[rrd-users] rrdtool resize corrupts timestamps in both 1.3.9 and 1.4.7

[Jo Rhett]

I found that doing a resize on an rrd file caused a total loss of data with rrdtool 1.3.9 which is bundled with zenoss 3.2.1 on CentOS 5.  Investigating with the tools found that the data was there, but the timestamps were corrupt.

So I grabbed rrdtool 1.4.7 and tried to use it and found that it has the same problem on CentOS 5.

$ rrdtool dump testfile.rrd | head -40
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE rrd SYSTEM "http://oss.oetiker.ch/rrdtool/rrdtool.dtd">
<!-- Round Robin Database Dump --><rrd>	<version> 0003 </version>
	<step> 15 </step> <!-- Seconds -->
	<lastupdate> 1342133281 </lastupdate> <!-- 2012-07-12 15:48:01 PDT -->

	<ds>
		<name> ds0 </name>
		<type> COUNTER </type>
		<minimal_heartbeat> 45 </minimal_heartbeat>
		<min> NaN </min>
		<max> 1.0000000000e+04 </max>

		<!-- PDP Status -->
		<last_ds> 5585260819 </last_ds>
		<value> 5.2688224977e+02 </value>
		<unknown_sec> 0 </unknown_sec>
	</ds>

<!-- Round Robin Archives -->	<rra>
		<cf> AVERAGE </cf>
		<pdp_per_row> 1 </pdp_per_row> <!-- 15 seconds -->

		<params>
		<xff> 5.0000000000e-01 </xff>
		</params>
		<cdp_prep>
			<ds>
			<primary_value> 5.0500416920e+02 </primary_value>
			<secondary_value> 5.0571394032e+02 </secondary_value>
			<value> NaN </value>
			<unknown_datapoints> 0 </unknown_datapoints>
			</ds>
		</cdp_prep>
		<database>
			<!-- 2012-07-12 13:18:15 PDT / 1342124295 --> <row><v> 5.2835238201e+02 </v></row>
			<!-- 2012-07-12 13:18:30 PDT / 1342124310 --> <row><v> 5.2950058206e+02 </v></row>
			<!-- 2012-07-12 13:18:45 PDT / 1342124325 --> <row><v> 5.3706333105e+02 </v></row>
			<!-- 2012-07-12 13:19:00 PDT / 1342124340 --> <row><v> 5.2656011537e+02 </v></row>
			<!-- 2012-07-12 13:19:15 PDT / 1342124355 --> <row><v> 5.0348379147e+02 </v></row>

$ rrdtool resize testfile.rrd 0 GROW 1416

$ rrdtool dump resize.rrd | head -40
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE rrd SYSTEM "http://oss.oetiker.ch/rrdtool/rrdtool.dtd">
<!-- Round Robin Database Dump --><rrd>	<version> 0003 </version>
	<step> 15 </step> <!-- Seconds -->
	<lastupdate> 4048795654275216693 </lastupdate> <!-- -547790155-01-11136 05:31:33 PST -->

	<ds>
		<name> ds0 </name>
		<type> COUNTER </type>
		<minimal_heartbeat> 45 </minimal_heartbeat>
		<min> NaN </min>
		<max> 1.0000000000e+04 </max>

		<!-- PDP Status -->
		<last_ds>  </last_ds>
		<value> 0.0000000000e+00 </value>
		<unknown_sec> 0 </unknown_sec>
	</ds>

<!-- Round Robin Archives -->	<rra>
		<cf> AVERAGE </cf>
		<pdp_per_row> 1 </pdp_per_row> <!-- 15 seconds -->

		<params>
		<xff> 5.0000000000e-01 </xff>
		</params>
		<cdp_prep>
			<ds>
			<primary_value> 0.0000000000e+00 </primary_value>
			<secondary_value> 0.0000000000e+00 </secondary_value>
			<value> 0.0000000000e+00 </value>
			<unknown_datapoints> 0 </unknown_datapoints>
			</ds>
		</cdp_prep>
		<database>
			<!-- -547790155-01-11136 21:07:45 PST / 892845857 --> <row><v> NaN </v></row>
			<!-- -547790155-01-11136 21:08:00 PST / 892845872 --> <row><v> NaN </v></row>
			<!-- -547790155-01-11136 21:08:15 PST / 892845887 --> <row><v> NaN </v></row>
			<!-- -547790155-01-11136 21:08:30 PST / 892845902 --> <row><v> NaN </v></row>
			<!-- -547790155-01-11136 21:08:45 PST / 892845917 --> <row><v> NaN </v></row>

Let's find the first value that was in the old file.

$ rrdtool dump tmp.0.resize.rrd | grep 5.28352
			<!-- -547790155-01-11098 03:01:15 PST / 892867067 --> <row><v> 5.2835238201e+02 </v></row>

Hm. That's a way bit different timestamp than this record
			<!-- 2012-07-12 13:18:15 PDT / 1342124295 --> <row><v> 5.2835238201e+02 </v></row>

-- 
Jo Rhett
Net Consonance : net philanthropy to improve open source and internet projects.



-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.oetiker.ch/pipermail/rrd-users/attachments/20120712/2ee18a47/attachment.htm