log4perl-devel — Ongoing log4perl development

[log4perl-devel] Log::Log4perl 1.20 released

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

Hi Log4perl enthusiasts,

Log4perl 1.20 has just been released to log4perl.com, here's what's new:

1.20 (2008/12/09)
     *   (ms) Using semctl to reset the value of the semaphore in the
              Synchronized appender to prevent "Numerical result out of
              range" problem caused by an unbalanced SEM_UNDO when
              incrementing it. Reported by John Little.
     *   (ms) Added parameters in curly braces to cspecs in PatternLayout.
     *   (ms) As explained in
                 http://rt.cpan.org/Ticket/Display.html?id=41505
              the latest LWP release (5.822) got rid of all of its
              internal debugging functions, making infiltrate_lwp() and
              its test case useless. Disabling it for LWP>=5.822.

If all goes well, it'll go to CPAN in a couple of days.

-- Mike

Mike Schilli
m...@pe...

Re: [log4perl-devel] Test-Failure on Solaris 10 with perl 5.10.0

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

On Tue, 9 Dec 2008, Mike Schilli wrote:

> Interesting, which version of LWP::UserAgent do you have installed?

Never mind, I found it, it's caused by the latest LWP release (5.822),
which got rid of all of its internal debugging functions. I'll fix the
Log4perl test suite to omit this test in case LWP>=5.822 is installed.

Thanks for your report!

-- Mike

Mike Schilli
m...@pe...

>
> -- Mike
>
> Mike Schilli
> m...@pe...

> On Tue, 9 Dec 2008, Martin Armbrecht wrote:
>
>> I just tried to install Log::Log4perl on Solaris 10 (SPARC) with Perl
>> 5.10.0 and ran into the test failure below.
>>
>> t/048lwp.............1/3 #   Failed test at t/048lwp.t line 45.
>> #                   '' #     doesn't match '(?-xism:GET\
>> file\:\/tmp\/l4p\-tmpfile\-5804\-3150241)'

Re: [log4perl-devel] Test-Failure on Solaris 10 with perl 5.10.0

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

On Tue, 9 Dec 2008, Martin Armbrecht wrote:

> I just tried to install Log::Log4perl on Solaris 10 (SPARC) with Perl
> 5.10.0 and ran into the test failure below.
>
> t/048lwp.............1/3 #   Failed test at t/048lwp.t line 45.
> #                   '' #     doesn't match '(?-xism:GET\
> file\:\/tmp\/l4p\-tmpfile\-5804\-3150241)'

Interesting, which version of LWP::UserAgent do you have installed?

-- Mike

Mike Schilli
m...@pe...

>
> #   Failed test at t/048lwp.t line 90.
> #                   ''
> #     doesn't match '(?-xism:LWP/UserAgent.pm-\d+)'
> # Looks like you failed 2 tests of 3.
> t/048lwp............. Dubious, test returned 2 (wstat 512, 0x200)
> Failed 2/3 subtests
> t/049Unhide..........ok
> t/050Buffer..........ok
> t/051Extra...........ok
> t/052Utf8............ok
> t/053Resurrect.......ok
> t/054Subclass........ok
> t/055AppDestroy......ok
>
> Test Summary Report
> -------------------
> t/048lwp         (Wstat: 512 Tests: 3 Failed: 2)
>  Failed tests:  1, 3
>  Non-zero exit status: 2
> Files=56, Tests=604, 43 wallclock secs ( 1.00 usr  0.46 sys + 16.76 cusr  1.71
> csys = 19.93 CPU)
> Result: FAIL
> Failed 1/56 test programs. 2/604 subtests failed.
> make: *** [test_dynamic] Error 255
>  MSCHILLI/Log-Log4perl-1.19.tar.gz
>  /usr/local/bin/make test -- NOT OK
> //hint// to see the cpan-testers results for installing this module, try:
>  reports MSCHILLI/Log-Log4perl-1.19.tar.gz
> Running make install
>  make test had returned bad status, won't install without force
> Failed during this command:
> MSCHILLI/Log-Log4perl-1.19.tar.gz            : make_test NO
> --->8---
>
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[log4perl-devel] Test-Failure on Solaris 10 with perl 5.10.0

[Martin A. <arm...@hb...>]

Hi,
I just tried to install Log::Log4perl on Solaris 10 (SPARC) with Perl 5.10.0 
and ran into the test failure below.

Any hints?

