[logback-user] Minimal library dependency for logback implementation of RequestLogImpl

Russell E Glaue rglaue at cait.org
Tue Jan 27 20:43:06 CET 2009

Ceki Gulcu wrote:
> Ralph Goers wrote:
>> While Geronimo can use the SLF4J api, due to its licensing Logback can
>> only be an optional component for any Apache project. So you can
>> expect that the default implementation used would be log4j.
> Hello Ralph,
> You are right. At present time the ASF considers LGPL to be in category
> C (excluded licenses).
> However, I think one could argue that as long as some Apache software,
> say Geronimo, uses logback-classic via SLF4J, without ever linking
> against logback-classic, LGPL restrictions on distribution do not apply.
> I hope to eventually present this argument to legal at apache.

I support this.

I really think the line between APL and LGPL needs to be clean.
Currently Apache just says No to LGPL.
But I am not seeing how including LGPL libraries in a distribution, which only
provides additional options, can be a problem. Especially as Ceki says Logback
code is actually implementing an interface with an APL license.

The only thing to be careful of is that if there are any derived works from the
LGPL libraries, that the code is probably contributed to the LGPL licensed work
instead of the APL licensed work.

So if I want to contribute some code to Geronimo which the code actually is a
derived work of Logback libraries, I should contribute it to Logback and then
put in a request to upgrade the Logback libraries in Geronimo so that support
exists there.

And this answer a previous question of where to commit the GBean implementation
of the Logback Jetty RequestLogImpl for Geronimo. We should contribute it to
Logback for inclusion in release X, then lobby Geronimo to support release X of


> A similar argument may apply to Tomcat embedding logback-access.
> Logback-access is deployed in Tomcat as a Valve (a Tomcat structure).
> Tomcat does not link with logback-access. In a similar vein,
> logback-access implements the Jetty RequestLog interface. Jetty does not
> link with logback-access.
> Cheers,
>> Ralph

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