Dearest Monks

I built a small mod_perl handler that logs a message in a custom log file depending on the presence and the value of an HTTP header. It is named Tiscali::LogLoadBalancer and uses the Apache::LogFile module this way in httpd.conf:

PerlModule Apache::LogFile
PerlModule Apache::LogFile::Config

PerlLogFile "logs/loadbalancer.log" Tiscali::LoadBalancerLogFile

<Location />
  PerlFixuphandler Tiscali::LogLoadBalancer
</Location>
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The handler works almost well: header's values are correctly logged into the logs/loadbalancer.log file. E.g.:

Unfortunately, when the server is heavily stressed (like launching three parallel instances of the ab utility with three different values for that header) it happens quite often that two (or more!) different log messages are merged togehter, e.g.:

or

Mon Jul  9 16:53:56 2007 [25101] X-Loadbalancer: 2 (INVALID)Mon Jul  9
+ 16:53:56 2007 [25108] X-Loadbalancer: 1 (OK)Mon Jul  9 16:53:56 2007
+ [25102] X-Loadbalancer: 0 (OK)

Mon Jul  9 16:53:56 2007 [25101] X-Loadbalancer: 2 (INVALID)
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Is there any way to avoid that side effect? When I opted for an Apache::LogFile-based solution I did it also because I believed that this kind of issue was already taken care of by the author, who has a well respected name in the community. I guess I am probably doing something wrong, but I can't tell what... any help?

package Tiscali::LogLoadBalancer ;

use strict ;
use warnings ;

use Apache::Constants qw{:common} ;

sub handler {
  my ($self,$r) = @_ ;

  $r ||= Apache->request() ;

  my $status ;
  my $lb = $r->header_in( q{X-Loadbalancer} ) ;

  if (defined $lb) {
    $status = q{INVALID} ;
    $status = q{OK} if $lb == 0 ;
    $status = q{OK} if $lb == 1 ;
  } else {
    $lb     = q{UNDEF} ;
    $status = q{OK} ;
  }

  _logger($lb,$status) ;
  return DECLINED ;
}

sub _logger {
  my ($lb_value,$status) = @_ ;

  my $now = localtime ;
  my $pid = $$ ;
  my $message = qq{$now [$pid] X-Loadbalancer: $lb_value ($status)} ;
  print Tiscali::LoadBalancerLogFile $message ;
}

1 ;
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