Regards
	Martin

---8<---
Running make test
PERL_DL_NONLAZY=1 /files/tools/bin/perl "-MExtUtils::Command::MM" "-e" "test_harness(0, 'blib/lib', 'blib/arch')" 
t/*.t
t/001Level...........ok
t/002Logger..........ok
t/003Layout..........ok
t/004Config..........ok
t/005Config-Perl.....ok
t/006Config-Java.....skipped: only with Log::Dispatch
t/007LogPrio.........ok
t/008ConfCat.........ok
t/009Deuce...........ok
t/010JConsole........skipped: only with Log::Dispatch
t/011JFile...........skipped: only with Log::Dispatch
t/012Deeper..........skipped: only with Log::Dispatch
t/013Bench...........ok
t/014ConfErrs........ok
t/015fltmsg..........ok
t/016Export..........ok
t/017Watch...........ok
t/018Init............ok
t/019Warn............ok
t/020Easy............ok
t/020Easy2...........ok
t/021AppThres........ok
t/022Wrap............ok
t/023Date............ok
t/024WarnDieCarp.....ok
t/025CustLevels......ok
t/026FileApp.........ok
t/027Watch2..........ok
t/027Watch3..........ok
t/028Additivity......ok
t/029SysWide.........ok
t/030LDLevel.........ok
t/031NDC.............ok
t/032JRollFile.......skipped: only with Log::Dispatch::FileRotate 1.10
t/033UsrCspec........ok
t/034DBI.............skipped: DBD::CSV or SQL::Statement 1.005 not installed, 
skipping tests
t/035JDBCAppender....skipped: only with Log::Dispatch and DBD::CSV
t/036JSyslog.........ok
t/037JWin32Event.....skipped: only with Log::Dispatch::Win32EventLog
t/038XML-DOM1........skipped: only with XML::DOM > 1.29
t/039XML-DOM2........skipped: only with XML::DOM > 1.29
t/040Filter..........ok
t/041SafeEval........ok
t/042SyncApp.........skipped: - only with L4P_ALL_TESTS
t/043VarSubst........ok
t/044XML-Filter......skipped: only with XML::DOM > 1.29
t/045Composite.......ok
t/046RRDs............skipped: (RRDs not installed)
t/048lwp.............1/3
#   Failed test at t/048lwp.t line 45.
#                   ''
#     doesn't match '(?-xism:GET\ file\:\/tmp\/l4p\-tmpfile\-5804\-3150241)'

#   Failed test at t/048lwp.t line 90.
#                   ''
#     doesn't match '(?-xism:LWP/UserAgent.pm-\d+)'
# Looks like you failed 2 tests of 3.
t/048lwp............. Dubious, test returned 2 (wstat 512, 0x200)
 Failed 2/3 subtests
t/049Unhide..........ok
t/050Buffer..........ok
t/051Extra...........ok
t/052Utf8............ok
t/053Resurrect.......ok
t/054Subclass........ok
t/055AppDestroy......ok

Test Summary Report
-------------------
t/048lwp         (Wstat: 512 Tests: 3 Failed: 2)
  Failed tests:  1, 3
  Non-zero exit status: 2
Files=56, Tests=604, 43 wallclock secs ( 1.00 usr  0.46 sys + 16.76 cusr  1.71 
csys = 19.93 CPU)
Result: FAIL
Failed 1/56 test programs. 2/604 subtests failed.
make: *** [test_dynamic] Error 255
  MSCHILLI/Log-Log4perl-1.19.tar.gz
  /usr/local/bin/make test -- NOT OK
//hint// to see the cpan-testers results for installing this module, try:
  reports MSCHILLI/Log-Log4perl-1.19.tar.gz
Running make install
  make test had returned bad status, won't install without force
Failed during this command:
 MSCHILLI/Log-Log4perl-1.19.tar.gz            : make_test NO
--->8---

Re: [log4perl-devel] Sending SMTP Mail via Log4Perl

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

On Thu, 20 Nov 2008, Matthias Weiser wrote:

> I am following the FAQs and try to send SMTP mail via Log4Perl.
> I first tried this configuration:
>
> log4perl.category = FATAL, Mailer
> log4perl.appender.Mailer = Log::Dispatch::Email::MailSend
> log4perl.appender.Mailer.to = x@z.com
> log4perl.appender.Mailer.from = y@z.com
> log4perl.appender.Mailer.subject = Something's broken!
> log4perl.appender.Mailer.layout = SimpleLayout
> log4perl.appender.Mailer.Server = x.x.x.x
> log4perl.appender.Mailer.smtp = 1
> log4perl.appender.Mailer.buffer=0

Hi Matthias,

it looks good to me, I just verified that it works with my SMTP server.

> This did not work as smtp is a scalar reference in the constructor of
> Mail::Mailer and log4perl seems to call it only with hashes.

Not sure what you're using, but my Mail::Mailer's constructor looks like

     $mailer = Mail::Mailer->new($type, @args);

so there's no references, and that's how I think the code in
Log::Dispatch::Email::MailSend uses it as well.

> Then I tried the suggestion of the module desciption for
> Log::Dispatch::Email::MailSend and tried "use Mail::Mailer 'smtp',
> Server => 'foo.example.com';" which did not work either. (Cannot
> locate 'Server' at log4Perl.pl line 1 Warning: something's wrong at
> /opt/ActivePerl-5.8/site/lib/Mail/Mailer.pm line 278).

Hmm, your version of Mail::Mailer seems to be different from the one on
CPAN -- which one are you using?

-- Mike

Mike Schilli
m...@pe...

