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blog:plugin_to_check_free_server_memory_with_nagios [2011-08-08 19:43] – brbblog:plugin_to_check_free_server_memory_with_nagios [2011-08-08 19:43] – brb
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 <file perl> <file perl>
 +#!/usr/bin/perl -w
 +# $Id: check_mem.pl 2 2002-02-28 06:42:51Z egalstad $
 +
 +# Original script stolen from:
 +# check_mem.pl Copyright (C) 2000 Dan Larsson <dl@tyfon.net>
 +# hacked by
 +# Justin Ellison <justin@techadvise.com>
 +#
 +# 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 (or with Nagios);  if not, write to the
 +# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 +# Boston, MA 02111-1307, USA
 +
 +# Tell Perl what we need to use
 +use strict;
 +use Getopt::Std;
 +
 +#TODO - Convert to Nagios::Plugin
 +#TODO - Use an alarm
 +
 +# Predefined exit codes for Nagios
 +use vars qw($opt_c $opt_f $opt_u $opt_w $opt_C $opt_v %exit_codes);
 +%exit_codes   = ('UNKNOWN' ,-1,
 +        'OK'      , 0,
 +                 'WARNING' , 1,
 +                 'CRITICAL', 2,
 +                 );
 +
 +# Get our variables, do our checking:
 +init();
 +
 +# Get the numbers:
 +my ($free_memory_kb,$used_memory_kb,$caches_kb) = get_memory_info();
 +print "$free_memory_kb Free\n$used_memory_kb Used\n$caches_kb Cache\n" if ($opt_v);
 +
 +if ($opt_C) { #Do we count caches as free?
 +    $used_memory_kb -= $caches_kb;
 +    $free_memory_kb += $caches_kb;
 +}
 +
 +# Round to the nearest KB
 +$free_memory_kb = sprintf('%d',$free_memory_kb);
 +$used_memory_kb = sprintf('%d',$used_memory_kb);
 +$caches_kb = sprintf('%d',$caches_kb);
 +
 +# Tell Nagios what we came up with
 +tell_nagios($used_memory_kb,$free_memory_kb,$caches_kb);
 +
 +
 +sub tell_nagios {
 +    my ($used,$free,$caches) = @_;
 +    
 +    # Calculate Total Memory
 +    my $total = $free + $used;
 +    print "$total Total\n" if ($opt_v);
 +
 +    my $perfdata = "|TOTAL=${total}KB;;;; USED=${used}KB;;;; FREE=${free}KB;;;; CACHES=${caches}KB;;;;";
 +    
 +    if ($opt_f) {
 +      my $percent    = sprintf "%.1f", ($free / $total * 100);
 +      if ($percent <= $opt_c) {
 +          finish("CRITICAL - $percent% ($free kB) free!$perfdata",$exit_codes{'CRITICAL'});
 +      }
 +      elsif ($percent <= $opt_w) {
 +          finish("WARNING - $percent% ($free kB) free!$perfdata",$exit_codes{'WARNING'});
 +      }
 +      else {
 +          finish("OK - $percent% ($free kB) free.$perfdata",$exit_codes{'OK'});
 +      }
 +    }
 +    elsif ($opt_u) {
 +      my $percent    = sprintf "%.1f", ($used / $total * 100);
 +      if ($percent >= $opt_c) {
 +          finish("CRITICAL - $percent% ($used kB) used!|$perfdata",$exit_codes{'CRITICAL'});
 +      }
 +      elsif ($percent >= $opt_w) {
 +          finish("WARNING - $percent% ($used kB) used!|$perfdata",$exit_codes{'WARNING'});
 +      }
 +      else {
 +          finish("OK - $percent% ($used kB) used.|$perfdata",$exit_codes{'OK'});
 +      }
 +    }
 +}
 +
 +# Show usage
 +sub usage() {
 +  print "\ncheck_mem.pl v1.0 - Nagios Plugin\n\n";
 +  print "usage:\n";
 +  print " check_mem.pl -<f|u> -w <warnlevel> -c <critlevel>\n\n";
 +  print "options:\n";
 +  print " -f           Check FREE memory\n";
 +  print " -u           Check USED memory\n";
 +  print " -C           Count OS caches as FREE memory\n";
 +  print " -w PERCENT   Percent free/used when to warn\n";
 +  print " -c PERCENT   Percent free/used when critical\n";
 +  print "\nCopyright (C) 2000 Dan Larsson <dl\@tyfon.net>\n";
 +  print "check_mem.pl comes with absolutely NO WARRANTY either implied or explicit\n";
 +  print "This program is licensed under the terms of the\n";
 +  print "GNU General Public License (check source code for details)\n";
 +  exit $exit_codes{'UNKNOWN'}; 
 +}
 +
 +sub get_memory_info {
 +    my $used_memory_kb  = 0;
 +    my $free_memory_kb  = 0;
 +    my $total_memory_kb = 0;
 +    my $caches_kb       = 0;
 +
 +    my $uname;
 +    if ( -e '/usr/bin/uname') {
 +        $uname = `/usr/bin/uname -a`;
 +    }
 +    elsif ( -e '/bin/uname') {
 +        $uname = `/bin/uname -a`;
 +    }
 +    else {
 +        die "Unable to find uname in /usr/bin or /bin!\n";
 +    }
 +    print "uname returns $uname" if ($opt_v);
 +    if ( $uname =~ /Linux/ ) {
 +        my @meminfo = `/bin/cat /proc/meminfo`;
 +        foreach (@meminfo) {
 +            chomp;
