126 lines
3.2 KiB
Perl
Executable File
126 lines
3.2 KiB
Perl
Executable File
#!/usr/bin/perl
|
|
|
|
=head1 NAME
|
|
|
|
loadcheck
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
Only takes email transactions if the system load is at or below a
|
|
specified level.
|
|
|
|
If this is running on a system that provides /kern/loadavg or
|
|
/proc/loadavg it will be used instead of the 'uptime' command.
|
|
|
|
Once a load value is determined, it is cached for a period of time.
|
|
See the cache_time below.
|
|
|
|
Since fork/exec is expensive in perl you'll want to use cache_time to avoid increasing your load on every connection by checking system load.
|
|
|
|
=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)
|
|
|
|
cache_time
|
|
|
|
A recently determined load value will be cached and used for the
|
|
assigned number of seconds. (Default: 10)
|
|
|
|
uptime
|
|
|
|
The path to the command 'uptime' if different than the default.
|
|
(Default: /usr/bin/uptime)
|
|
|
|
Example:
|
|
|
|
loadcheck cache_time 30
|
|
|
|
loadcheck max_load 7 uptime /usr/bin/uptime
|
|
|
|
=head1 SEE ALSO
|
|
|
|
Original version: http://www.nntp.perl.org/group/perl.qpsmtpd/2006/01/msg4422.html
|
|
|
|
Variant with caching: http://www.nntp.perl.org/group/perl.qpsmtpd/2006/03/msg4710.html
|
|
|
|
Steve Kemp's announcement of an alternate load limiter: http://www.nntp.perl.org/group/perl.qpsmtpd/2008/03/msg7814.html
|
|
|
|
=head1 AUTHOR
|
|
|
|
Written by Peter Eisch <peter@boku.net>.
|
|
|
|
=cut
|
|
|
|
my $VERSION = 0.02;
|
|
|
|
sub register {
|
|
my ($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->{_args}->{cache_time} = 10
|
|
if (! defined $self->{_args}->{cache_time});
|
|
|
|
$self->{_load} = -1;
|
|
$self->{_time} = 0;
|
|
|
|
$self->register_hook("connect", "loadcheck");
|
|
}
|
|
|
|
sub loadcheck {
|
|
my ($self, $transaction) = @_;
|
|
|
|
if (time() > ($self->{_time} + $self->{_args}->{cache_time})) {
|
|
# cached value expired
|
|
|
|
if ( -r '/kern/loadavg' ) { # *BSD
|
|
# contains fix-point scaling value
|
|
open(LD, "</kern/loadavg");
|
|
my $res = <LD>;
|
|
close LD;
|
|
my @vals = split(/ /, $res);
|
|
$self->{_load} = ($val[0] / $val[3]);
|
|
$self->{_time} = time();
|
|
$self->log(LOGDEBUG, "/kern/loadavg reported: $self->{_load}");
|
|
} elsif ( -r '/proc/loadavg' ) { # *inux
|
|
# contains decimal value
|
|
# contains fix-point scaling value
|
|
open(LD, "</proc/loadavg");
|
|
my $res = <LD>;
|
|
close LD;
|
|
$self->{_load} = (split(/ /, $res))[0];
|
|
$self->{_time} = time();
|
|
$self->log(LOGDEBUG, "/proc/loadavg reported: $self->{_load}");
|
|
} else {
|
|
# the various formats returned:
|
|
#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+)/) {
|
|
$self->{_load} = $1;
|
|
$self->{_time} = time();
|
|
$self->log(LOGDEBUG, "$self->{_args}->{uptime} reported: $self->{_load}");
|
|
}
|
|
}
|
|
}
|
|
|
|
if ($self->{_load} > $self->{_args}->{max_load}) {
|
|
$self->log(LOGERROR, "local load too high: $self->{_load}");
|
|
return DENYSOFT;
|
|
}
|
|
|
|
return (DECLINED, "continuing with load: $self->{_load}");
|
|
}
|
|
|