How to control VM arguments for maven-jetty-plugin?

Question

How to set VM arguments for Jetty run from maven-jetty-plugin?

For example, I need to pass -Xmx arguments to Jetty run by the mvn jetty:run

Answer 1

There is no way using the commandline. But you could copy the mvn.cmd / mvn.sh to mvnhp.cmd and change the line

%MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %CLASSWORLDS_JAR% "-Dclassworlds.conf=%M2_HOME%\bin\m2.conf" "-Dmaven.home=%M2_HOME%" "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %CLASSWORLDS_LAUNCHER% %MAVEN_CMD_LINE_ARGS%

To

%MAVEN_JAVA_EXE% -Xmx1024m %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %CLASSWORLDS_JAR% "-Dclassworlds.conf=%M2_HOME%\bin\m2.conf" "-Dmaven.home=%M2_HOME%" "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %CLASSWORLDS_LAUNCHER% %MAVEN_CMD_LINE_ARGS%

Answer 2

The plugin allows you to specify jvmArgs like this:

<plugin>
<groupId>org.mortbay.jetty</groupId>
<artifactId>jetty-maven-plugin</artifactId>
<configuration>
    <jvmArgs>-Xmx1024</jvmArgs>
    <scanIntervalSeconds>10</scanIntervalSeconds>
    <connectors>
        <connector implementation="org.eclipse.jetty.server.nio.SelectChannelConnector">
            <port>8080</port>
            <maxIdleTime>60000</maxIdleTime>
        </connector>
    </connectors>
    <webAppConfig>
        <jettyEnvXml>jetty-env.xml</jettyEnvXml>
    </webAppConfig>
</configuration>
<executions>
    <execution>
        <phase>test</phase>
        <goals>
            <goal>run-exploded</goal>
        </goals>
    </execution>
</executions>
</plugin>

Answer 3

It seems like your current approach is correct - when running jetty through maven, jetty is a thread inside the maven process. So increasing maven's heap will increase jetty's heap.

How are you setting MAVEN_OPTS?

One example I found looks like this: MAVEN_OPTS='-Xmx256m -Xms10m' mvn clean jetty:run

Note that MAVEN_OPTS is an environment variable here, and not passed to the JVM (who wouldn't know what to do with it).