Re: [log4perl-devel] Scripting thresholds for mod_perl

[Mike S. <m...@pe...>]

On Thu, 16 May 2013, Mark Horstmeier wrote:

> Log4perl loads with level set to ERROR per conf.  I want to set my
> appender to DEBUG Threshold was not defined in the conf so it is set
> to ALL I set the appender to DEBUG But still only the ERROR and FATAL
> levels are output

Looks like you're setting the appender's threshold when what you really
want is setting the logger's level instead. Doesn't

      my $logger = Log::Log4perl::get_logger('');

      # ...
      $logger->level( $DEBUG );

do what you have in mind?

-- -- Mike

Mike Schilli
m...@pe...

> A follow up question on thresholds I have a web app (application
> engine) that returns different mime-types depending on the  query.  I
> use a screen appender to embed the debug logs in the response (usually
> javascript, because I often return javascript for the client browser
> to execute). 
> 
> When I need to return JSON, the javascript debug 
>       // <log4perl stuff>
> 
> Blows up the JSON encoding.  
> 
> If I just use $logger->level(..) to keep the debug from leaking into my JSON
> document, I lose the debug information that is written to my file appender.
> 
> When I return javascript, embedding the debug in the javascript is very
> helpful to the people apps for my application engine so they can debug the
> creation of the javascript so I don't want to eliminate it.
> 
> I have tried to change the threshold dynamically on just one appender, but
> the log out put remains the same (I am testing this with just a file
> appender for simplicity):
>   my $logger = Log::Log4perl::get_logger('');
>     DEBUG("debug");
>     INFO("info");
>     WARN("warn");
>     ERROR("error");
>     FATAL("fatal");  
> ...
>     my $appender =  $Log::Log4perl::Logger::APPENDER_BY_NAME{$key};
>     my $dthresh = $appender->threshold();    
>     $logger->error("Appender set to: ",Log::Log4perl::Level::to_level(
> $dthresh ));
>     my $nthresh = $appender->threshold($DEBUG);
> ...
>     $logger->error("Appender set to: ",Log::Log4perl::Level::to_level(
> $n2thresh ));
>     $logger->debug("debug");
>     $logger->info("info");
>     $logger->warn("warn");
>     $logger->error("error");
>     $logger->fatal("fatal");
> 
> With my conf file:
>        log4perl.logger = ERROR, FileApp
> 
> log4perl.appender.FileApp           = Log::Log4perl::Appender::File
> log4perl.appender.FileApp.filename  = /web/logs/detail_log
> log4perl.appender.FileApp.mode = append
> log4perl.appender.FileApp.owner = web
> log4perl.appender.FileApp.group = web
> log4perl.appender.FileApp.utf8 = 1
> log4perl.appender.FileApp.layout =
> Log::Log4perl::Layout::PatternLayout
> log4perl.appender.FileApp.layout.ConversionPattern = \
> %r %X{eid} %p %F{1} %X{site} %X{rule} %m%n
> 
> Apache gives me this:
>       3 [undef] ERROR Configure.pm [undef] [undef] error
>       4 [undef] FATAL Configure.pm [undef] [undef] fatal
>       5 [undef] ERROR Configure.pm [undef] [undef] Appender set to:
>       ALL
> 
>  
>       5 [undef] ERROR Configure.pm [undef] [undef] DEBUG FileApp 
> 
>  
>       6 [undef] ERROR Configure.pm [undef] [undef] Appender set to:
>       DEBUG
>       6 [undef] ERROR Configure.pm [undef] [undef] error
>       6 [undef] FATAL Configure.pm [undef] [undef] fatal
> 
> 
...
> 
> I suppose that an alternative would be to apply a Buffer composite appender
> and only creating the trigger condition if the response type is not JSON
> 
> Should I be able to make this work via threshold or do I need to pursue an
> alternative solution?
> 
>