Sys::Statistics::Linux(3pm)				User Contributed Perl Documentation			       Sys::Statistics::Linux(3pm)

NAME

       Sys::Statistics::Linux - Front-end module to collect system statistics

SYNOPSIS

	   use Sys::Statistics::Linux;

	   my $lxs = Sys::Statistics::Linux->new(
	       sysinfo	 => 1,
	       cpustats  => 1,
	       procstats => 1,
	       memstats  => 1,
	       pgswstats => 1,
	       netstats  => 1,
	       sockstats => 1,
	       diskstats => 1,
	       diskusage => 1,
	       loadavg	 => 1,
	       filestats => 1,
	       processes => 1,
	   );

	   sleep 1;
	   my $stat = $lxs->get;

DESCRIPTION

       Sys::Statistics::Linux is a front-end module and gather different linux system information like processor workload, memory usage, network
       and disk statistics and a lot more. Refer the documentation of the distribution modules to get more information about all possible
       statistics.

MOTIVATION

       My motivation is very simple... every linux administrator knows the well-known tool sar of sysstat.  It helps me a lot of time to search
       for system bottlenecks and to solve problems, but it's hard to parse the output if you want to store the statistics into a database. So I
       thought to develope Sys::Statistics::Linux. It's not a replacement but it should make it simpler to you to write your own system monitor.

       If Sys::Statistics::Linux doesn't provide statistics that are strongly needed then let me know it.

TECHNICAL NOTE

       This distribution collects statistics by the virtual /proc filesystem (procfs) and is developed on the default vanilla kernel. It is tested
       on x86 hardware with the distributions RHEL, Fedora, Debian, Ubuntu, Asianux, Slackware, Mandriva and openSuSE (SLES on zSeries as well but
       a long time ago) on kernel versions 2.4 and/or 2.6. It's possible that it doesn't run on all linux distributions if some procfs features
       are deactivated or too much modified.  As example the linux kernel 2.4 can compiled with the option "CONFIG_BLK_STATS" what turn on or off
       block statistics for devices.

       Don't give up if some of the modules doesn't run on your hardware! Tell me what's wrong and I will try to solve it! You just have to make
       the first move and to send me a mail. :-)

VIRTUAL MACHINES

       Note that if you try to install or run "Sys::Statistics::Linux" under virtual machines on guest systems that some statistics are not
       available, such as "SockStats", "PgSwStats" and "DiskStats". The reason is that not all /proc data are passed to the guests.

       If the installation fails then try to force the installation with

	   cpan> force install Sys::Statistics::Linux

       and notice which tests fails, because this statistics maybe not available on the virtual machine - sorry.

DELTAS

       The statistics for "CpuStats", "ProcStats", "PgSwStats", "NetStats", "DiskStats" and "Processes" are deltas, for this reason it's necessary
       to initialize the statistics before the data can be prepared by "get()". These statistics can be initialized with the methods "new()",
       "set()" and "init()". For any option that is set to 1, the statistics will be initialized by the call of "new()" or "set()". The call of
       init() re-initialize all statistics that are set to 1 or 2.  By the call of "get()" the initial statistics will be updated automatically.
       Please refer the section "METHODS" to get more information about the usage of "new()", "set()", "init()" and "get()".

       Another exigence is to sleep for a while - at least for one second - before the call of "get()" if you want to get useful statistics. The
       statistics for "SysInfo", "MemStats", "SockStats", "DiskUsage", "LoadAVG" and "FileStats" are no deltas. If you need only one of these
       information you don't need to sleep before the call of "get()".

       The method "get()" prepares all requested statistics and returns the statistics as a Sys::Statistics::Linux::Compilation object. The inital
       statistics will be updated.

MANUAL 
PROC(5)
       The Linux Programmer's Manual

	   http://www.kernel.org/doc/man-pages/online/pages/man5/proc.5.html

       If you have questions or don't understand the sense of some statistics then take a look into this awesome documentation.

OPTIONS

       All options are identical with the package names of the distribution in lowercase. To activate the gathering of statistics you have to set
       the options by the call of "new()" or "set()".  In addition you can deactivate statistics with "set()".

