Merge pull request #43 from msimerson/master

loadcheck: refactored. See =CHANGES section
This commit is contained in:
Matt Simerson 2014-03-21 21:07:37 -07:00
commit d60882c857

141
plugins/loadcheck Executable file → Normal file
View File

@ -7,15 +7,16 @@ loadcheck
=head1 DESCRIPTION
Only takes email transactions if the system load is at or below a
specified level.
specified level.
If this is running on a system that provides /kern/loadavg or
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.
Since fork/exec is expensive in perl, if using the 'uptime' method,
use cache_time to avoid increasing your load on every connection.
=head1 CONFIG
@ -31,7 +32,7 @@ assigned number of seconds. (Default: 10)
uptime
The path to the command 'uptime' if different than the default.
The path to the command 'uptime' if different than the default.
(Default: /usr/bin/uptime)
Example:
@ -52,74 +53,50 @@ Steve Kemp's announcement of an alternate load limiter: http://www.nntp.perl.org
Written by Peter Eisch <peter@boku.net>.
=head1 CHANGES
v0.03 - msimerson - 2014-03-21
* refactored "find the way to get load avg" out of loadcheck (every
connection) into get_load_method which is run in register. If we can't
get the load average, don't register the hook.
* added BSD::getloadavg method (tested on FreeBSD)
v0.02 - github@rsiddall - resurrected from list archives
=cut
my $VERSION = 0.02;
my $VERSION = 0.03;
sub register {
my ($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->{_args} = { @args };
$self->{_args}{max_load} ||= 7;
$self->{_args}{uptime} ||= '/usr/bin/uptime';
$self->{_args}{cache_time} ||= 10;
$self->{_load} = -1;
$self->{_time} = 0;
$self->{_method} = $self->get_load_method();
$self->register_hook("connect", "loadcheck");
# only register the hook if we can measure load
if (ref $self->{_method} eq 'CODE') {
$self->register_hook("connect", "loadcheck");
}
}
sub loadcheck {
my ($self, $transaction) = @_;
if (time() > ($self->{_time} + $self->{_args}->{cache_time})) {
if (time() > ($self->{_time} + $self->{_args}{cache_time})) {
# cache value expired, update
$self->{_method}->();
$self->{_time} = 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} > $self->{_args}->{max_load}) {
if ($self->{_load} > $self->{_args}{max_load}) {
$self->log(LOGERROR, "local load too high: $self->{_load}");
return DENYSOFT;
}
@ -127,3 +104,55 @@ sub loadcheck {
return (DECLINED, "continuing with load: $self->{_load}");
}
sub get_load_method {
my ($self) = @_;
eval "use BSD::getloadavg;";
if (!$@) {
return sub {
require BSD::getloadavg;
$self->{_load} = (getloadavg())[0];
$self->log(LOGDEBUG, "BSD::getloadavg reported: $self->{_load}");
}
}
if (-r '/kern/loadavg') { # *BSD
return sub {
open(LD, '<', "/kern/loadavg"); # contains fix-point scaling value
my $res = <LD>;
close LD;
my @vals = split(/ /, $res);
$self->{_load} = ($vals[0] / $vals[3]);
$self->log(LOGDEBUG, "/kern/loadavg reported: $self->{_load}");
}
}
if (-r '/proc/loadavg') { # *inux
return sub {
open(LD, "<", "/proc/loadavg"); # contains decimal value
my $res = <LD>; # contains fix-point scaling value
close LD;
$self->{_load} = (split(/ /, $res))[0];
$self->log(LOGDEBUG, "/proc/loadavg reported: $self->{_load}");
}
}
if (-x $self->{_args}{uptime}) {
return sub {
# 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;
$self->log(LOGDEBUG, "$self->{_args}{uptime} reported: $self->{_load}");
}
}
}
$self->log(LOGERROR, "unable to acquire system load");
return;
};