Re: [log4perl-devel] log4perl causing perl process to die (fwd)

[Strahan, B. <bob...@hp...>]

Hi Mike

> Does your service open a files after it's been
> running for a while? Typically, Log::Dispatch::File(::Locked) opens the
> file only once unless 'close_after_write' is given.

We do use the 'close_after_write' option... As I mentioned, there are multi=
ple concurrent processes continually being spawned by the service, each usi=
ng log4perl to log to the same logfile.  So we figured we needed to use Fil=
e::Locked along with close_after_write to ensure each process got an exclus=
ive lock on the logfile before writing to it.

Let me know if there is a better (more efficient) way to handle multiple co=
ncurrent processes logging to the same file e.g. Would using socket appende=
rs to route log messages to single log server process which handles file i/=
o from one process be a better option?


> Which version of Windows are you running by the way? On regular XP, it
> seems to work as expected.

Windows 2003 64-bit server..  I haven't tried it on other flavors of Window=
s.


For now I have worked around the problem by inserting the open() call into =
a retry loop..
    #open $fh, "$self->{mode}$self->{filename}"
    #    or die "Cannot write to '$self->{filename}': $!";
    while (1) {
       last if open $fh, "$self->{mode}$self->{filename}" ;
    }








-----Original Message-----
From: log...@li... [mailto:log4perl-devel-b=
ou...@li...] On Behalf Of Mike Schilli
Sent: Saturday, November 03, 2007 6:32 PM
To: Mike Schilli
Cc: log...@li...
Subject: Re: [log4perl-devel] log4perl causing perl process to die (fwd)

On Fri, 2 Nov 2007, Bob Strahan wrote:

> However, it seems that if certain filesystem operations are
> performed on the logfile it can cause the logger to execute die(),
> causing my service to die, with the following error
>
> Cannot write to 'D:/Program Files (x86)/My App/logs/logfile.txt':
> Permission denied at D:\Program Files (x86)\My
> App\lib\perllibs\lib/Log/Dispatch/File.pm line 86.

Hmm, this is Log::Dispatch::File's _open_file() function complaining
that an open() failed. Does your service open a files after it's been
running for a while? Typically, Log::Dispatch::File(::Locked) opens the
file only once unless 'close_after_write' is given.

Which version of Windows are you running by the way? On regular XP, it
seems to work as expected.

-- Mike

Mike Schilli
m...@pe...

> I am using log4perl in a Win32 service that needs to run forever..  Howev=
er, I have encountered a situation where the logger call is executing a die=
() and causing my service to die...
>
>
> The service spawns multiple child processes which run concurrently but al=
l log to the same logfile.. We're using File::Locked to avoid contention.. =
 Extract from our logger config below..
>
> "log4perl.appender.myapp" =3D> "Log::Dispatch::File::Locked",
> "log4perl.appender.myapp.filename" =3D> "D:/Program Files (x86)/My App/lo=
gs/logfile.txt",
> "log4perl.appender.myapp.mode" =3D> "append",
> "log4perl.appender.myapp.close_after_write" =3D> "true",
> "log4perl.appender.myapp.permissions" =3D> "0660",
> Etc..
>
>

> I can reproduce the problem sporadically by simply opening the logfile in=
 Wordpad..
> I can reproduce it reliably by repeatedly copying the logfile using test =
script below
>
> #!perl -w
> use File::Copy ;
> while (1) {
>    copy ("D:/Program Files (x86)/My App/logs/logfile.txt", "D:/Program Fi=
les (x86)/My App/logs/logfileCOPY.txt") ;
>    print "." ;
> }
>
>
> Any suggestions on how to defend against users copying or opening the log=
file?   We should block and retry until open() suceeds, rather than die(), =
I think.
>
> Please let me know if you can help with a patch, workaround, or suggestio=
n.
>
> Regards
>
>
>
> Bob Strahan
> HP Software, R&D
>
> 703.579.1929 office | 702.967.5228 mobile | 702.579.1929 fax | bob.straha=
n...@hp...<mailto:bob...@hp...>
> 10700 Parkridge Blvd. #500 | Reston | VA 20191
>
>
> -------------------------------------------------------------------------
> This SF.net email is sponsored by: Splunk Inc.
> Still grepping through log files to find problems?  Stop.
> Now Search log events and configuration files using AJAX and a browser.
> Download your FREE copy of Splunk now >> http://get.splunk.com/
> _______________________________________________
> log4perl-devel mailing list
> log...@li...
> https://lists.sourceforge.net/lists/listinfo/log4perl-devel
>

-------------------------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc.
Still grepping through log files to find problems?  Stop.
Now Search log events and configuration files using AJAX and a browser.
Download your FREE copy of Splunk now >> http://get.splunk.com/
_______________________________________________
log4perl-devel mailing list
log...@li...
https://lists.sourceforge.net/lists/listinfo/log4perl-devel