Adding the agent#

Add -javaagent to the JVM that runs your code. Where it goes depends on how that JVM starts.

Where to put -javaagent#

Runner	Where	Example
Fat jar, or plain `java`	`JAVA_TOOL_OPTIONS`	`spring-batch`
Spring Boot	`JAVA_TOOL_OPTIONS`	`spring-boot-mvc`
Helidon SE	`JAVA_TOOL_OPTIONS`	`helidon-se`
Quarkus	`JAVA_TOOL_OPTIONS`	`quarkus`
Micronaut	`JAVA_TOOL_OPTIONS`	`micronaut`
Maven Surefire	`argLine`	`junit-maven`
Gradle	`tasks.test.jvmArgs`	`junit-gradle`
Tomcat	`CATALINA_OPTS`	`tomcat-war`
Jetty	`JAVA_OPTIONS`	`jetty-war`
WildFly	`JAVA_OPTS`	`wildfly-war`
Open Liberty	`jvm.options`	`open-liberty-war`

JAVA_TOOL_OPTIONS applies to every JVM started with it, build tools included. Set it only for the application.

JMX flags#

To record with JDK Mission Control, add these flags in the same place.

-Dcom.sun.management.jmxremote.port=7091
-Dcom.sun.management.jmxremote.rmi.port=7091
-Dcom.sun.management.jmxremote.authenticate=false
-Dcom.sun.management.jmxremote.ssl=false
-Djava.rmi.server.hostname=localhost

Warning

Anyone who can reach this port can control the JVM, with no password. Use these flags only on your development machine.

From a container or another host#

Container: publish the port to your machine only, as in -p 127.0.0.1:7091:7091. Keep java.rmi.server.hostname=localhost.
Another host: set java.rmi.server.hostname to the name JDK Mission Control uses for that host, and connect to <host>:7091. Use a network you trust.

JDK Mission Control connects to the port, then to the host named in java.rmi.server.hostname, so both must be reachable.