Spring Boot ignoring logback-spring.xml

Question

I have 2 Spring Boot (1.4.1-RELEASE) console applications using Logback. Both configuration files are more or less identical, are located in my /src/main/resources folder and named logback-spring.xml.

Both projects include the maven dependency spring-boot-starter-logging in their pom.xml and fetch the logback Version 1.1.7.

The Spring Boot config as defined in both poms:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.4.1.RELEASE</version>
    <relativePath />
</parent>

<groupId>d.m.v.app-a</groupId>
<artifactId>my-app-a</artifactId>
<version>1.0.16-SNAPSHOT</version>
<packaging>jar</packaging>  

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-actuator</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-security</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-logging</artifactId>
    </dependency>
</dependencies>

However, when running the applications one of them seems to fully ignore the logback configuration while the other picks it up like expected.

If I change the filename to logback.xml for the application that didn't work properly it suddenly works fine (even with the spring profiles that I'm using in them).

There is no apparent difference in any of the configurations involved (meaning the pom.xml, application.properties, etc.).

Does anybody know why that might be the case? I find this behaviour rather confusing.

Answer 1

I know it is somewhat old, but i had the same issue and figured it out... so the reason is simply that you have a logback.xml on your classpath (somewhere, not necessarily in your project which you start, in my case it was a dependency).

Take a look here: org.springframework.boot.logging.AbstractLoggingSystem.initializeWithConventions(LoggingInitializationContext, LogFile)

set a breakpoint, then you will see.

If spring boot doesn't find any logback configurations ("logback-test.groovy", "logback-test.xml", "logback.groovy", "logback.xml") on the classpath, logback-spring.xml will be picked up.