Running Spring Boot "context loads" test in maven causes OutOfMemoryError

Question

I have a multi-module Maven project with two modules being Spring Boot applications. Each of them has a simple test that the Spring application context loads successfully (my tests are very similar to this one). I run this tests with the following command in project root:

mvn -P IntegrationTests clean test

During context initialization things go out of my control, the application "eats" memory (heap size grows quickly to 4 gigabytes) and then the context fails to start with java.lang.OutOfMemoryError: PermGen space error (yes, I run it in Java 7).

Monitoring task manager during testing I noticed that maven spawns two new processes that have something to do with surefire plugin. I have no idea where it comes from, because I don't add the surefire plugin in my pom.xml.

Previously when encountered the same error somewhere I specified VM options (-Xmx256m -Xms128m -XX:MaxPermSize=256m -XX:PermSize=128m for example) and the problem was solved.

This time I tried to

1. set MAVEN_OPTS environment variable
2. set VM options (when running mvn test in IntelliJ IDEA) - it affected main java process but not its children
3. add -Drun.jvmArguments="..." in command line

but the problem persists.

Please help me to fight the OutOfMemoryError in tests.

Answer 1

Add Surefire plugin explicitly to module-specific pom.xml and configure VM options there. I like this solution because this way VM options are

• passed to the spawned surefire processes (which should solve your problem)
• affect only test application builds
• shared between developers in your team
• configurable independently for every module

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-surefire-plugin</artifactId>
            <configuration>
                <argLine>-Xmx256m -Xms128m -XX:MaxPermSize=256m -XX:PermSize=128m</argLine>
            </configuration>
        </plugin>

        <!-- your other plugins go here -->
    </plugins>
</build>