Graphing System Paging Activity With Perl And Sar

Note: Click the above picture to see it at 800x600.

Hey There,

For today's post, we're following in the footsteps of yesterday's activity, but moving on to scripting out system paging activity on a server. This script goes in a little bit of a different direction than the previous two, as we'll be charting out these values with bars. There are only so many wavy lines a guy can take ;)

This script was written on a Solaris box, and the output from "sar -g" on RedHat is distributed slightly differently (so the array elements I use to plot the Graph values in this script wouldn't give you precise results if you just ran this on Linux. They might be interesting, though ;). The script below is, again, written in Perl and will, run on Solaris Unix and RedHat Linux (Linux, again, with slight modification - but we'll definitely hit on that in a follow-up post when we've covered all 4 major bases).

This script is written to be run on the host it's measuring, since it runs sar at the time you invoke it, like so:

./sarpagegraph.pl

This Graph didn't turn out to look very visually striking, but the use of bars to represent triplicate y values seemed appropriate. Charts like these cause eyestrain, and resulting headaches, commensurate with the amount of sampled data crammed into the picture ;)

Again, click on the picture above to see it at its actual resolution :)

Cheers,





This work is licensed under a
Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License

#!/usr/bin/perl

#
# Sarpagegraph.pl
#
# Graph Paging Activity In Almost Real Time
#
# 2008 - Mike Golvach - eggi@comcast.net
#
# <a rel="license" href="http://creativecommons.org/licenses/by-nc-sa/3.0/us/">Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License</a>
#

use GIFgraph::bars;
open(SARG, "/usr/sbin/sar -g|");
@sarg = <SARG>;
close(SARG);
$my_graph = new GIFgraph::bars(800,600);
$my_graph->set( 
 x_label => 'Time',
 y1_label => 'Number',
 y2_label => 'Number',
 title => 'Paging Activity by Server - host',
 two_axes => 1,
 y_min_value => 0,
 y1_max_value => 20,
 y2_max_value => 20,
 y_tick_number => 5,
 long_ticks => 1,
 x_ticks => 0,
 legend_marker_width => 24,
 line_width => 10,
 bar_spacing => 0,
 gifx => 800,
 gify => 600,
 transparent => 1,
 dclrs => [ qw( red green blue black) ],
);
$my_graph->set_legend( qw( Pages_Paged_Out Pages_Added_To_Free_List Pages_Scanned ) );
$a = $b = $c = $d = 0;
foreach $line (@sarg) {
 next if ( ($line !~ /:/) || ($line =~ /\//));
 @line=split(" ", $line);
 if ( ( $a % 12 ) != 0 ) {
  $pandata0[$a] = undef;
 } else {
  $line[0] =~ s/:00$//;
  $pandata0[$a] = $line[0];
 }
 if ( $line[2] == 0 ) {
  $pandata1[$b] = 0;
 } else {
  $pandata1[$b] = $line[2];
 }
 if ( $line[2] == 0 ) {
  $pandata2[$c] = 0;
 } else {
  $pandata2[$c] = $line[3];
 }
 if ( $line[2] == 0 ) {
  $pandata3[$d] = 0;
 } else {
  $pandata3[$d] = $line[4];
 }
 $a++;
 $b++;
 $c++;
 $d++;
}
if ( ! $c ) {
 @pandata0[0] = `date "+%H:%M"`;
 @pandata1[0] = 0;
 @pandata2[0] = 0;
 @pandata3[0] = 0;
}
@data = (\@pandata0, \@pandata1, \@pandata2, \@pandata3);
$my_graph->plot_to_gif( "/your/data/storage/dir/sarg.gif", \@data );

, Mike

linux unix internet technology