[log4perl-devel] Sending SMTP Mail via Log4Perl

[Matthias W. <mat...@ya...>]

Hello,
I am following the FAQs and try to send SMTP mail via Log4Perl.
I first tried this configuration:

log4perl.category = FATAL, Mailer
log4perl.appender.Mailer = Log::Dispatch::Email::MailSend
log4perl.appender.Mailer.to = x@z.com
log4perl.appender.Mailer.from = y@z.com
log4perl.appender.Mailer.subject = Something's broken!
log4perl.appender.Mailer.layout = SimpleLayout
log4perl.appender.Mailer.Server = x.x.x.x
log4perl.appender.Mailer.smtp = 1
log4perl.appender.Mailer.buffer=0

This did not work as smtp is a scalar reference in the constructor of Mail::Mailer and log4perl seems to call it only with hashes.

Then I tried the suggestion of the module desciption for Log::Dispatch::Email::MailSend
 and tried 
"use Mail::Mailer 'smtp', Server => 'foo.example.com';" which did not work either. (Cannot locate 'Server' at log4Perl.pl line 1
Warning: something's wrong at /opt/ActivePerl-5.8/site/lib/Mail/Mailer.pm line 278).

If possible I would like to avoid writing my own appender.
Does someone use Log4Perl with SMTP and can help me?

Thanks in advance,

Matthias



      

Re: [log4perl-devel] Log::Log4perl MDC at object level

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

On Wed, 12 Nov 2008, Anatoliy wrote:

> I'm going to use POE library for performing multitasks and I'd like to
> use POEs session specific values in the MDC.
>
> POE doesn't use threads/processes, so I can't make it with global variables.
> Is there any thing equal to MDC but for using with $logger object? not
> Log::Log4perl class. Thank you for Log::Log4perl anyway :)

You're welcome, and that's a very good question, I've added an anwer to
the FAQ and made some changes to Log4perl:

=head2 How can I access POE heap values from Log4perl's layout?

POE is a framework for creating multitasked applications running in a
single process and a single thread. POE's threads equivalents are
'sessions' and since they run quasi-simultaneously, you can't use
Log4perl's global NDC/MDC to hold session-specific data.

However, POE already maintains a data store for every session. It is called
'heap' and is just a hash storing session-specific data in key-value pairs.
To access this per-session heap data from a Log4perl layout, define a
custom cspec and reference it with the newly defined pattern in the layout:

     use strict;
     use POE;
     use Log::Log4perl qw(:easy);

     Log::Log4perl->init( \ q{
         log4perl.logger = DEBUG, Screen
         log4perl.appender.Screen = Log::Log4perl::Appender::Screen
         log4perl.appender.Screen.layout = PatternLayout
         log4perl.appender.Screen.layout.ConversionPattern = %U %m%n
         log4perl.PatternLayout.cspec.U = \
             sub { POE::Kernel->get_active_session->get_heap()->{ user } }
     } );

     for (qw( Huey Lewey Dewey )) {
         POE::Session->create(
             inline_states => {
                 _start    => sub {
                     $_[HEAP]->{user} = $_;
                     POE::Kernel->yield('hello');
                 },
                 hello     => sub {
                     DEBUG "I'm here now";
                 }
             }
         );
     }

     POE::Kernel->run();
     exit;

The code snippet above defines a new layout placeholder (called
'cspec' in Log4perl) %U which calls a subroutine, retrieves the active
session, gets its heap and looks up the entry specified ('user').

Starting with Log::Log4perl 1.20, cspecs also support parameters in 
curly braces, so you can say

     log4perl.appender.Screen.layout.ConversionPattern = %U{user} %U{id} %m%n
     log4perl.PatternLayout.cspec.U = \
             sub { POE::Kernel->get_active_session-> \
                   get_heap()->{ $_[0]->{curlies} } }

and print the POE session heap entries 'user' and 'id' with every logged
message. For more details on cpecs, read the PatternLayout manual.

Hope that helps!

-- Mike

Mike Schilli
m...@pe...

Re: [log4perl-devel] A threading question

[John L. <joh...@gm...>]

Hi

Of course, that should be

my $main_tid = threads->tid;
sub propagate_hup {
   if (threads->tid == $main_tid) {
       for my $t (threads->list) { $t->kill('HUP') unless $t->tid ==
$main_tid; }
   }
   return 1;
}

Regards, John

Re: [log4perl-devel] A threading question

[John L. <joh...@gm...>]

Mike, all,

> A simple fix is:
>
> Log::Log4perl->init_and_watch("dllog.conf", 'HUP',
>                                {preinit_callback => \&propagate_hup} );
> sub propagate_hup {
>    for my $t (threads->list) { $t->kill('HUP'); }
>    return 1;
> }

A little too simple upon reflection; I don't know why it didn't chase
its tail indefinitely.  Better:

my $main_tid = threads->tid;
sub propagate_hup {
    if (threads->tid == $main_tid) {
        for my $t (threads->list) { $t->kill('HUP') unless $t-> == $main_tid; }
    }
    return 1;
}

Regards, John

Re: [log4perl-devel] A threading question

[John L. <joh...@gm...>]

Mike

> Can you provide code to reproduce the problem? I'd be happy to track it
> down.

I haven't been able to reproduce the strife I was having; most use of
signals was failing.