       The options must be set with one of the following values:

	   0 - deactivate statistics
	   1 - activate and init statistics
	   2 - activate statistics but don't init

       In addition it's possible to pass a hash reference with options.

	   my $lxs = Sys::Statistics::Linux->new(
	       processes => {
		   init => 1,
		   pids => [ 1, 2, 3 ]
	       },
	       netstats => {
		   init => 1,
		   initfile => $file,
	       },
	   );

       Option "initfile" is useful if you want to store initial statistics on the filesystem.

	   my $lxs = Sys::Statistics::Linux->new(
	       cpustats => {
		   init     => 1,
		   initfile => '/tmp/cpustats.yml',
	       },
	       diskstats => {
		   init     => 1,
		   initfile => '/tmp/diskstats.yml',
	       },
	       netstats => {
		   init     => 1,
		   initfile => '/tmp/netstats.yml',
	       },
	       pgswstats => {
		   init     => 1,
		   initfile => '/tmp/pgswstats.yml',
	       },
	       procstats => {
		   init     => 1,
		   initfile => '/tmp/procstats.yml',
	       },
	   );

       Example:

	   #!/usr/bin/perl
	   use strict;
	   use warnings;
	   use Sys::Statistics::Linux;

	   my $lxs = Sys::Statistics::Linux->new(
	       pgswstats => {
		   init => 1,
		   initfile => '/tmp/pgswstats.yml'
	       }
	   );

	   $lxs->get(); # without to sleep

       The initial statistics are stored to the temporary file:

	   #> cat /tmp/pgswstats.yml
	   ---
	   pgfault: 397040955
	   pgmajfault: 4611
	   pgpgin: 21531693
	   pgpgout: 49511043
	   pswpin: 8
	   pswpout: 272
	   time: 1236783534.9328

       Every time you call the script the initial statistics are loaded/stored from/to the file.  This could be helpful if you doesn't run it as
       daemon and if you want to calculate the average load of your system since the last call. Do you understand? I hope so :)

       To get more information about the statistics refer the different modules of the distribution.

	   sysinfo     -  Collect system information		  with Sys::Statistics::Linux::SysInfo.
	   cpustats    -  Collect cpu statistics		  with Sys::Statistics::Linux::CpuStats.
	   procstats   -  Collect process statistics		  with Sys::Statistics::Linux::ProcStats.
	   memstats    -  Collect memory statistics		  with Sys::Statistics::Linux::MemStats.
	   pgswstats   -  Collect paging and swapping statistics  with Sys::Statistics::Linux::PgSwStats.
	   netstats    -  Collect net statistics		  with Sys::Statistics::Linux::NetStats.
	   sockstats   -  Collect socket statistics		  with Sys::Statistics::Linux::SockStats.
	   diskstats   -  Collect disk statistics		  with Sys::Statistics::Linux::DiskStats.
	   diskusage   -  Collect the disk usage		  with Sys::Statistics::Linux::DiskUsage.
	   loadavg     -  Collect the load average		  with Sys::Statistics::Linux::LoadAVG.
	   filestats   -  Collect inode statistics		  with Sys::Statistics::Linux::FileStats.
	   processes   -  Collect process statistics		  with Sys::Statistics::Linux::Processes.

METHODS

   new()
       Call "new()" to create a new Sys::Statistics::Linux object. You can call "new()" with options.  This options would be passed to the method
       "set()".

       Without options

	   my $lxs = Sys::Statistics::Linux->new();

       Or with options

	   my $lxs = Sys::Statistics::Linux->new( cpustats => 1 );

       Would do nothing

	   my $lxs = Sys::Statistics::Linux->new( cpustats => 0 );

       It's possible to call "new()" with a hash reference of options.

	   my %options = (
	       cpustats => 1,
	       memstats => 1
	   );

	   my $lxs = Sys::Statistics::Linux->new(\%options);

   set()
       Call "set()" to activate or deactivate options.

       The following example would call "new()" and initialize "Sys::Statistics::Linux::CpuStats" and delete the object of
       "Sys::Statistics::Linux::SysInfo".

	   $lxs->set(
	       processes =>  0, # deactivate this statistic
	       pgswstats =>  1, # activate the statistic and calls new() and init() if necessary
	       netstats  =>  2, # activate the statistic and call new() if necessary but not init()
	   );

       It's possible to call "set()" with a hash reference of options.

	   my %options = (
	       cpustats => 2,
	       memstats => 2
	   );

	   $lxs->set(\%options);

   get()
       Call "get()" to get the collected statistics. "get()" returns a Sys::Statistics::Linux::Compilation object.

	   my $lxs  = Sys::Statistics::Linux->new(\%options);
	   sleep(1);
	   my $stat = $lxs->get();

       Or you can pass the time to sleep with the call of "get()".

	   my $stat = $lxs->get($time_to_sleep);

       Now the statistcs are available with

	   $stat->cpustats

	   # or

	   $stat->{cpustats}

       Take a look to the documentation of Sys::Statistics::Linux::Compilation for more information.

   init()
       The call of "init()" initiate all activated statistics that are necessary for deltas. That could be helpful if your script runs in a
       endless loop with a high sleep interval. Don't forget that if you call "get()" that the statistics are deltas since the last time they were
       initiated.