 +            if (/^Mem(Total|Free):\s+(\d+) kB/) {
 +                my $counter_name = $1;
 +                if ($counter_name eq 'Free') {
 +                    $free_memory_kb = $2;
 +                }
 +                elsif ($counter_name eq 'Total') {
 +                    $total_memory_kb = $2;
 +                }
 +            }
 +            elsif (/^(Buffers|Cached):\s+(\d+) kB/) {
 +                $caches_kb += $2;
 +            }
 +        }
 +        $used_memory_kb = $total_memory_kb - $free_memory_kb;
 +    }
 +    elsif ( $uname =~ /SunOS/ ) {
 +        eval "use Sun::Solaris::Kstat";
 +        if ($@) { #Kstat not available
 +            if ($opt_C) {
 +                print "You can't report on Solaris caches without Sun::Solaris::Kstat available!\n";
 +                exit $exit_codes{UNKNOWN};
 +            }
 +            my @vmstat = `/usr/bin/vmstat 1 2`;
 +            my $line;
 +            foreach (@vmstat) {
 +              chomp;
 +              $line = $_;
 +            }
 +            $free_memory_kb = (split(/ /,$line))[5] / 1024;
 +            my @prtconf = `/usr/sbin/prtconf`;
 +            foreach (@prtconf) {
 +                if (/^Memory size: (\d+) Megabytes/) {
 +                    $total_memory_kb = $1 * 1024;
 +                }
 +            }
 +            $used_memory_kb = $total_memory_kb - $free_memory_kb;
 +            
 +        }
 +        else { # We have kstat
 +            my $kstat = Sun::Solaris::Kstat->new();
 +            my $phys_pages = ${kstat}->{unix}->{0}->{system_pages}->{physmem};
 +            my $free_pages = ${kstat}->{unix}->{0}->{system_pages}->{freemem};
 +            # We probably should account for UFS caching here, but it's unclear
 +            # to me how to determine UFS's cache size.  There's inode_cache,
 +            # and maybe the physmem variable in the system_pages module??
 +            # In the real world, it looks to be so small as not to really matter,
 +            # so we don't grab it.  If someone can give me code that does this, 
 +            # I'd be glad to put it in.
 +            my $arc_size = (exists ${kstat}->{zfs} && ${kstat}->{zfs}->{0}->{arcstats}->{size}) ?
 +                 ${kstat}->{zfs}->{0}->{arcstats}->{size} / 1024 
 +                 : 0;
 +            $caches_kb += $arc_size;
 +            my $pagesize = `pagesize`;
 +    
 +            $total_memory_kb = $phys_pages * $pagesize / 1024;
 +            $free_memory_kb = $free_pages * $pagesize / 1024;
 +            $used_memory_kb = $total_memory_kb - $free_memory_kb;
 +        }
 +    }
 +    else {
 +        if ($opt_C) {
 +            print "You can't report on $uname caches!\n";
 +            exit $exit_codes{UNKNOWN};
 +        }
 +    my $command_line = `vmstat | tail -1 | awk '{print \$4,\$5}'`;
 +    chomp $command_line;
 +        my @memlist      = split(/ /, $command_line);
 +    
 +        # Define the calculating scalars
 +        $used_memory_kb  = $memlist[0]/1024;
 +        $free_memory_kb = $memlist[1]/1024;
 +        $total_memory_kb = $used_memory_kb + $free_memory_kb;
 +    }
 +    return ($free_memory_kb,$used_memory_kb,$caches_kb);
 +}
 +
 +sub init {
 +    # Get the options
 +    if ($#ARGV le 0) {
 +      &usage;
 +    }
 +    else {
 +      getopts('c:fuCvw:');
 +    }
 +    
 +    # Shortcircuit the switches
 +    if (!$opt_w or $opt_w == 0 or !$opt_c or $opt_c == 0) {
 +      print "*** You must define WARN and CRITICAL levels!\n";
 +      &usage;
 +    }
 +    elsif (!$opt_f and !$opt_u) {
 +      print "*** You must select to monitor either USED or FREE memory!\n";
 +      &usage;
 +    }
 +    
 +    # Check if levels are sane
 +    if ($opt_w <= $opt_c and $opt_f) {
 +      print "*** WARN level must not be less than CRITICAL when checking FREE memory!\n";
 +      &usage;
 +    }
 +    elsif ($opt_w >= $opt_c and $opt_u) {
 +      print "*** WARN level must not be greater than CRITICAL when checking USED memory!\n";
 +      &usage;
 +    }
 +}
 +
 +sub finish {
 +    my ($msg,$state) = @_;
 +    print "$msg\n";
 +    exit $state;
 +}
 +</file>
  
 Ref: http://www.sysadminsjourney.com/content/2009/06/04/new-and-improved-checkmempl-nagios-plugin?nocache=1 Ref: http://www.sysadminsjourney.com/content/2009/06/04/new-and-improved-checkmempl-nagios-plugin?nocache=1
blog/plugin_to_check_free_server_memory_with_nagios.txt · Last modified: 2011-08-08 19:47 by brb