#!/usr/bin/perl -w

#
# syswatcher.pl
#
# Developed by Lubomir Host 'rajo' <rajo AT platon.sk>
# Copyright (c) 2003 Platon SDG, http://platon.sk/
# Licensed under terms of GNU General Public License.
# All rights reserved.
#
# Changelog:
# 15/10/2003 - created
# 16/10/2003 - added automatic database reconnecting (nepto)
#

# $Platon: scripts/perl/syswatcher/syswatcher.pl,v 1.7 2004/01/05 11:34:21 nepto Exp $

use strict;

use DBI;
use Time::HiRes qw(gettimeofday sleep usleep);
use POSIX qw(strftime);

# declaration: {{{
use vars qw (
	$database
	$dbh
	$sql_loadavg
	$sql_meminfo

	$update_interval
);

# functions
sub PrepareSQL();
sub print_info($;);
sub loadavg();
sub meminfo();

# }}}

$database	= "DBI:mysql:database=system;host=localhost;user=syswatcher;password=;compression=0";

# time between 2 inserts or reconnects:
# range of this value: (2, 1E6)
$update_interval	= 10; # seconds

#
# MAIN
#

FORK: {
	my $pid;
	if ($pid = fork) {
		# parent
		exit 0;
	}
	elsif (defined $pid) {
		# child
	}
	elsif ($! =~ /No more process/) {
		# EAGAIN
		warn "Can't fork: $!";
		sleep 5;
		redo fork;
	}
	else {
		die "Can't fork: $!";
	}
}

print_info("PID = $$ $0 started");

while (1) {

	while (! ($dbh = DBI->connect($database))) {
		print_info("Database connection failed, reconnecting in $update_interval seconds...($DBI::errstr)");
		sleep $update_interval;
	}

	PrepareSQL();

	Time::HiRes::sleep ($update_interval - (Time::HiRes::gettimeofday % $update_interval));
	while ($dbh) {

		my $sleep = 1;
		while (!defined($dbh) or ref($dbh) ne 'DBI::db' or !($dbh->ping())) {
			print STDERR "CheckDB - db ping error\n";
			sleep $sleep;
			$sleep += 10 if ($sleep < 120);
		}  

		$dbh->{mysql_auto_reconnect} = 1;

		#  
		# DB ping must be done twice (bug in DBI??), otherwise warning "DBD::mysql::st execute warning:" [rajo]
		#  
		my $rv = $dbh->ping();
		$dbh->{mysql_auto_reconnect} = 1;

		last if (! loadavg());
		last if (! meminfo());

		Time::HiRes::sleep ($update_interval - (Time::HiRes::gettimeofday % $update_interval));

		my $modify_time = -86400.0 * -M $0;
		if (defined $modify_time && $modify_time > 0) { # Autorestart - if file exists and is modified
			print_info("Script '$0' MODIFIED $modify_time seconds after startup, restarting ...");
			exec $0, @ARGV;
		} 
	}

	sleep $update_interval;
}

sub PrepareSQL()
{ # {{{
	
	$sql_loadavg = $dbh->prepare("
		INSERT INTO loadavg
			(load1, load5, load15, procs_run, procs_total, last_pid)
			VALUES (?, ?, ?, ?, ?, ?)
		");

	# parameters HugePages_Total, HugePages_Free, Hugepagesize depeds on kernel config
	# (not always available in /proc/meminfo)
	$sql_meminfo= $dbh->prepare("
		INSERT INTO meminfo
			(MemTotal,	MemFree,	Buffers,		Cached,		SwapCached,
			Active,		Inactive,	HighTotal,		HighFree,	LowTotal,
			LowFree,	SwapTotal,	SwapFree,		Dirty,		Writeback,
			Mapped,		Slab,		Committed_AS,	PageTables,	VmallocTotal,
			VmallocUsed,	VmallocChunk,	HugePages_Total,	HugePages_Free,	Hugepagesize)
			VALUES ( ?, ?, ?, ?, ?, ?, ?, ?, ?, ?,
			?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
		"); # 25 values

} # }}}

sub cur_date()
{ # {{{
	my ($sec, $msec) = Time::HiRes::gettimeofday;
	$msec = sprintf("%06g", $msec);
	my $time_string = strftime "%Y/%m/%d %X.$msec", gmtime;

	return $time_string;
} # }}}

sub print_info($;)
{ # {{{
	my ($text) = @_;

	printf STDERR "[%s] %s\n", cur_date(), $text;

} # }}}
			
sub loadavg()
{ # {{{

	open FILE, "</proc/loadavg" or die "loadavg(): $!";
	my ($load1, $load5, $load15, $procs_run, $procs_total, $last_pid) = split /[ \/]+/, <FILE>;
	
	$sql_loadavg->execute(
		$load1, $load5, $load15, $procs_run, $procs_total, $last_pid) or warn $dbh->errstr;
	#print_info("Loadavg inserted");
	
	close FILE;

	return 1;

} # }}}

sub meminfo()
{ # {{{
	my %xx;

	open FILE, "</proc/meminfo" or die "loadavg(): $!";

	while (my $line = <FILE>) {
		if ($line =~ m/^([a-z_]+)[ :]*([0-9]+).*$/i) {
			$xx{$1} = $2;
		}
	}
	close FILE;

	$sql_meminfo->execute(
		$xx{MemTotal},		$xx{MemFree},	$xx{Buffers},		$xx{Cached},	$xx{SwapCached},
		$xx{Active},		$xx{Inactive},	$xx{HighTotal},		$xx{HighFree},	$xx{LowTotal},
		$xx{LowFree},		$xx{SwapTotal},	$xx{SwapFree},		$xx{Dirty},		$xx{Writeback},
		$xx{Mapped},		$xx{Slab},		$xx{Committed_AS},	$xx{PageTables},$xx{VmallocTotal},
		$xx{VmallocUsed},	$xx{VmallocChunk}, $xx{HugePages_Total}, $xx{HugePages_Free}, $xx{Hugepagesize}
	) or warn $dbh->errstr;
	#print_info("Meminfo inserted");
	
	return 1;

} # }}}

# vim: ts=4
# vim600: fdm=marker fdl=0 fdc=3