initial commit

README

+Revision of check_mem.pl that splits out cache memory from application memory - see http://sysadminsjourney.com/content/2009/06/04/new-and-improved-checkmempl-nagios-plugin

check_mem.pl

+#!/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;
+}