statistics are included in the format which is also used by devmon. The last part of the status message of test odr_mux contains the following as HTML comment:

  linecount=2
DEVMON RRD: odr 0 0
DS:PeakLeft:GAUGE:600:-100:100 DS:PeakRight:GAUGE:600:-100:100 \
DS:Underrun:DERIVE:600:0:U DS:Overrun:DERIVE:600:0:U \ DS:BufferMin:GAUGE:600:-1:U DS:BufferMax:GAUGE:600:0:U
sub-ozo -90:-90:176972:0:-1:0
sub-urk -90:-90:176972:0:-1:0

In xymonserver.cfg two lines are adapted:

TEST2RRD=".... ,odr_mux=devmon"
GRAPHS=" .... ,odr_mux::1"

The statistics are entered in RRD's:

root at debian:/var/lib/xymon/rrd/OzoNop# ls -l odr*

-rw-r--r-- 1 xymon xymon 114560 Jan  8 19:04 odr.sub-ozo.rrd
-rw-r--r-- 1 xymon xymon 114560 Jan  8 19:04 odr.sub-urk.rrd

root at debian:/var/lib/xymon/rrd/OzoNop#

The graph definition is:

[odr_mux]
      FNPATTERN ^odr\.(.+)\.rrd$
      TITLE , Frame loss rate
      YAXIS Rate [/s]

      DEF:ur at RRDIDX@=@RRDFN@:Underrun:AVERAGE
      DEF:or at RRDIDX@=@RRDFN@:Overrun:AVERAGE
      LINE1:ur at RRDIDX@#FF0000:@RRDPARAM@ underrun
      GPRINT:ur at RRDIDX@:MIN:Min \: %5.1lf %s
      GPRINT:ur at RRDIDX@:MAX:Max \: %5.1lf %s
      GPRINT:ur at RRDIDX@:AVERAGE:Avg \: %5.1lf %s
      GPRINT:ur at RRDIDX@:LAST:Cur \: %5.1lf %s\n
      LINE1:or at RRDIDX@#00FF00:@RRDPARAM@  overrun
      GPRINT:or at RRDIDX@:MIN:Min \: %5.1lf %s
      GPRINT:or at RRDIDX@:MAX:Max \: %5.1lf %s
      GPRINT:or at RRDIDX@:AVERAGE:Avg \: %5.1lf %s
      GPRINT:or at RRDIDX@:LAST:Cur \: %5.1lf %s\n

The web page of this test shows the two tables, but no graphs. Only the magnifying glasses, which should be on the right of a graph, are shown. When clicking on the magnifying glass, an empty page is shown. The source code of this page is two lines long, the first one specifying the title to be "Invalid request", the second on showing an empty body.

Removing the graph definition results in a link to be displayed, and the magnifying glass shows an appropriate error message. Further experiments showed that if all multi-graph stuff is removed (that is, FNPATTERN and the @RRD...@ parameters) a single graph is shown. Extending the graph definition with FNPATTERN causes to problem to surface again.

The logfiles of xymon do not contain messages related to this problem, as far as I can see. Enabling debugging for xymond_rrd, the one spawn by the status channel reader, does not give any helpful information.

All the other graphs, including one multi-graph (test memory), of this host are displayed. The problem is only visible in test odr_mux.

Can anyone give me a hint on how to proceed to solve this issue?

Regards,
    Wim Nelis.

Are you sure data is making it into the RRD?  Try using rrdtool dump on the rrd and see if you get any data.


Scot Kreienkamp  | Senior Systems Engineer | La-Z-Boy Corporate
One La-Z-Boy Drive | Monroe, Michigan 48162 |  Office: XXX-XXX-XXXX |  |  Mobile: XXXXXXXXXX | Email: user-9678697f1438@xymon.invalid

-----Original Message-----
From: Xymon [mailto:xymon-bounces at xymon.com] On Behalf Of W.J.M.
Nelis
Sent: Monday, January 09, 2017 1:58 AM
To: xymon at xymon.com
Subject: [Xymon] Graphs not showing

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Hello Scot,

Are you sure data is making it into the RRD?  Try using rrdtool dump on the rrd and see if you get any data.

It has been verified that the data makes it into the RRD. Moreover, in the (test) case that a single graph was generated, two lines were shown, the underrun rate and the overrun rate. The statistics shown below the graph were all non-NaN.

I still don't understand this problem. The data is there in the RRD's, the databases are in the correct place, they are accessible and 'rrdtool dump` shows their content without error messages. If only one in stead of all graphs is requested, the requested graph is shown.

Thanks,
   Wim Nelis.

A suggestion since I do have many FNPATTERN definitions, but none like you
use. I think it has something to do with the \ character.

You can also use the EXFNPATTERN if you explicitly want to exclude similar
rrd-files. For example, I use to exclude the la_s_jvm from being parsed:

        FNPATTERN la_s_jv.(.*).rrd

   EXFNPATTERN la_s_jvm.(.*).rrd

Regards Peter

2017-01-09 14:30 GMT+01:00 W.J.M. Nelis <user-6956df205d63@xymon.invalid>:

Hello,

The problem was solved about a week ago. Xymon requires the name of the RRD's to start with the name of the test. In my case the test was called "odr_mux", while the Devmon header contained "DEVMON RRD: odr 0 0". The latter should have been "DEVMON RRD: odr_mux 0 0". After this change the graphs were shown by Xymon.

As noted earlier, there is no error message indicating a lack of files. Perhaps module showgraph.c, around line 1020 should be changed from:

         }
         rrddbs[rrddbcount].key = rrddbs[rrddbcount].rrdfn = rrddbs[rrddbcount].rrdparam = NULL;

         /* Sort them so the display looks prettier */
         qsort(&rrddbs[0], rrddbcount, sizeof(rrddb_t), rrd_name_compare);

into:

         }
         rrddbs[rrddbcount].key = rrddbs[rrddbcount].rrdfn = rrddbs[rrddbcount].rrdparam = NULL;
         if ( rrddbcount == 0 ) errormsg("invalid request - no matching RRDs found");

         /* Sort them so the display looks prettier */
         qsort(&rrddbs[0], rrddbcount, sizeof(rrddb_t), rrd_name_compare);

The variable wantsingle in function generate_graph in module showgraph.c was obviously true in my case, although a multi-graph was requested. It is not clear to me why this variable was set to true in my case.

Regards,
   Wim Nelis.