#1283 assigned defect

Combined graphs appear to be broken

Reported by: cbiedl Owned by: snide
Priority: highest Milestone: Munin 2.0.15
Component: master Version: 2.0.6
Severity: blocker Keywords:
Cc:

Description

Hello,

trying to create combined graphs as described in
http://munin-monitoring.org/wiki/Combined_examples
I found a lot of error messages but no graphs were created.
We've been discussing this in IRC.

The reproducer (munin.conf) sums the uptimes of two hosts:

[host-a]

address 127.0.0.1
use_node_name yes

[host-b]

address 172.23.X.X
use_node_name yes

uptimes.update no
uptimes.graph_args --base 1000 -l 0
uptimes.graph_category System
uptimes.graph_title uptimes sum
uptimes.graph_order \

combined

uptimes.combined.sum \

host-a:uptime.uptime \
host-b:uptime.uptime

uptimes.combined.label Sum uptime

In Debian wheezy (munin 2.0.6) in default graph_strategy mode (cron),
I find in munin-graph.log:

2012/12/09 17:41:27 Starting munin-graph
2012/12/09 17:41:27 [ERROR] filename is empty for $VAR1 = {

'#%#name' => 'z1_0',
'cdef' => 'z1_0,UN,0,z1_0,IF',
'graph' => 'no',
'label' => 'z1_0'

};
, host-a:uptime.uptime
2012/12/09 17:41:27 [INFO] Looking into drawing /var/cache/munin/www/host-b/host-b/uptimes-day.png
2012/12/09 17:41:27 [RRD ERROR] Unable to graph /var/cache/munin/www/host-b/host-b/uptimes-day.png : invalid rpn expression in: az1_1,UN,0,az1_1,IF,az1_0,ADDNAN
2012/12/09 17:41:27 [RRD ERROR] rrdtool 'graph' '/var/cache/munin/www/host-b/host-b/uptimes-day.png' \

'--title' \

(...)

'1355070900'

2012/12/09 17:41:27 [INFO] Graphed service host-b;host-b:uptimes (0.00 sec for 1 graphs)
2012/12/09 17:41:27 Munin-graph finished (0.00 sec)
2012/12/09 17:41:27 [WARNING] Could not draw graph "/var/cache/munin/www/host-b/host-b/uptimes-day.png": /var/cache/munin/www/host-b/host-b/uptimes-day.png
2012/12/09 17:41:27 X-Munin-Request: 400/0
2012/12/09 17:41:27 [PERL WARNING] Use of uninitialized value $epoch in gmtime at /usr/share/munin/munin-graph line 205, <GEN1> line 401.
2012/12/09 17:41:27 [PERL WARNING] Use of uninitialized value $mtime_epoch in modulus (%) at /usr/share/munin/munin-graph line 192, <GEN1> line 401.
2012/12/09 17:41:27 [PERL WARNING] Use of uninitialized value $mtime_epoch in subtraction (-) at /usr/share/munin/munin-graph line 192, <GEN1> line 401.
2012/12/09 17:41:27 [PERL WARNING] Use of uninitialized value in concatenation (.) or string at /usr/share/munin/munin-graph line 166, <GEN1> line 401.

Using cgi doesn't help either.

In Debian squeeze (munin 1.4.3) this appears to be broken, too:

2012/12/09 17:40:20 [PERL WARNING] Use of uninitialized value in subroutine entry at /usr/share/perl5/Munin/Master/GraphOld.pm line 757.
2012/12/09 17:40:20 [PERL WARNING] Use of uninitialized value $filename in concatenation (.) or string at /usr/share/perl5/Munin/Master/GraphOld.pm line 774.
2012/12/09 17:40:20 [PERL WARNING] Use of uninitialized value $filename in concatenation (.) or string at /usr/share/perl5/Munin/Master/GraphOld.pm line 783.
2012/12/09 17:40:20 [PERL WARNING] Use of uninitialized value $filename in concatenation (.) or string at /usr/share/perl5/Munin/Master/GraphOld.pm line 785.
2012/12/09 17:40:20 [PERL WARNING] Use of uninitialized value $filename in concatenation (.) or string at /usr/share/perl5/Munin/Master/GraphOld.pm line 786.
2012/12/09 17:40:20 [RRD ERROR] Unable to graph /var/cache/munin/www/host-b/host-b/uptimes-month.png : opening : No such file or directory
2012/12/09 17:40:20 [RRD ERROR] Unable to graph /var/cache/munin/www/host-b/host-b/uptimes-week.png : opening
: No such file or directory

According to some diagnostics done via IRC the problem is munin cannot
find the RRD files from other hosts, in other words, combining data
from the same host like in

[host-b]
(...)
uptimes.combined.sum \

host-b:uptime.uptime \
host-b:uptime.uptime

works as expected.

This is a serious issue although appearently this breakage was
unnoticed for quite some time. Or it's simply combined graphs don't
work that way. In that case, the wiki page needs an update and more
simple examples than just that big complex one. Let me know if I
should provide some.

Christoph

Change History (5)

comment:1 Changed at 2012-12-12T08:14:18+01:00 by cbiedl

FWIW, this is still present in 2.0.9 as uploaded to Debian
experimental yesterday.

comment:2 Changed at 2013-04-01T14:30:33+02:00 by snide

  • Milestone set to Munin 2.0.13
  • Owner changed from nobody to snide
  • Status changed from new to assigned

comment:3 Changed at 2013-09-30T08:34:42+02:00 by pprkut

I'm still seeing this behaviour with 2.0.17 on CentOS 6. Is there maybe an update on the status of a fix?

comment:4 Changed at 2013-10-15T08:13:53+02:00 by jhuhta

I worked around this bug by pretending that there's no hyphens in the hostnames used in combined graphs. Using 2.0.17 on CentOS 5.

comment:5 Changed at 2013-11-12T17:16:54+01:00 by emilio@…

confirm the same bug: sums (or stacks) of hostnames with a "-" (like "host-one") make trigger this problem in munin-graph

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