However, there is the obvious.  My perl 5.10 is delivering all OS
signals to the 'main' thread, so the logger in it gets the HUP but not
the others (cloned from the first by the threads mechanism).  A simple
fix is:

Log::Log4perl->init_and_watch("dllog.conf", 'HUP',
                                {preinit_callback => \&propagate_hup} );
sub propagate_hup {
    for my $t (threads->list) { $t->kill('HUP'); }
    return 1;
}

I'll use this and report any trouble.

Regards, John

Re: [log4perl-devel] A threading question

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

On Sat, 8 Nov 2008, John Little wrote:

> Which reminds me, I couldn't get init_and_watch($conf_file, 'HUP') to
> work with threads, which is not surprising, given that perl threads
> and signals don't mix very well.

Can you provide code to reproduce the problem? I'd be happy to track it
down.

-- Mike

Mike Schilli
m...@pe...

Re: [log4perl-devel] A threading question

[John L. <joh...@gm...>]

Mike

> Got it, ... , it'll roll out with the next release (1.20).

Thank you!

> By the way, have you tried using the 'syswrite' option of the file
> appender instead? It prevents overlapping messages as well and it's
> easier to use than the synchronizing appender:
>
>    log4perl.appender.Logfile.syswrite  = 1

No,  didn't know about that.  A colleague's been testing with the
synchronizer removed, at about 15 messages per second, with no
overwriting so far, which is what I'd expected on Linux initially.
The next restart will pick up the syswrite option above.

Which reminds me, I couldn't get init_and_watch($conf_file, 'HUP') to
work with threads, which is not surprising, given that perl threads
and signals don't mix very well.

Regards, John

Re: [log4perl-devel] A threading question

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

On Sat, 8 Nov 2008, John Little wrote:

> I've tried using Log4perl in a multi-threaded server script and the
> synchronized appender fails consistently after logging exactly 32768
> lines, with (piped through cat -v): Thread 1 terminated abnormally:
> semop(1343496 ^@^@^@^@^@^@^@^@^A^@^@^P) failed: Numerical result out
> of range  at

Got it, it's not really related to threads, there was a bug in the
semaphore code that caused this, I've fixed it in CVS, it'll roll out
with the next release (1.20).

By the way, have you tried using the 'syswrite' option of the file
appender instead? It prevents overlapping messages as well and it's
easier to use than the synchronizing appender:

     log4perl.appender.Logfile.syswrite  = 1

     http://search.cpan.org/dist/Log-Log4perl/lib/Log/Log4perl/FAQ.pm#How_can_I_synchronize_access_to_an_appender

-- Mike

Mike Schilli
m...@pe...

[log4perl-devel] A threading question

[John L. <joh...@gm...>]

Mike Schilli said:

> It would be great if you could provide test results / bug reports of
> running Log4perl with Perl threads, though.
>
> That being said, there are synchronization mechanisms for file
> appenders:
>
> http://log4perl.sourceforge.net/d/Log/Log4perl/FAQ.html#23804

I've tried using Log4perl in a multi-threaded server script and the
synchronized appender fails consistently after logging exactly 32768 lines,
with (piped through cat -v):

Thread 1 terminated abnormally: semop(1343496
^@^@^@^@^@^@^@^@^A^@^@^P) failed: Numerical result out of range  at
/usr/local/lib/perl5/site_perl/5.10.0/Log/Log4perl/Util/Semaphore.pm
line 192, <GEN3277> chunk 2.
semop(1343496 ^@^@^@^@^@^@^@^@^A^@^@^P) failed: Numerical result out
of range  at /usr/local/lib/perl5/site_perl/5.10.0/Log/Log4perl/Util/Semaphore.pm
line 192.

OS is CentOS 5.2 under xen.  In one case there were three threads.  Without
using the synchronized appender, in heavy testing overwrites occurred.  I'll
try to replicate the failure in my test environment (Kubuntu 8.04).

Regards, John

Re: [log4perl-devel] Sending email of logs only on failure

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

On Thu, 6 Nov 2008, Mathieu Longtin wrote:

> I have a program that processes a bunch of separate items, logging stuff as
> it goes. I would like to be able to capture what gets logged during the
> processing on one item, and email the whole thing if the processing failed.
> The log messages should go to a file regardless.
>
> Is there a way to do that in log4perl currently?

You could use one of the Log::Dispatch::Email::* modules on CPAN and set
it to 'buffered':

      http://search.cpan.org/dist/Log-Log4perl/lib/Log/Log4perl/FAQ.pm#How_can_I_configure_Log::Log4perl_to_send_me_email_if_something_happens?

When it is time to flush it, retrieve the appender by name and call its
flush() method.

But I'd probably just use Log4perl to write everything to a log file
(use overwrite mode to start a new log file every time) and at the end
of the program run a check and send off the logfile via a CPAN module
like Mail::DWIM.

-- Mike

Mike Schilli
m...@pe...

[log4perl-devel] Sending email of logs only on failure

[Mathieu L. <ma...@cl...>]

I have a program that processes a bunch of separate items, logging stuff as
it goes. I would like to be able to capture what gets logged during the
processing on one item, and email the whole thing if the processing failed.
The log messages should go to a file regardless.

Is there a way to do that in log4perl currently?

