Re: [log4perl-devel] Date format discrepancy

[Roger P. <rog...@ea...>]

Kevin Goess wrote:

>>>In Log4perl the default date format is "YYYY/MM/DD HH:mm::ss". In
>>>log4j it seems to be "YYYY-MM-dd HH:mm:ss,SSS" (ISO8601) Why not use
>>>the same default format as log4j? At least a comment about this in the
>>>docs would be nice.
>>>      
>>>
>>Problem with ",SSS" is that it's a standard Java feature but it's only
>>available in Perl if  Time::HiRes is installed. Regarding slashes vs.
>>dashes, I'm flexible, though. Only drawback is that if we change it,
>>some people's log files will change which might cause some headache for
>>post processors they might have in place. Votes?
>>    
>>
>
>I'm all for conformity, but 
>
>1) can someone point me to where log4j defines that as the default?  I
>can't find it.  We do match their ISO8601 behavior with "%d{ISO8601}".
>
http://jakarta.apache.org/log4j/docs/manual.html Search for "ISO 8601 
format" and you will find a sample with the d% option. I'm not 
suggesting that the manual is any authority in this matter though :-) . 
Haven't actually tested it in log4j.

Personally I will use %d{yyyy-MM-dd HH:mm:ss} so I don't care much. 
However the log4perl docs claims that the standard formats are much 
faster (less string processing?).

>  
>
>2) the java SimpleDateFormat
>(http://java.sun.com/j2se/1.3/docs/api/java/text/SimpleDateFormat.html)
>defines "y" but not "Y".  Both log4perl and log4j seem to go back and
>forth between YYYY and yyyy, what's up with that, are they really
>interchangeable?
>
YYYY doesn't work in log4perl. The pod should be updated.

>
>3) if that is the log4j default, we could add the ,SSS if Time::HiRes is
>installed.
>
>4) if we do change, should note it prominently somewhere I guess
>
Even if it isn't changed, a note about the difference would be nice.

In 
http://log4perl.sourceforge.net/releases/Log-Log4perl/docs/html/Log/Log4perl/Layout/PatternLayout.html 
under "description"

 >The new() method creates a new PatternLayout, specifying its log 
format. The format string can contain a number of placeholders which 
will be replaced by the logging engine when it's time to log the message:
 >
 >    %c Category of the logging event.
 >    %C Fully qualified package (or class) name of the caller
 >    %d Current date in yyyy/MM/dd hh:mm:ss format
[snip]
 >    %x The topmost NDC (see below)
 >    %X{key} The entry 'key' of the MDC (see below)
 >    %% A literal percent (%) sign
 >
Note: In log4j, the default format  for %d is "yyyy-MM-dd HH:mm:ss,SSS" 
(ISO8601)

 >NDC and MDC are explained in Nested Diagnostic Context (NDC) in the 
Log::Log4perl manpage and Mapped Diagnostic Context (MDC) in the 
Log::Log4perl manpage.
 >
 >Quantify placeholders