Ticket #8 (closed defect: fixed)

Opened 6 years ago

Last modified 5 years ago

HWPREDICT misbehaves on Linux

Reported by: shadow Owned by: oetiker
Priority: minor Milestone:
Component: rrd_update Version:
Keywords: HWPREDICT NaN failure Cc:

Description

RRDtool on Linux/x86 gives unexpected Holt-Winters results. Tested on 1.2.11 and 1.2.12.

Example:

rrdtool create x.rrd -s 86400 -b 962496000 DS:ds0:GAUGE:86400:U:U RRA:AVERAGE:.5:1:10 RRA:HWPREDICT:10:.5:.1:2

rrdtool updatev x.rrd 962582400:1 962668800:2 962755200:3 962841600:4 962928000:5 963014400:6 963100800:7 963187200:8 963273600:9

Solaris/x86 (various gcc releases, incl. 2.95.3, 3.[34].x): 

[962582400]RRA[HWPREDICT][1]DS[ds0] = NaN
[962668800]RRA[HWPREDICT][1]DS[ds0] = NaN
[962755200]RRA[HWPREDICT][1]DS[ds0] = 1.0000000000e+00
[962841600]RRA[HWPREDICT][1]DS[ds0] = 3.1000000000e+00
[962928000]RRA[HWPREDICT][1]DS[ds0] = 3.1950000000e+00
[963014400]RRA[HWPREDICT][1]DS[ds0] = 5.0577500000e+00
[963100800]RRA[HWPREDICT][1]DS[ds0] = 5.5374875000e+00
[963187200]RRA[HWPREDICT][1]DS[ds0] = 7.1335443750e+00
[963273600]RRA[HWPREDICT][1]DS[ds0] = 7.8218987187e+00

[962582400]RRA[SEASONAL][1]DS[ds0] = 0.0000000000e+00
[962668800]RRA[SEASONAL][1]DS[ds0] = 1.0000000000e+00
[962755200]RRA[SEASONAL][1]DS[ds0] = 5.0000000000e-01
[962841600]RRA[SEASONAL][1]DS[ds0] = 1.2250000000e+00
[962928000]RRA[SEASONAL][1]DS[ds0] = 9.5125000000e-01
[963014400]RRA[SEASONAL][1]DS[ds0] = 1.4605625000e+00
[963100800]RRA[SEASONAL][1]DS[ds0] = 1.3168781250e+00
[963187200]RRA[SEASONAL][1]DS[ds0] = 1.6771764063e+00
[963273600]RRA[SEASONAL][1]DS[ds0] = 1.6114034453e+00

[962582400]RRA[DEVSEASONAL][1]DS[ds0] = NaN
[962668800]RRA[DEVSEASONAL][1]DS[ds0] = NaN
[962755200]RRA[DEVSEASONAL][1]DS[ds0] = 2.0000000000e+00
[962841600]RRA[DEVSEASONAL][1]DS[ds0] = 9.0000000000e-01
[962928000]RRA[DEVSEASONAL][1]DS[ds0] = 1.9025000000e+00
[963014400]RRA[DEVSEASONAL][1]DS[ds0] = 9.2112500000e-01
[963100800]RRA[DEVSEASONAL][1]DS[ds0] = 1.6825062500e+00
[963187200]RRA[DEVSEASONAL][1]DS[ds0] = 8.9379031250e-01
[963273600]RRA[DEVSEASONAL][1]DS[ds0] = 1.4303037656e+00

[962582400]RRA[DEVPREDICT][1]DS[ds0] = NaN
[962668800]RRA[DEVPREDICT][1]DS[ds0] = NaN
[962755200]RRA[DEVPREDICT][1]DS[ds0] = NaN
[962841600]RRA[DEVPREDICT][1]DS[ds0] = NaN
[962928000]RRA[DEVPREDICT][1]DS[ds0] = 2.0000000000e+00
[963014400]RRA[DEVPREDICT][1]DS[ds0] = 9.0000000000e-01
[963100800]RRA[DEVPREDICT][1]DS[ds0] = 1.9025000000e+00
[963187200]RRA[DEVPREDICT][1]DS[ds0] = 9.2112500000e-01
[963273600]RRA[DEVPREDICT][1]DS[ds0] = 1.6825062500e+00