Thanks

--
Mathieu Longtin
1-514-803-8977

[log4perl-devel] Delayed email appender

[Mathieu L. <ma...@cl...>]

I have a program that processes a bunch of separate items, logging stuff as
it goes. I would like to be able to capture what gets logged during the
processing on one item, and email the whole thing if the processing failed.

Is there a way to do that in log4perl currently?

--
Mathieu Longtin
1-514-803-8977

Re: [log4perl-devel] Wide Character errors

[John L. <joh...@gm...>]

Bill Moseley got "Wide character in" errors.

I encountered this a few days ago.  I've found it hard to reproduce.
It seems perl has a "Don't ask, don't tell" attitude, but once you've
got the utf8 bit set on some data then it worries about it thereafter.

The ".utf8 = 1" directive only works for the File appender.  See
perldoc Log::Log4perl::FAQ.

Using

    binmode STDERR, ":utf8";

avoids the wide character errors for the screen appender.  You could try

    binmode SYSLOG, ":utf8";

as the only calls to syswrite in Sys/Syslog.pm are to SYSLOG.

Regards, John

Re: [log4perl-devel] activating appenders

[Erskine, T. \(IT\) <Tho...@mo...>]

That's got it.  Thanks muchly.

Thomas Erskine
Consultant | Technology
2000 Barrington St | Suite 300 | Floor 04
Halifax, NS B3J3K1
Phone: +1 902 442-4709
Tho...@mo...
 

> -----Original Message-----
> From: Mike Schilli [mailto:m...@pe...] 
> Sent: Thursday, October 30, 2008 3:19 PM
> To: Erskine, Thomas (IT)
> Cc: Mike Schilli; log...@li...
> Subject: RE: [log4perl-devel] activating appenders
> 
> On Thu, 30 Oct 2008, Erskine, Thomas (IT) wrote:
> 
> > The problem with setting a threshold on the appender to 
> cause it not 
> > ot log is that I don't see a way to programmatically set 
> the threshold 
> > to a specific level.  It can be bumped up or down, but that 
> requires 
> > the program to know where the threshold was set in the 
> configuration.
> > I.E.  configuration in the program, which I'm trying to avoid.
> 
> It's a bit tricky because you need access to Log4perl's 
> appender wrapper, not the appender itself:
> 
> "The previously mentioned method "appender_by_name()" returns 
> a refer- rence to the real appender object. If you want 
> access to the wrapper class (e.g. if you want to modify the 
> appender’s threshold), use the hash 
> $Log::Log4perl::Logger::APPENDER_BY_NAME{...} instead, which 
> holds references all appender wrapper objects." [perldoc 
> Log::Log4perl]
> 
> So, if you have a disabled appender like
> 
>      log4perl.appender.SCREEN=Log::Log4perl::Appender::Screen
>      log4perl.appender.SCREEN.layout = SimpleLayout
>      log4perl.appender.SCREEN.Threshold = OFF
> 
> in your configuration, you can retrieve its threshold setting via
> 
>      my $app = $Log::Log4perl::Logger::APPENDER_BY_NAME{"SCREEN"};
>      my $threshold = $app->threshold();
> 
> and print it out like
> 
>      print "Threshold set to ",
>            Log::Log4perl::Level::to_level( $threshold ),
>            "\n";
> 
> If you want to enable the appender, set
> 
>      $threshold = $app->threshold( $ALL );
> 
> If you want to disable it again, set
> 
>      $threshold = $app->threshold( $OFF );
> 
> -- Mike
> 
> Mike Schilli
> m...@pe...
> 
> >
> > The best I've been able to come up with is to define a 
> logger with a 
> > threshold which won't log, call it deactivated, and assign this 
> > appender to it.  Then to activate this appender, I can use 
> > appender_by_name(...) and get_root_logger()->add_appender(...).  It 
> > took me a while to find it as get_root_logger is only defined on 
> > Log::Log4perl::Logger, not in Log::Log4perl.
> >
> > Thomas Erskine
> > Consultant | Technology
> > 2000 Barrington St | Suite 300 | Floor 04 Halifax, NS B3J3K1
> > Phone: +1 902 442-4709
> > Tho...@mo...
> >
> >
> >> -----Original Message-----
> >> From: Mike Schilli [mailto:m...@pe...]
> >> Sent: Wednesday, October 29, 2008 5:29 PM
> >> To: Erskine, Thomas (IT)
> >> Cc: log...@li...
> >> Subject: Re: [log4perl-devel] activating appenders
> >>
> >> On Wed, 29 Oct 2008, Erskine, Thomas (IT) wrote:
> >>
> >>> I want to be able to define an appender in the log4perl
> >> config file,
> >>> but not activated and then activate it programmatically However,
> >>> Log::Log4perl->appender_by_name('SCREENDEBUG') returns undef.
> >>>
> >>> I guess I could add SCREENDEBUG to the log4perl.logger line
> >> and define
> >>> it with a threshold which won't log anything and then bump the
> >>> threshold up at runtime, but it seems wrong somehow.
> >>
> >> An appender that's not assigned to any logger in the
> >> configuration is ignored by Log4perl at this point -- I think
> >> that using a threshold, as you've suggested, is a perfectly
> >> valid solution, though.
> >>
> >> Alternatively, you can define the appender programmatically
> >> and add it to the logger via add_appender().
> >>
> >> -- Mike
> >>
> >> Mike Schilli
> >> m...@pe...
> >>
> > --------------------------------------------------------
> >
> > NOTICE: If received in error, please destroy and notify 
> sender. Sender does not intend to waive confidentiality or 
> privilege. Use of this email is prohibited when received in error.
> >
>
--------------------------------------------------------

NOTICE: If received in error, please destroy and notify sender. Sender does not intend to waive confidentiality or privilege. Use of this email is prohibited when received in error.

