[rrd-users] Updates lost using rrdcached?

[Dirk]

Hello,

I notice some updated values are not always written to my rrdfile by
rrdcached. The updates do however appear in in the rrdcached daemon
journal:

Any idea what can be causing this behaviour or what I'm missing?


E.g. the update of time 1384516800 is not present in the rrdfile. The
updates before and after are:

Journal Entries:
rrd.journal.1384512944.188647:wrote /var/rrd/0/2/8/test.rrd
rrd.journal.1384516544.283473:update /var/rrd/0/2/8/test.rrd
1384516440:3560054323:2684354508
rrd.journal.1384516544.283473:update /var/rrd/0/2/8/test.rrd
1384516800:3563798323:2684354508
rrd.journal.1384516544.283473:update /var/rrd/0/2/8/test.rrd
1384516860:3564422323:2684354508
rrd.journal.1384516544.283473:update /var/rrd/0/2/8/test.rrd
1384516920:3565046167:2684354508
rrd.journal.1384516544.283473:update /var/rrd/0/2/8/test.rrd
1384517040:3566294167:2684354560
rrd.journal.1384516544.283473:wrote /var/rrd/0/2/8/test.rrd

rrdcached is started with: /opt/rrdtool-1.4.8/bin/rrdcached -j
/var/rrd -b /var/rrd -w 900 -z 1

Version RRDtool 1.4.8  Copyright 1997-2013 by Tobias Oetiker <tobi at oetiker.ch>
Compiled Oct 29 2013 08:33:45

Output of '/opt/rrdtool-1.4.8/bin/rrdtool dump /var/rrd/0/2/8/test.rrd'
<!-- 2013-11-15 12:48:00 CET / 1384516080 -->
<row><v>3.5563190720e+09</v><v>2.6843545600e+09</v></row>
<!-- 2013-11-15 12:49:00 CET / 1384516140 --> <row><v>NaN</v><v>NaN</v></row>
<!-- 2013-11-15 12:50:00 CET / 1384516200 --> <row><v>NaN</v><v>NaN</v></row>
<!-- 2013-11-15 12:51:00 CET / 1384516260 --> <row><v>NaN</v><v>NaN</v></row>
<!-- 2013-11-15 12:52:00 CET / 1384516320 --> <row><v>NaN</v><v>NaN</v></row>
<!-- 2013-11-15 12:53:00 CET / 1384516380 --> <row><v>NaN</v><v>NaN</v></row>
<!-- 2013-11-15 12:54:00 CET / 1384516440 -->
<row><v>3.5600543230e+09</v><v>2.6843545080e+09</v></row>
<!-- 2013-11-15 12:55:00 CET / 1384516500 --> <row><v>NaN</v><v>NaN</v></row>
<!-- 2013-11-15 12:56:00 CET / 1384516560 --> <row><v>NaN</v><v>NaN</v></row>
<!-- 2013-11-15 12:57:00 CET / 1384516620 --> <row><v>NaN</v><v>NaN</v></row>
<!-- 2013-11-15 12:58:00 CET / 1384516680 --> <row><v>NaN</v><v>NaN</v></row>
<!-- 2013-11-15 12:59:00 CET / 1384516740 --> <row><v>NaN</v><v>NaN</v></row>
<!-- 2013-11-15 13:00:00 CET / 1384516800 --> <row><v>NaN</v><v>NaN</v></row>
<!-- 2013-11-15 13:01:00 CET / 1384516860 -->
<row><v>3.5644223230e+09</v><v>2.6843545080e+09</v></row>
<!-- 2013-11-15 13:02:00 CET / 1384516920 -->
<row><v>3.5650461670e+09</v><v>2.6843545080e+09</v></row>
<!-- 2013-11-15 13:03:00 CET / 1384516980 --> <row><v>NaN</v><v>NaN</v></row>
<!-- 2013-11-15 13:04:00 CET / 1384517040 --> <row><v>NaN</v><v>NaN</v></row>
<!-- 2013-11-15 13:05:00 CET / 1384517100 -->
<row><v>3.5672366150e+09</v><v>2.6843545080e+09</v></row>
<!-- 2013-11-15 13:06:00 CET / 1384517160 -->
<row><v>3.5678605630e+09</v><v>2.6843545080e+09</v></row>
<!-- 2013-11-15 13:07:00 CET / 1384517220 -->
<row><v>3.5685118630e+09</v><v>2.6843545080e+09</v></row>
<!-- 2013-11-15 13:08:00 CET / 1384517280 -->
<row><v>3.5694754230e+09</v><v>2.6843545080e+09</v></row>
<!-- 2013-11-15 13:09:00 CET / 1384517340 -->
<row><v>3.5700986470e+09</v><v>2.6843544560e+09</v></row>


The RDD file is created with perl:
push @q_array, "/var/rrd/0/2/8/test.rrd";
push @q_array, "--step=60";
push @q_array, "--start=1352985960";
push @q_array, "DS:d_tbs:GAUGE:60:0:U";
push @q_array, "DS:u_tbs:GAUGE:60:0:U";
push @q_array, "RRA:LAST:0.99999:1:1000";    # 16 hours @ 1min
push @q_array, "RRA:LAST:0.99999:60:1000";     # 41.6 days @ 1h
push @q_array, "RRA:LAST:0.99999:1440:1000";     # 2.74 year @ 1d
push @q_array, "RRA:MAX:0.99999:1:1000";         # 16 hours @ 1min
push @q_array, "RRA:MAX:0.99999:60:1000";      # 41.6 days @ 1h
push @q_array, "RRA:MAX:0.99999:1440:1000";     # 2.74 year @ 1d
push @q_array, "RRA:MIN:0.99999:1:1000";           # 16 hours @ 1min
push @q_array, "RRA:MIN:0.99999:60:1000";        # 41.6 days @ 1h
push @q_array, "RRA:MIN:0.99999:1440:1000";     # 2.74 year @ 1d
RRDs::create(@t_array);
(no errors occur)


Kind regards,
Dirk