Logging and profiling meaning of %q{2}

Question

Hi Community,

While configuring logging options in Jira Software recent versions (7.1.9 and latest) to prepare and test migration on referenced JIRA instance, We face an unknown log4j pattern in the default log4j.properties file ship with JIRA Software (Zip packages for standalone).

Extract (line 62) of log4j.properties is :

log4j.appender.filelog.layout.ConversionPattern=%d %t %p %X{jira.username} %X{jira.request.id} %X{jira.request.assession.id} %X{jira.request.ipaddr} %X{jira.request.url} [%q{2}] %m%n

Apache log4j documentation has no reference of [%q{2}] pattern (https://logging.apache.org/log4j/2.x/manual/layouts.html#PatternLayout).\

Can one please explain that pattern or point out a web link to a reference where the meaning and the description of this pattern ?

Thank you for reading and helping me.

Markus Kokott_14swp6 · Answer

%q{2} means, you take the name of the logger (like %c does) and you truncate all package parts to the first letter except for the last 2 parts followed by the class name.

For example, foo.bar.baz.qux.MyClass becomes f.b.baz.qux.MyClass.

Sebastian_94p154 · Answer

It seems to be what you configure in log4JLogger:

logger = Logger.getLogger("MyLogger")

In this example it would add a [MyLogger] to every log

That is what I understood...

BDOU · Answer

Thank you Boris for your answer but it seems to be more like a custom pattern as nor Log4j neither SLF4j use the %q char.