Re: [log4perl-devel] activating appenders

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

On Thu, 30 Oct 2008, Erskine, Thomas (IT) wrote:

> The problem with setting a threshold on the appender to cause it not
> ot log is that I don't see a way to programmatically set the threshold
> to a specific level.  It can be bumped up or down, but that requires
> the program to know where the threshold was set in the configuration.
> I.E.  configuration in the program, which I'm trying to avoid.

It's a bit tricky because you need access to Log4perl's appender
wrapper, not the appender itself:

"The previously mentioned method "appender_by_name()" returns a refer-
rence to the real appender object. If you want access to the wrapper
class (e.g. if you want to modify the appender’s threshold), use the
hash $Log::Log4perl::Logger::APPENDER_BY_NAME{...} instead, which holds
references all appender wrapper objects." [perldoc Log::Log4perl]

So, if you have a disabled appender like

     log4perl.appender.SCREEN=Log::Log4perl::Appender::Screen
     log4perl.appender.SCREEN.layout = SimpleLayout
     log4perl.appender.SCREEN.Threshold = OFF

in your configuration, you can retrieve its threshold setting via

     my $app = $Log::Log4perl::Logger::APPENDER_BY_NAME{"SCREEN"};
     my $threshold = $app->threshold();

and print it out like

     print "Threshold set to ",
           Log::Log4perl::Level::to_level( $threshold ),
           "\n";

If you want to enable the appender, set

     $threshold = $app->threshold( $ALL );

If you want to disable it again, set

     $threshold = $app->threshold( $OFF );

-- Mike

Mike Schilli
m...@pe...

>
> The best I've been able to come up with is to define a logger with a
> threshold which won't log, call it deactivated, and assign this appender
> to it.  Then to activate this appender, I can use appender_by_name(...)
> and get_root_logger()->add_appender(...).  It took me a while to find it
> as get_root_logger is only defined on Log::Log4perl::Logger, not in
> Log::Log4perl.
>
> Thomas Erskine
> Consultant | Technology
> 2000 Barrington St | Suite 300 | Floor 04
> Halifax, NS B3J3K1
> Phone: +1 902 442-4709
> Tho...@mo...
>
>
>> -----Original Message-----
>> From: Mike Schilli [mailto:m...@pe...]
>> Sent: Wednesday, October 29, 2008 5:29 PM
>> To: Erskine, Thomas (IT)
>> Cc: log...@li...
>> Subject: Re: [log4perl-devel] activating appenders
>>
>> On Wed, 29 Oct 2008, Erskine, Thomas (IT) wrote:
>>
>>> I want to be able to define an appender in the log4perl
>> config file,
>>> but not activated and then activate it programmatically However,
>>> Log::Log4perl->appender_by_name('SCREENDEBUG') returns undef.
>>>
>>> I guess I could add SCREENDEBUG to the log4perl.logger line
>> and define
>>> it with a threshold which won't log anything and then bump the
>>> threshold up at runtime, but it seems wrong somehow.
>>
>> An appender that's not assigned to any logger in the
>> configuration is ignored by Log4perl at this point -- I think
>> that using a threshold, as you've suggested, is a perfectly
>> valid solution, though.
>>
>> Alternatively, you can define the appender programmatically
>> and add it to the logger via add_appender().
>>
>> -- Mike
>>
>> Mike Schilli
>> m...@pe...
>>
> --------------------------------------------------------
>
> NOTICE: If received in error, please destroy and notify sender. Sender does not intend to waive confidentiality or privilege. Use of this email is prohibited when received in error.
>

Re: [log4perl-devel] activating appenders

[Erskine, T. \(IT\) <Tho...@mo...>]

Hi Mike.

According to the docs, it ought to have worked but it doesn't.

I've got a config like:
------ begin config ------
layout = %d{yyyy-MM-ddTHH:mm:ss} %P %p %c %H %m%n

# Assign various things to various appenders
log4perl.rootlogger                 = TRACE, FILE, SCREEN
log4perl.logger.deactivated         = OFF, SCREENDEBUG

