[Xymon] RRD - Aberrant Behavior Detection with Holt-Winters Forecasting

[Nico]

Hello

When devices are too overloaded; we got lot of gap in the graph and it is not very nice.

To avoid that, i would like to implement the abberrant behavior detection provided by RRDTOOL.

Following http://oss.oetiker.ch/rrdtool/doc/rrdcreate.en.html, i defined a new RRA in ~xymon/server/etc/rrddefinitions.cfg

[test_rrd]
        RRA:AVERAGE:0.5:1:576
        RRA:AVERAGE:0.5:6:576
        RRA:AVERAGE:0.5:24:576
        RRA:AVERAGE:0.5:288:576
        # RRA:HWPREDICT:<array length>:<alpha>:<beta>:<period>
        # enable RRAs for aberrant detection, 1 day seasonal store for 5 day
	RRA:HWPREDICT:1440:0.1:0.0035:288 <------ new entry

i got a simple test script running every 5 mn:

sh-3.00$ cat test_rrd.sh 
#!/bin/sh
HOSTNAME="test_device"
value=42
$BB $BBDISP  "status+200d $HOSTNAME.test_rrd green `date`
test: $value"


i got ncv conf in xymonserver.cfg, the graph is working fine with this basic definition:

[test_rrd]
         TITLE test RRD
         YAXIS value
         DEF:a=test_rrd.rrd:test:AVERAGE
         LINE2:a#00CC00:test value
         GPRINT:a:LAST: \: %5.1lf (cur)
         GPRINT:a:MAX: \: %5.1lf (max)
         GPRINT:a:MIN: \: %3.1lf (min)
         GPRINT:a:AVERAGE: \: %5.1lf (avg)\n

now, if i add the def:

        DEF:b=test_rrd.rrd:test:HWPREDICT

the graph is not showing anymore [even if i didn t use the new DEF on a LINE]  :(

if i dump the rrd i can see the RRA :

sh-3.00$ rrdtool dump /opt/xymon/data/rrd/test_device/test_rrd.rrd |grep HW
                <cf> HWPREDICT </cf>


any idea is welcome.

Thanks.

regards
Nico