summaryrefslogtreecommitdiffstats
path: root/lib/Smokeping/RRDtools.pm
blob: 6fde06b6fe5ac987eedfc8234cdce76d4af09e0b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
package Smokeping::RRDtools;

=head1 NAME

Smokeping::RRDtools - Tools for RRD file handling

=head1 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);
 
=head1 DESCRIPTION

This module offers three functions, C<info2create>, C<compare> and
C<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 C<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 C<RRDs::create>.
Note that this list will never contain the C<start> parameter,
but it B<will> contain the C<step> parameter.

The function C<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 C<RRDs::create>. The function will then simply compare the result of
C<info2create> with this argument list. It will return an array of two values:
C<(fatal, text)> where  C<fatal> is 1 if it found a fatal difference, and 0 if not.
The C<text> will contain an error message if C<fatal == 1> and a possible warning 
message if C<fatal == 0>. If C<fatal == 0> and C<text> is C<undef>, all the
arguments matched.

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

C<tuneds> talks on stderr about the parameters it fixes.

=head1 NOTES

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

=head1 BUGS

Probably.

=head1 COPYRIGHT

Copyright (c) 2005 by Niko Tyni.

=head1 AUTHOR

Niko Tyni <ntyni@iki.fi>

=head1 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.

=head1 SEE ALSO

RRDs(3)

=cut

use strict;
use RRDs;

# take an RRD file and make a create list out of it
sub info2create {
	my $file = shift;
	my @create;
	# check for Perl version 5.8.0, it's buggy
	# no more v-strings 
        my $buggy_perl_version = 1 if abs($] - 5.008000) < .0000005;

	my $info = RRDs::info($file);
	my $error = RRDs::error;
	die("RRDs::info $file: ERROR: $error") if $error;
	die("$file: unknown RRD version: $info->{rrd_version}")
		unless $info->{rrd_version} eq '0001'
		or     $info->{rrd_version} eq '0003';
	my $cf = $info->{"rra[0].cf"};
	die("$file: no RRAs found?") 
		unless defined $cf;
	my @fetch = RRDs::fetch($file, $cf);
	$error = RRDs::error;
	die("RRDs::fetch $file $cf: ERROR: $error") if $error;
	my @ds = @{$fetch[2]};

	push @create, '--step', $info->{step};
	for my $ds (@ds) {
		my @s = ("DS", $ds);
		for (qw(type minimal_heartbeat min max)) {
			die("$file: missing $_ for DS $ds?")
				unless exists $info->{"ds[$ds].$_"}
                or $buggy_perl_version;
			my $val = $info->{"ds[$ds].$_"};
			push @s, defined $val ? $val : "U";
		}
		push @create, join(":", @s);
	}
	for (my $i=0; exists $info->{"rra[$i].cf"}; $i++) {
		my @s = ("RRA", $info->{"rra[$i].cf"});
		for (qw(xff pdp_per_row rows)) {
			die("$file: missing $_ for RRA $i")
				unless exists $info->{"rra[$i].$_"}
                or $buggy_perl_version;
			push @s, $info->{"rra[$i].$_"};
		}
		push @create, join(":", @s);
	}
	return \@create;
}

sub compare {
	my $file = shift;
	my $create = shift;
	my @create2 = @{info2create($file)};
	my @create = @$create; # copy because we change it
	# we don't compare the '--start' param
	if ($create[0] eq '--start') {
		shift @create;
		shift @create;
	}
	# special check for the optional 'step' parameter
	die("Internal error: didn't get the step parameter from info2create?")
		unless ("--step" eq shift @create2);
	my $step = shift @create2;
	my $step2;
	if ($create[0] eq '--step') {
		shift @create;
		$step2 = shift @create;
	} else {
		$step2 = 300; # default value
	}
	return (1, "Wrong value of step: $file has $step, create string has $step2")
		unless $step == $step2;
	
	my $dscount = grep /^DS/, @create;
	my $dscount2 = grep /^DS/, @create2;
	return (1, "Different number of data sources: $file has $dscount2, create string has $dscount")
		unless $dscount == $dscount2;
	my $rracount = grep /^RRA/, @create;
	my $rracount2 = grep /^RRA/, @create2;
	return (1, "Different number of RRAs: $file has $rracount2, create string has $rracount")
		unless $rracount == $rracount2;

	my $warning;
	while (my $arg = shift @create) {
		my $arg2 = shift @create2;
		my @ds = split /:/, $arg;
		my @ds2 = split /:/, $arg2;
		next if $ds[0] eq 'DS' and $ds[0] eq $ds2[0] and $ds[1] eq $ds2[1] and $ds[2] eq $ds2[2];
		if ($arg ne $arg2) {
			if ($ds[0] eq 'RRA' and $ds[0] eq $ds2[0] and $ds[1] eq $ds2[1]) {
				# non-fatal: CF is the same, but xff/steps/rows differ
				$warning .= "Different RRA parameters: $file has $arg2, create string has $arg";
			} else {
				return (1, "Different arguments: $file has $arg2, create string has $arg");
			}
		}
	}
	return (0, $warning);
}

sub tuneds {
        my $file = shift;
        my $create = shift;
        my @create2 = sort grep /^DS/, @{info2create($file)};
	my @create = sort grep /^DS/,  @$create;
	while (@create){
	       my @ds = split /:/, shift @create;
	       my @ds2 = split /:/, shift @create2;
	       next unless $ds[1] eq $ds2[1] and $ds[2] eq $ds[2];
	       if ($ds[3] ne $ds2[3]){
	       		warn "## Updating $file DS:$ds[1] heartbeat $ds2[3] -> $ds[3]\n";
	  	        RRDs::tune $file,"--hearbeat","$ds[1]:$ds[3]" unless $ds[3] eq $ds2[3];
	       }
	       if ($ds[4] ne $ds2[4]){
	       		warn "## Updating $file DS:$ds[1] minimum $ds2[4] -> $ds[4]\n";
	 	        RRDs::tune $file,"--minimum","$ds[1]:$ds[4]" unless $ds[4] eq $ds2[4];
	       }
	       if ($ds[5] ne $ds2[5]){
	       		warn "## Updating $file DS:$ds[1] maximum $ds2[5] -> $ds[5]\n";
	                RRDs::tune $file,"--maximum","$ds[1]:$ds[5]" unless $ds[5] eq $ds2[5];
	       }
	}
}	
		                        
1;