# Log everything to a file
log4perl.appender.FILE              = Log::Log4perl::Appender::File
log4perl.appender.FILE.filename     = sub { main::get_log_name(); }
log4perl.appender.FILE.mode         = clobber
log4perl.appender.FILE.Threshold    = TRACE
log4perl.appender.FILE.layout       =
Log::Log4perl::Layout::PatternLayout
log4perl.appender.FILE.layout.ConversionPattern       = FILE ${layout}

log4perl.appender.SCREEN            = Log::Log4perl::Appender::Screen
log4perl.appender.SCREEN.Threshold  = ERROR
log4perl.appender.SCREEN.layout     =
Log::Log4perl::Layout::PatternLayout
log4perl.appender.SCREEN.layout.ConversionPattern     = SCREEN ${layout}

log4perl.appender.SCREENDEBUG            =
Log::Log4perl::Appender::ScreenColoredLevels
log4perl.appender.SCREENDEBUG.layout     =
Log::Log4perl::Layout::PatternLayout
log4perl.appender.SCREENDEBUG.layout.ConversionPattern     = SCREENDEBUG
${layout}
------ end ------

The code looks like:
------ begin code ------
Log::Log4perl::init_and_watch($CONFIG_FILE, 10);

my $logger = Log::Log4perl->get_logger();
if ( $screen eq 'SCREENDEBUG' ) {
    my $app = Log::Log4perl->appender_by_name('SCREENDEBUG');
    $logger->add_appender($app);
    eval {
        $app = Log::Log4perl->appender_by_name('SCREEN');
        Log::Log4perl::Logger->get_root_logger()->remove_appender($app);
    };
    if ($@) { warn("can't remove SCREEN appender: $@"); }
}

The first part (adding SCREENDEBUG workd; the second doesn't.  The error
I get is:
can't remove SCREEN appender: No such appender:
Log::Log4perl::Appender::Screen=HASH(0x843cf28) at
//ms/dist/perl5/PROJ/Log-Log4perl/1.13/lib/perl5/Log/Log4perl/Logger.pm
line 607.

Which is strange as, running under the debugger, I can see both
appenders listed in the root logger.  Any ideas?

------ end ------

Thomas Erskine
Consultant | Technology
2000 Barrington St | Suite 300 | Floor 04
Halifax, NS B3J3K1
Phone: +1 902 442-4709
Tho...@mo...
 

> -----Original Message-----
> From: Erskine, Thomas (IT) 
> Sent: Thursday, October 30, 2008 12:03 PM
> To: 'Mike Schilli'
> Cc: log...@li...
> Subject: RE: [log4perl-devel] activating appenders
> 
> Hi Mike.
> 
> I want to have the appender defined in the configuration for 
> doccumentation and because having log configuration external 
> to the program is (at least) half the point of a logging system IMHO.
> 
> The problem with setting a threshold on the appender to cause 
> it not ot log is that I don't see a way to programmatically 
> set the threshold to a specific level.  It can be bumped up 
> or down, but that requires the program to know where the 
> threshold was set in the configuration.  I.E. configuration 
> in the program, which I'm trying to avoid.
> 
> The best I've been able to come up with is to define a logger 
> with a threshold which won't log, call it deactivated, and 
> assign this appender to it.  Then to activate this appender, 
> I can use appender_by_name(...) and 
> get_root_logger()->add_appender(...).  It took me a while to 
> find it as get_root_logger is only defined on 
> Log::Log4perl::Logger, not in Log::Log4perl.
> 
> Thomas Erskine
> Consultant | Technology
> 2000 Barrington St | Suite 300 | Floor 04 Halifax, NS B3J3K1
> Phone: +1 902 442-4709
> Tho...@mo...
>  
> 
> > -----Original Message-----
> > From: Mike Schilli [mailto:m...@pe...]
> > Sent: Wednesday, October 29, 2008 5:29 PM
> > To: Erskine, Thomas (IT)
> > Cc: log...@li...
> > Subject: Re: [log4perl-devel] activating appenders
> > 
> > On Wed, 29 Oct 2008, Erskine, Thomas (IT) wrote:
> > 
> > > I want to be able to define an appender in the log4perl
> > config file,
> > > but not activated and then activate it programmatically However,
> > > Log::Log4perl->appender_by_name('SCREENDEBUG') returns undef.
> > >
> > > I guess I could add SCREENDEBUG to the log4perl.logger line
> > and define
> > > it with a threshold which won't log anything and then bump the 
> > > threshold up at runtime, but it seems wrong somehow.
> > 
> > An appender that's not assigned to any logger in the 
> configuration is 
> > ignored by Log4perl at this point -- I think that using a 
> threshold, 
> > as you've suggested, is a perfectly valid solution, though.
> > 
> > Alternatively, you can define the appender programmatically 
> and add it 
> > to the logger via add_appender().
> > 
> > -- Mike
> > 
> > Mike Schilli
> > m...@pe...
> >
--------------------------------------------------------

NOTICE: If received in error, please destroy and notify sender. Sender does not intend to waive confidentiality or privilege. Use of this email is prohibited when received in error.

Re: [log4perl-devel] activating appenders

[Erskine, T. \(IT\) <Tho...@mo...>]

Hi Mike.

I want to have the appender defined in the configuration for
doccumentation and because having log configuration external to the
program is (at least) half the point of a logging system IMHO.

The problem with setting a threshold on the appender to cause it not ot
log is that I don't see a way to programmatically set the threshold to a
specific level.  It can be bumped up or down, but that requires the
program to know where the threshold was set in the configuration.  I.E.
configuration in the program, which I'm trying to avoid.

