Created
May 29, 2013 12:59
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To fix the leap second outage
More info http://serverfault.com/questions/403732/anyone-else-experiencing-high-rates-of-linux-server-crashes-during-a-leap-second
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#!/usr/bin/perl | |
use strict ; | |
use warnings ; | |
use constant DEBUG => 0 ; | |
my ($adjtimex) = grep { -f $_ } qw(/sbin/adjtimex ./adjtimex); | |
die "Need adjtimex - install or download from http://linux.brong.fastmail.fm/2012-06-30/adjtimex and put into current dir\n" | |
unless $adjtimex; | |
my $args = shift; | |
open my $cmdpipe, "$adjtimex --print |" ; | |
if (not defined $cmdpipe) { | |
die "Hell, cannot read from $adjtimex pipe" ; | |
} | |
my $status ; | |
while (my $line = <$cmdpipe>) { | |
my ($keyword,$value) = ($line =~ m/^\s*(.+): (.+)$/) ; | |
next unless $keyword eq q{status} ; | |
$status = $value ; | |
last ; | |
} | |
close ($cmdpipe); | |
if (not defined $status) { | |
die "Cannot read status from $adjtimex" ; | |
} | |
# We try to detect if a leap second is inserted (16) or deleted (32) | |
# We AND the status string with 48 (32+16) and we expect $leap to be | |
# either 0 (those bits are down), or 16 (leap second inserted), or | |
# 32 (leap second removed). Theoretically, we could also get 48, but | |
# that would mean that we are both inserting and removing a leap second | |
# at the same time, which is illogical. | |
my $leap = $status & 48 ;. | |
if ($leap == 0) { | |
# No leap set, we "fail" out | |
print "No leap, yay\n"; | |
exit 1 ; | |
} | |
if ($leap == 16 or $leap == 32) { | |
# Leap second inserted (16) or deleted (32): we must reset that bit | |
$status -= $leap ; | |
print "leap $leap, " . ($args ? "fixing\n" : "run with arg to fix\n"); | |
system($adjtimex,'--status',$status) if $args; | |
exit 0 ; | |
} | |
die "Leap bits are set to $leap, which is illogical" ; |
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