Hi Arbi,
On 10.01.2025 23:27, Arbi Sookazian wrote:
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font-family:arial,helvetica,sans-serif;}Hi,
We have multiple Spring Boot 3 WEB apps (exploded WAR files) that need to log
to separate/distinct log files on the same Tomcat 10 server. I was able to
implement this successfully on Tomcat 7, log4j2, Spring 4.x using the following
doc:https://logging.apache.org/log4j/2.3.x/manual/logsep.html and
org.apache.logging.log4j.core.selector.JndiContextSelector. I'm running into
the following exception with the log4j-web-2.23.1.jar with the Tomcat 10/spring
boot deployments:
The documentation you are referencing is for the EOL 2.3.x release. The
new documentation on integrating Log4j with a Jakarta EE server is here:
https://logging.apache.org/log4j/2.x/jakarta.html
The most important difference between your previous Java EE 6
application is that starting with Jakarta EE 9, you need to add the
`log4j-jakarta-web` artifact instead of the `log4j-web` artifact[1] for
your web applications.
To have separate logger context for each web application, you can either:
1. Embed Log4j in each application. Due to the standard delegation model
of servlet containers you'll have as many Log4j Core copies as you have
applications and each one can have a configuration file. Even if you
don't use web.xml, you can setup a separate `log4jConfiguration` context
parameter in Tomcat's context descriptor[2].
2. If you wish to have a global Log4j Core installation, you could use
my custom Log4j extensions for Tomcat ([3], this is not an ASF project).
The collection of extensions contains everything necessary for a global
installation:
* A Tomcat classloader that prefers the global `log4j-api` instead of
the one bundled with your applications.[4]
* A Tomcat-specific context selector to replace the JNDI selector[5].
Unlike the JNDI selector, the TomcatContextSelector uses the thread
context classloader, so does not require additional setup.
* (optionally) A bridge between Tomcat JULI and Log4j API, if you want
to also forward Tomcat's logs to Log4j API[6].
> I'm currently trying without a web.xml and I'm noticing only one
log4j2-spring.xml file is being loaded by the log4j2 classloader.
The support for `log4j2-spring.xml` is not provided by Log4j, but by
Spring Boot. Spring Boot is very opinionated on the naming of logging
configuration files (i.e., it does not fall back to the standard Log4j
Core initialization procedure). You could try setting the
`logging.config` Spring Boot property[7] to a different value for each
application. The Tomcat context descriptor is probably the best place to
do it.
Piotr
[1]
https://logging.apache.org/log4j/2.x/jakarta.html#log4j-jakarta-web-installation
[2]
https://tomcat.apache.org/tomcat-11.0-doc/config/context.html#Context_Parameters
[3] https://oss.copernik.eu/tomcat/3.x/
[4] https://oss.copernik.eu/tomcat/3.x/components/tomcat-log4j
[5]
https://oss.copernik.eu/tomcat/3.x/components/log4j-tomcat#TomcatContextSelector
[6] https://oss.copernik.eu/tomcat/3.x/components/tomcat-juli-to-log4j
[7]
https://docs.spring.io/spring-boot/appendix/application-properties/index.html#application-properties.core.logging.config
