Java.lang.outofmemoryerror: Java heap space in Maven

java

memory-management

maven-configuration

performance-optimization

byAlex Kataev·Jan 15, 2025

Eliminate the java.lang.OutOfMemoryError: Java heap space hiccup in Maven swiftly by upping the heap’s size. Configure MAVEN_OPTS for an expanded limit:

export MAVEN_OPTS="-Xmx1024m"

Alternatively, inject -Xmx directly into your build command for an impromptu heap size upgrade:

mvn clean install -DargLine="-Xmx1024m"

Opt for a heap size that harmonizes with your build requirements.

Working around surefire-plugin

Most memory griefs surface during the testing phase, courtesy of the maven-surefire-plugin. By default, this plugin chooses to fork new JVM bubbles for your tests, those unfortunately don't inherit the MAVEN_OPTS.

You need to directly configure the JVM options for maven-surefire-plugin. In your pom.xml, locate the plugin configuration section and tweak the <argLine> property:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-surefire-plugin</artifactId>
    <version>2.22.2</version> <!-- A spoon of this version helps the heap-size medicine go down -->
    <configuration>
        <argLine>-Xmx1024m -XX:MaxPermSize=256m</argLine>
    </configuration>
</plugin>

Not all problems are nail(s), stop hammering with heap size!

Increasing memory limits is akin to patching a leaky roof; sometimes, your problems are termites (inefficient tests or flawed code). Take a meticulous look at the stack trace for the test causing the memory issue- your tests would thank you for it!

The devil beyond the heap details

Ponder updating your Java Development Kit. JDK 1.7 and upward bring along efficient performance and better memory management. If your project doesn’t protest, try a fresher Maven version for potential relief.

The memory saga

Finding memory leaks and striving to optimize tests reduces memory intake. Bloatware dependencies and sizeable files that overload your build- it's time they got a detox!

Realigning environment settings, Maven profiles to the rescue

Create a Maven profile for tailored memory settings suiting different environments. No more meddling with the main build scripts:

<profiles>
  <profile>
    <id>large-memory-profile</id>
    <properties>
      <env.MAVEN_OPTS>-Xmx2048m</env.MAVEN_OPTS> <!-- Because size does matter, well, at least in Java heap size -->
    </properties>
  </profile>
</profiles>

Parallely bridging execution gaps

Explore launching your tests in parallel, it's like shooting two birds with the same amount of stones - reduced load and faster build times:

<configuration>
    <parallel>methods</parallel> <!-- multicore magic -->
    <threadCount>4</threadCount> <!-- because teamwork makes the dream work! -->
</configuration>