Linux/x86 (ditto): 

[962582400]RRA[HWPREDICT][1]DS[ds0] = NaN
[962668800]RRA[HWPREDICT][1]DS[ds0] = NaN
[962755200]RRA[HWPREDICT][1]DS[ds0] = NaN
[962841600]RRA[HWPREDICT][1]DS[ds0] = NaN
[962928000]RRA[HWPREDICT][1]DS[ds0] = NaN
[963014400]RRA[HWPREDICT][1]DS[ds0] = NaN
[963100800]RRA[HWPREDICT][1]DS[ds0] = NaN
[963187200]RRA[HWPREDICT][1]DS[ds0] = NaN
[963273600]RRA[HWPREDICT][1]DS[ds0] = NaN

[962582400]RRA[SEASONAL][1]DS[ds0] = 0.0000000000e+00
[962668800]RRA[SEASONAL][1]DS[ds0] = 1.0000000000e+00
[962755200]RRA[SEASONAL][1]DS[ds0] = 2.0000000000e+00
[962841600]RRA[SEASONAL][1]DS[ds0] = 3.0000000000e+00
[962928000]RRA[SEASONAL][1]DS[ds0] = 4.0000000000e+00
[963014400]RRA[SEASONAL][1]DS[ds0] = 5.0000000000e+00
[963100800]RRA[SEASONAL][1]DS[ds0] = 6.0000000000e+00
[963187200]RRA[SEASONAL][1]DS[ds0] = 7.0000000000e+00
[963273600]RRA[SEASONAL][1]DS[ds0] = 8.0000000000e+00

[962582400]RRA[DEVSEASONAL][1]DS[ds0] = NaN
[962668800]RRA[DEVSEASONAL][1]DS[ds0] = NaN
[962755200]RRA[DEVSEASONAL][1]DS[ds0] = NaN
[962841600]RRA[DEVSEASONAL][1]DS[ds0] = NaN
[962928000]RRA[DEVSEASONAL][1]DS[ds0] = NaN
[963014400]RRA[DEVSEASONAL][1]DS[ds0] = NaN
[963100800]RRA[DEVSEASONAL][1]DS[ds0] = NaN
[963187200]RRA[DEVSEASONAL][1]DS[ds0] = NaN
[963273600]RRA[DEVSEASONAL][1]DS[ds0] = NaN

[962582400]RRA[DEVPREDICT][1]DS[ds0] = NaN
[962668800]RRA[DEVPREDICT][1]DS[ds0] = NaN
[962755200]RRA[DEVPREDICT][1]DS[ds0] = NaN
[962841600]RRA[DEVPREDICT][1]DS[ds0] = NaN
[962928000]RRA[DEVPREDICT][1]DS[ds0] = NaN
[963014400]RRA[DEVPREDICT][1]DS[ds0] = NaN
[963100800]RRA[DEVPREDICT][1]DS[ds0] = NaN
[963187200]RRA[DEVPREDICT][1]DS[ds0] = NaN
[963273600]RRA[DEVPREDICT][1]DS[ds0] = NaN

Change History

comment:1 Changed 6 years ago by oetiker

  • Status changed from new to assigned

comment:2 Changed 6 years ago by oetiker

The problem seems only to occur when running several updates in one round ... when calling rrdtool updatev once for each number then all is fine. This explains why this problem went undetected for so long I guess.

comment:3 Changed 5 years ago by oetiker

  • Status changed from assigned to closed
  • Resolution set to fixed

this is fixed in 1.3dev with the mmap rewrite.

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