The best I've been able to come up with is to define a logger with a
threshold which won't log, call it deactivated, and assign this appender
to it.  Then to activate this appender, I can use appender_by_name(...)
and get_root_logger()->add_appender(...).  It took me a while to find it
as get_root_logger is only defined on Log::Log4perl::Logger, not in
Log::Log4perl.

Thomas Erskine
Consultant | Technology
2000 Barrington St | Suite 300 | Floor 04
Halifax, NS B3J3K1
Phone: +1 902 442-4709
Tho...@mo...
 

> -----Original Message-----
> From: Mike Schilli [mailto:m...@pe...] 
> Sent: Wednesday, October 29, 2008 5:29 PM
> To: Erskine, Thomas (IT)
> Cc: log...@li...
> Subject: Re: [log4perl-devel] activating appenders
> 
> On Wed, 29 Oct 2008, Erskine, Thomas (IT) wrote:
> 
> > I want to be able to define an appender in the log4perl 
> config file, 
> > but not activated and then activate it programmatically However,
> > Log::Log4perl->appender_by_name('SCREENDEBUG') returns undef.
> >
> > I guess I could add SCREENDEBUG to the log4perl.logger line 
> and define 
> > it with a threshold which won't log anything and then bump the 
> > threshold up at runtime, but it seems wrong somehow.
> 
> An appender that's not assigned to any logger in the 
> configuration is ignored by Log4perl at this point -- I think 
> that using a threshold, as you've suggested, is a perfectly 
> valid solution, though.
> 
> Alternatively, you can define the appender programmatically 
> and add it to the logger via add_appender().
> 
> -- Mike
> 
> Mike Schilli
> m...@pe...
>
--------------------------------------------------------

NOTICE: If received in error, please destroy and notify sender. Sender does not intend to waive confidentiality or privilege. Use of this email is prohibited when received in error.

Re: [log4perl-devel] activating appenders

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

On Wed, 29 Oct 2008, Erskine, Thomas (IT) wrote:

> I want to be able to define an appender in the log4perl config file,
> but not activated and then activate it programmatically However,
> Log::Log4perl->appender_by_name('SCREENDEBUG') returns undef.
>
> I guess I could add SCREENDEBUG to the log4perl.logger line and define
> it with a threshold which won't log anything and then bump the threshold
> up at runtime, but it seems wrong somehow.

An appender that's not assigned to any logger in the configuration is
ignored by Log4perl at this point -- I think that using a threshold, as
you've suggested, is a perfectly valid solution, though.

Alternatively, you can define the appender programmatically and add it
to the logger via add_appender().

-- Mike

Mike Schilli
m...@pe...

[log4perl-devel] activating appenders

[Erskine, T. \(IT\) <Tho...@mo...>]

Hi folks.
 
I want to be able to define an appender in the log4perl config file, but
not activated and then activate it programmatically.  I.E.  I have:
 
log4perl.logger = TRACE, FILE, SCREEN
log4perl.appender.FILE = Log::Log4perl::Appender::File
... [definition snipped]
log4perl.appender.SCREEN = Log::Log4perl::Appender::Screen
... [definition snipped]
log4perl.appender.SCREENDEBUG =
Log::Log4perl::Appender::ScreenColoredLevels
... [definition snipped]
 
However, Log::Log4perl->appender_by_name('SCREENDEBUG') returns undef.
 
I guess I could add SCREENDEBUG to the log4perl.logger line and define
it with a threshold which won't log anything and then bump the threshold
up at runtime, but it seems wrong somehow.
 
Is there a way to do this, using the public API, or am I stuck with
diddling the threshiold?
 
Thomas Erskine
Consultant | Technology
2000 Barrington St | Suite 300 | Floor 04
Halifax, NS B3J3K1
Phone: +1 902 442-4709
Tho...@mo...
--------------------------------------------------------

NOTICE: If received in error, please destroy and notify sender. Sender does not intend to waive confidentiality or privilege. Use of this email is prohibited when received in error.

[log4perl-devel] Log::Log4perl 1.19 released

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

Hi Log4perl enthusiasts,

the 1.19 maintenance release has just hit the website. Here are the
changes:

1.19 (2008/10/22)

     *   (ms) Applied patch by Peter Rabbitson, which fixes the
         caller() level when calling get_logger() on a subclass
         of Log4perl.

     *   (ms) Added documentation on is_xxx() methods and clarified
         that it doesn't necessarily mean that a message gets logged if
         they're returning true (requested by Conway Allen via
         [rt.cpan.org #39085].

     *   (ms) Applied patch by Lee Johnson to appender_by_name() to
         allow for undefined appender names without issuing a warning,
         which was occurring with Catalyst::Log4perl.

     *   (ms) Added docs on numerical levels and level strings in
         Log::Log4perl::Level.

     *   (ms) Applied patch by Anthony Foiani for support of literal
         text in DateFormat format strings.

Give it a whirl:

     http://log4perl.sourceforge.net/releases/Log-Log4perl-1.19.tar.gz

If all goes well, it'll hit CPAN in a couple of days.

Enjoy!

-- Mike

Mike Schilli
m...@pe...