With any stable or unstable net-analyzer/rrdtool >1.4.8-r1, mrtg-2.17.4 or 2.17.4-r1 fails to generate any graphs. Apache logs the following error: [Sun Mar 18 14:04:39.866602 2018] [cgi:error] [pid 19784:tid 140158795384576] [client 10.24.32.10:50654] AH01215: Undefined subroutine &RRDs::graph called at /var/www/mrtg/mrtg-rrd.cgi line 451.: /var/www/mrtg/mrtg-rrd.cgi, referer: https://www.caerllewys.net/mrtg2/ If net-analyzer/rrdtool is rolled back to 1.4.8-r1, mrtg works again. It seems perhaps there is a problem with the export of RRDs::graph, or possibly with all of the exports from RRDs?
Note: mrtg still apparently *gathers and records* the data even when graphing is not working, it just fails to graph it. When rrdtool is rolled back to a working version, there is no data gap. Also, scratch the speculation about RRDs::graph not being exported correctly, because my own upswatch tool also used rrdtool, also calls RRDs::graph, and appears to work fine. So I am mystified as to why mrtg thinks RRDs::graph is undefined. mrtg usage: my @rv = RRDs::graph($file, '-s', "-$back", @local_args, @{$target->{args}}, "VRULE:$oldsec#ff0000", "VRULE:$seconds#ff0000", @local_args_end); Fails. upswatch usage: RRDs::graph($hourloadgraph, "--title", "UPS Load (last 2 hours)", "--start", time()-7200, "--lower-limit", 0, "--height", 300, "--x-grid", "MINUTE:5:MINUTE:15:MINUTE:15:0:%R", "--right-axis", "1:0", "--slope-mode", "DEF:load=$rrd_file:load:LAST", "CDEF:low=load,0,GE,load,0,IF", "CDEF:med=load,50,GE,load,0,IF", "CDEF:high=load,80,GE,load,0,IF", "CDEF:crit=load,100,GT,load,0,IF", "AREA:low#00FF00:Low (<50)", "AREA:med#00FFFF:Medium (<80)", "AREA:high#FFFF00:High (>80)", "AREA:crit#FF0000:Critical (>100)", "LINE1:load#000000") || upslog("$hourloadgraph update failed!\n"); Works. Really not sure what's going on here. The rrdtool version dependency makes it look like an rrdtool problem, but ... upswatch works whichever rrdtool version is installed, right up to ~1.7.0. Which suggests it's an mrtg problem.
Note: Upstream issue #10 opened.
PLEASE DISREGARD. Upon closer examination I have realized that the problem is not with mrtg, it is with mrtg-rrd.cgi, which is NOT part of mrtg and is from a separate source. (I still don't know why it's failing, but.... it's not a net-analyzer/mrtg problem.)
