Re: new plugin: check_system_load
On Sat, 8 Mar 2008, Steve Kemp wrote: Having said that though executing uptime on each incoming connection might increase resource usage at a time when the system is already loaded - but I'm certain that doing that will be a lot less resource intensive than running clamav, spambayes, and all the other tests that are typically conducted... Indeed. However, why do it at all when you don't need to? Cheers. -- Mark Powell - UNIX System Administrator - The University of Salford Information Services Division, Clifford Whitworth Building, Salford University, Manchester, M5 4WT, UK. Tel: +44 161 295 6843 Fax: +44 161 295 5888 www.pgp.com for PGP key
Re: new plugin: check_system_load
On Sat, 8 Mar 2008 16:08:10 +0100
Juerd Waalboer [EMAIL PROTECTED] wrote:
Peter Eisch skribis 2008-03-07 16:17 (-0600):
$self-{_args}-{uptime} = '/usr/bin/uptime'
if (! defined $self-{_args}-{uptime});
(...)
my $res = `$self-{_args}-{uptime}`;
Especially during high load, forking and executing uptime may not be
such a wise thing to do, depending on how well your platform handles
this under high load.
True. The goal is to avoid swamping the system.
I'm happy to take patches that keep the plugin universal and gather the
stats better.
Re: new plugin: check_system_load
On Sat Mar 08, 2008 at 10:02:12 -0600, Peter Eisch wrote:
I'm happy to take patches that keep the plugin universal and gather the
stats better.
How about something like this:
sub getLoad
{
#
# Use the module if we can.
#
my $test = use Sys::CpuLoad;;
eval( $test );
if ( $@ )
{
#
# Fall back to running process.
#
my $res = `uptime`;
if ($res =~ /aver\S+: (\d+\.\d+)/)
{
return( int( $1 ) );
}
}
else
{
my @loads = Sys::CpuLoad::load();
return( int($loads[0]) );
}
# fail?
return undef;
}
Steve
--
Re: new plugin: check_system_load
I started cleaning this up to use a block, not string eval, and pull the
check out of getload so it needn't be called as often... But really, if
your load is too high, do you want to be exec'ing uptime on every
call? I sure wouldn't. I say just require Sys::CpuLoad, warn and return
DECLINED if it's unavailable.
eval { require Sys::CpuLoad };
my $_has_sys_cpuload = !$@;
sub getLoad {
unless($_has_sys_cpuload) {
$self-log(LOGWARN, you must install Sys::CpuLoad to use this
module!);
return -1; #or undef or whatever
}
return int((Sys::CpuLoad::load())[0]);
}
Steve Kemp wrote:
On Sat Mar 08, 2008 at 10:02:12 -0600, Peter Eisch wrote:
I'm happy to take patches that keep the plugin universal and gather the
stats better.
How about something like this:
sub getLoad
{
#
# Use the module if we can.
#
my $test = use Sys::CpuLoad;;
eval( $test );
if ( $@ )
{
#
# Fall back to running process.
#
my $res = `uptime`;
if ($res =~ /aver\S+: (\d+\.\d+)/)
{
return( int( $1 ) );
}
}
else
{
my @loads = Sys::CpuLoad::load();
return( int($loads[0]) );
}
# fail?
return undef;
}
Steve
--
Brian Szymanski
email: [EMAIL PROTECTED]
skype: xbrianskix
cell: +1 202 747 4019
jabber: [EMAIL PROTECTED]
aim:xbrianskix
msn:[EMAIL PROTECTED]
Re: new plugin: check_system_load
On Sat Mar 08, 2008 at 15:21:48 -0500, Brian Szymanski wrote: I started cleaning this up to use a block, not string eval, and pull the check out of getload so it needn't be called as often... But really, if your load is too high, do you want to be exec'ing uptime on every call? I sure wouldn't. I say just require Sys::CpuLoad, warn and return DECLINED if it's unavailable. Good idea. Personally I'm always using the Sys::Cpuload module now, so I'll bow out of further discussion. (will update the code on my site/page to reflect the current module shortly.) Having said that though executing uptime on each incoming connection might increase resource usage at a time when the system is already loaded - but I'm certain that doing that will be a lot less resource intensive than running clamav, spambayes, and all the other tests that are typically conducted... Steve --
Re: new plugin: check_system_load
On 8-Mar-08, at 3:21 PM, Brian Szymanski wrote:
eval { require Sys::CpuLoad };
my $_has_sys_cpuload = !$@;
You might find this meme useful:
use constant HAVE_CPULOAD = eval { require Sys::CpuLoad };
Re: new plugin: check_system_load
On 3/7/08 3:39 PM, Steve Kemp [EMAIL PROTECTED] wrote:
This seems like rather an obvious idea: Reject new
connections if the system load is too high. But surprisingly
there seem to be no plugins which I could find implementing it.
I had posted this one to the list back a couple years ago. It works on
linux, bsd'en and solaris. Maybe on hpux too.
peter
#!/usr/bin/perl
=head1 NAME
loadcheck
=head1 DESCRIPTION
Only takes email transactions if the system load is at or below a
specified level.
=head1 CONFIG
max_load
This is the 1 minute system load where we won't take transactions
if our load is higher than this value. (Default: 7)
uptime
The path to the command 'uptime' if different than the default.
(Default: /usr/bin/uptime)
Example:
loadcheck max_load 7 uptime /usr/bin/uptime
=over 4
=head1 AUTHOR
Written by Peter Eisch [EMAIL PROTECTED].
=cut
my $VERSION = 0.01;
sub register {
my ($self, $qp, @args) = @_;
%{$self-{_args}} = @args;
$self-{_args}-{max_load} = 7
if (! defined $self-{_args}-{max_load});
$self-{_args}-{uptime} = '/usr/bin/uptime'
if (! defined $self-{_args}-{uptime});
$self-register_hook(connect, loadcheck);
}
sub loadcheck {
my ($self, $transaction) = @_;
my $hiload = 0;
my $cmd = $self-{_args}-{uptime};
#10:33AM up 2:06, 1 user, load averages: 6.55, 3.76, 2.48
# 12:29am 2 users, load average: 0.05, 0.05, 0.06
# 12:30am up 5 days, 12:43, 1 user, load average: 0.00, 0.00, 0.00
my $res = `$self-{_args}-{uptime}`;
if ($res =~ /aver\S+: (\d+\.\d+)/) {
$hiload = $1;
}
if ($hiload $self-{_args}-{max_load}) {
$self-log(LOGERROR, local load too high: $hiload);
return DENYSOFT;
}
return (DECLINED, continuing with load: $hiload);
}
Re: new plugin: check_system_load
Note - you'd be better off using Linux::SysInfo (on Linux, obviously) to save the backtick call. On 7-Mar-08, at 4:39 PM, Steve Kemp wrote: This seems like rather an obvious idea: Reject new connections if the system load is too high. But surprisingly there seem to be no plugins which I could find implementing it. So here's mine: http://mail-scanning.com/qpsmtpd/system-load This reads /etc/qpsmtpd/max_system_load, and if the system load is equal or higher than the value contained within it it is rejected. Comments welcome, and I'm happy for it to be used in the core, or in contrib if there is any interest. Steve -- http://mail-scanning.com/
Re: new plugin: check_system_load
On Fri Mar 07, 2008 at 17:48:22 -0500, Matt Sergeant wrote: Note - you'd be better off using Linux::SysInfo (on Linux, obviously) to save the backtick call. Noted. I'll update the code to use that where possible. (Right now I figured portability would be a good thing - although I realise my regexp fails there!) Steve --
