SYNOPSIS

use Smokeping::RRDtools;
use RRDs;
my $file = '/path/to/file.rrd';
# get the create arguments that $file was created with
my $create = Smokeping::RRDtools::info2create($file);
# use them to create a new file
RRDs::create('/path/to/file2.rrd', @$create);
# or compare them against another create list
my @create = ('--step', 60, 'DS:ds0:GAUGE:120:0:U', 'RRA:AVERAGE:0.5:1:1008');
my ($fatal, $comparison) = Smokeping::RRDtools::compare($file, \@create);
print "Fatal: " if $fatal;
print "Create arguments didn't match: $comparison\n" if $comparison;
Smokeping::RRDtools::tuneds($file, \@create);

DESCRIPTION

This module offers three functions, "info2create", "compare" and "tuneds". The first can be used to recreate the arguments that an RRD file was created with. The second checks if an RRD file was created with the given arguments. The thirds tunes the DS parameters according to the supplied create string.

The function "info2create" must be called with one argument: the path to the interesting RRD file. It will return an array reference of the argument list that can be fed to "RRDs::create". Note that this list will never contain the "start" parameter, but it will contain the "step" parameter.

The function "compare" must be called with two arguments: the path to the interesting RRD file, and a reference to an argument list that could be fed to "RRDs::create". The function will then simply compare the result of "info2create" with this argument list. It will return an array of two values: "(fatal, text)" where "fatal" is 1 if it found a fatal difference, and 0 if not. The "text" will contain an error message if "fatal == 1" and a possible warning message if "fatal == 0". If "fatal == 0" and "text" is "undef", all the arguments matched.

Note that if there is a "start" parameter in the argument list, "compare" disregards it. If "step" isn't specified, "compare" will use the "rrdtool" default of 300 seconds. "compare" ignores non-matching DS parameters since "tuneds" will fix them.

"tuneds" talks on stderr about the parameters it fixes.

NOTES

This module is not particularly specific to Smokeping, it is just distributed with it.

COPYRIGHT

Copyright (c) 2005 by Niko Tyni.

AUTHOR

Niko Tyni <[email protected]>

LICENSE

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.