NAME

       RRD::Simple::Examples - Examples using RRD::Simple

EXAMPLES

   Example 1: Basic Data Gathering Using vmstat
        use strict;
        use RRD::Simple;

        my $cmd = "/usr/bin/vmstat 2 3";
        my $rrdfile = "vmstat-cpu.rrd";
        my $rrd = RRD::Simple->new( file => $rrdfile );

        my @keys = ();
        my %update = ();
        open(PH,"-|",$cmd) or die qq{Unable to open file handle PH for command "$cmd": $!};
        while (local $_ = <PH>) {
            next if /---/;
            s/^\s+|\s+$//g;
            if (/\d+/ && @keys) {
                @update{@keys} = split(/\s+/,$_);
            } else { @keys = split(/\s+/,$_); }
        }
        close(PH) or die qq{Unable to close file handle PH for command "$cmd": $!};

        my @cpukeys = splice(@keys,-4,4);
        my %labels = (wa => "IO wait", id => "Idle", sy => "System", us => "User");

        $rrd->create(map { ($_ => "GAUGE") } @cpukeys) unless -f $rrdfile;
        $rrd->update(map { ($_ => $update{$_}) } @cpukeys);

   Example 2: Setting Minimum and Maximum Value Limits
       This example shows how to set the minimum value to zero on a datasource using the RRDs::tune function.
       Use "-i" or "--minimum" to set the minimum value, and "-a" or "--maximum" to set the maximum value.

       See <http://www.rrdtool.org/rrdtool/doc/rrdtune.en.html>.

        use strict;
        use RRD::Simple;
        use RRDs;

        my %update = ();
        my $cmd = "/usr/bin/iostat -k";

        open(PH,"-|",$cmd) or die qq{Unable to open file handle PH for command "$cmd": $!};
        while (local $_ = <PH>) {
            if (my ($dev,$r,$w) = $_ =~ /^([\w\d]+)\s+\S+\s+\S+\s+\S+\s+(\d+)\s+(\d+)$/) {
                $update{$dev} = { "read" => $r, "write" => $w };
            }
        }
        close(PH) or die qq{Unable to close file handle PH for command "$cmd": $!};

        for my $dev (keys %update) {
            my $rrdfile = "iostat-$dev.rrd";
            my $rrd = RRD::Simple->new( file => $rrdfile );

            unless (-f $rrdfile) {
                $rrd->create(
                        map { ($_ => "DERIVE") } sort keys %{$update{$dev}}
                    );
                RRDs::tune($rrdfile, "-i", "$_:0") for keys %{$update{$dev}};
            }

            $rrd->update(%{$update{$dev}});
        }

   Example 3: Creating RRDs with Different Data Retention Periods
       The second (optional) parameter to the create method is the data retention period. Valid values are
       "day", "week", "month", "year", "3years" and "mrtg".  The default value is "mrtg".

       The "mrtg" data retention period uses a data stepping resolution of 300 seconds (5 minutes) and heartbeat
       of 600 seconds (10 minutes), whereas all the other data retention periods use a data stepping resolution
       of 60 seconds (1 minute) and heartbeat of 120 seconds (2 minutes).

        use strict;
        use RRD::Simple;

        my $rrd = RRD::Simple->new( file => "myfile.rrd" );
        my @period = qw(day week month year 3years mrtg);
        $rrd->create($period[1],
                datasource1 => "GAUGE",
                datasource2 => "GAUGE",
                datasource3 => "GAUGE",
            );

   Example 4: Drawing an Average Value Horizonal Rule on a Graph
       Graph parameters are preserved and should be passed through to RRDs correctly: VDEF, CDEF, DEF, GPRINT,
       PRINT, COMMENT, HRULE, VRULE, LINE, AREA, TICK, SHIFT and STACK. Use the VDEF and HRULE parameters to
       draw a horizontal rule on your graph.

        use strict;
        use RRD::Simple;

        my $rrd = RRD::Simple->new( file => "frequency.rrd" );
        $rrd->create("day",
                Frequency => "GAUGE",
            );

        my $end = time();
        my $start = $end - (60 * 60 * 24);
        my $i = 0;
        my $rand = int(rand(100));

        for (my $t = $start; $t <= $end; $t += 60) {
            $rrd->update($t,
                    Frequency => ( cos($i += 0.01) * 100 ) + $rand,
                );
        }

        $rrd->graph(
                sources => [ qw(Frequency) ],
                "VDEF:FrequencyAVERAGE=Frequency,AVERAGE" => "",
                "HRULE:FrequencyAVERAGE#00ff77:Average" => "",
            );

   Example 5: Drawing a Fixed Height Stacked Graph
        use strict;
        use RRD::Simple;

        my $rrdfile = "vmstat-cpu.rrd";
        my $rrd = RRD::Simple->new( file => $rrdfile );

        $rrd->graph(
                title => "CPU Utilisation",
                vertical_label => "% percent",
                upper_limit => 100,
                lower_limit => 0,
                rigid => "",
                sources => [ qw(sy us wa id) ],
                source_drawtypes => [ qw(AREA STACK STACK STACK) ],
                extended_legend => 1,
            );

   Example 6: Setting Custom Graph Colours
       The "color" parameter can be used to override the default colours for standard elements of the graph.
       Valid elements are: BACK, CANVAS, SHADEA, SHADEB, GRID, MGRID, FONT, AXIS, FRAME and ARROW. See
       <http://oss.oetiker.ch/rrdtool/doc/rrdgraph.en.html> for further information.

        use strict;
        use RRD::Simple;

        my $rrd = RRD::Simple->new( file => "vmstat-cpu.rrd" );

        $rrd->graph(
                title => "CPU Utilisation",
                source_colors => {
                        sy => "ff0000",
                        us => "00ff00",
                        wa => "0000ff",
                        id => "ffffff",
                    },
                color => [ ( "BACK#F5F5FF", "SHADEA#C8C8FF",
                             "SHADEB#9696BE", "ARROW#61B51B",
                             "GRID#404852", "MGRID#67C6DE" ) ],
            );

   Example 7: Capacity Planning Predictions
        use strict;
        use RRD::Simple 1.44;

        my $rrd = RRD::Simple->new( file => "memory_usage.rrd" );

        $rrd->graph(
                periods => [ qw(week month) ],
                title => "Memory Utilisation",
                base => 1024,
                vertical_label => "bytes",
                sources => [ qw(Total Used) ],
                source_drawtypes => [ qw(AREA LINE) ],
                source_colors => [ qw(dddddd 0000dd) ],
                lower_limit => 0,
                rigid => "",
                "VDEF:D=Used,LSLSLOPE" => "",
                "VDEF:H=Used,LSLINT" => "",
                "VDEF:F=Used,LSLCORREL" => "",
                "CDEF:Proj=Used,POP,D,COUNT,*,H,+" => "",
                "LINE2:Proj#800000: Projection" => "",
            );

COPYRIGHT

       Copyright 2005,2006,2007,2008 Nicola Worthington.

       This software is licensed under The Apache Software License, Version 2.0.

       <http://www.apache.org/licenses/LICENSE-2.0>