       The following example would calculate average statistics for 30 minutes:

	   # initiate cpustats
	   my $lxs = Sys::Statistics::Linux->new( cpustats => 1 );

	   while ( 1 ) {
	       sleep(1800);
	       my $stat = $lxs->get;
	   }

       If you just want a current snapshot of the system each 30 minutes and not the average then the following example would be better for you:

	   # do not initiate cpustats
	   my $lxs = Sys::Statistics::Linux->new( cpustats => 2 );

	   while ( 1 ) {
	       $lxs->init;		# init the statistics
	       my $stat = $lxs->get(1); # get the statistics
	       sleep(1800);		# sleep until the next run
	   }

       If you want to write a simple command line utility that prints the current workload to the screen then you can use something like this:

	   my @order = qw(user system iowait idle nice irq softirq total);
	   printf "%-20s%8s%8s%8s%8s%8s%8s%8s%8s
", 'time', @order;

	   my $lxs = Sys::Statistics::Linux->new( cpustats => 1 );

	   while ( 1 ){
	       my $cpu	= $lxs->get(1)->cpustats;
	       my $time = $lxs->gettime;
	       printf "%-20s%8s%8s%8s%8s%8s%8s%8s%8s
",
		   $time, @{$cpu->{cpu}}{@order};
	   }

   settime()
       Call "settime()" to define a POSIX formatted time stamp, generated with localtime().

	   $lxs->settime('%Y/%m/%d %H:%M:%S');

       To get more information about the formats take a look at "strftime()" of POSIX.pm or the manpage strftime(3).

   gettime()
       "gettime()" returns a POSIX formatted time stamp, @foo in list and $bar in scalar context.  If the time format isn't set then the default
       format "%Y-%m-%d %H:%M:%S" will be set automatically. You can also set a time format with "gettime()".

	   my $date_time = $lxs->gettime;

       Or

	   my ($date, $time) = $lxs->gettime();

       Or

	   my ($date, $time) = $lxs->gettime('%Y/%m/%d %H:%M:%S');

EXAMPLES

       A very simple perl script could looks like this:

	   use strict;
	   use warnings;
	   use Sys::Statistics::Linux;

	   my $lxs = Sys::Statistics::Linux->new( cpustats => 1 );
	   sleep(1);
	   my $stat = $lxs->get;
	   my $cpu  = $stat->cpustats->{cpu};

	   print "Statistics for CpuStats (all)
";
	   print "  user      $cpu->{user}
";
	   print "  nice      $cpu->{nice}
";
	   print "  system    $cpu->{system}
";
	   print "  idle      $cpu->{idle}
";
	   print "  ioWait    $cpu->{iowait}
";
	   print "  total     $cpu->{total}
";

       Set and get a time stamp:

	   use strict;
	   use warnings;
	   use Sys::Statistics::Linux;

	   my $lxs = Sys::Statistics::Linux->new();
	   $lxs->settime('%Y/%m/%d %H:%M:%S');
	   print $lxs->gettime, "
";

       If you want to know how the data structure looks like you can use "Data::Dumper" to check it:

	   use strict;
	   use warnings;
	   use Sys::Statistics::Linux;
	   use Data::Dumper;

	   my $lxs = Sys::Statistics::Linux->new( cpustats => 1 );
	   sleep(1);
	   my $stat = $lxs->get;

	   print Dumper($stat);

       How to get the top 5 processes with the highest cpu workload:

	   use strict;
	   use warnings;
	   use Sys::Statistics::Linux;

	   my $lxs = Sys::Statistics::Linux->new( processes => 1 );
	   sleep(1);
	   my $stat = $lxs->get;
	   my @top5 = $stat->pstop( ttime => 5 );

BACKWARD COMPATIBILITY

       The old options and keys - CpuStats, NetStats, etc - are still available but deprecated!  It's not possible to access the statistics via
       Sys::Statistics::Linux::Compilation and it's not possible to call "search()" and "psfind()" if you use the old options.

       You should use the new options and access the statistics over the accessors

	   $stats->cpustats

       or directly with

	   $stats->{cpustats}

PREREQUISITES

	   Carp
	   POSIX
	   Test::More
	   Time::HiRes
	   UNIVERSAL

EXPORTS

       No exports.

TODOS

	  * Are there any wishs from your side? Send me a mail!

REPORTING BUGS

       Please report all bugs to <jschulz.cpan(at)bloonix.de>.

AUTHOR

       Jonny Schulz <jschulz.cpan(at)bloonix.de>.

COPYRIGHT

       Copyright (C) 2006-2008 by Jonny Schulz. All rights reserved.

       This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

perl v5.14.2							    2012-03-09					       Sys::Statistics::Linux(3pm)