Dynamic instrumentation with javaagent is broken

[lambrospetrou]

Hello,
I have been trying to use a project (presto-gateway) that uses ActiveJDBC, and due to the deployment environment we need to use the dynamic instrumentation using -javaagent. We use version 2.3 in this project.

However, the dynamic instrumentation fails with this error message:

Exception in thread "main" java.lang.reflect.InvocationTargetException
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:568)
	at java.instrument/sun.instrument.InstrumentationImpl.loadClassAndStartAgent(InstrumentationImpl.java:491)
	at java.instrument/sun.instrument.InstrumentationImpl.loadClassAndCallPremain(InstrumentationImpl.java:503)
Caused by: org.javalite.instrumentation.InstrumentationException: java.lang.NoSuchMethodException: org.javalite.activejdbc.ModelFinder.modelFound(java.lang.String)
	at org.javalite.instrumentation.JavaAgent.premain(JavaAgent.java:59)
	... 6 more
Caused by: java.lang.NoSuchMethodException: org.javalite.activejdbc.ModelFinder.modelFound(java.lang.String)
	at java.base/java.lang.Class.getDeclaredMethod(Class.java:2675)
	at org.javalite.instrumentation.JavaAgent.premain(JavaAgent.java:57)
	... 6 more
*** java.lang.instrument ASSERTION FAILED ***: "result" with message agent load/premain call failed at src/java.instrument/share/native/libinstrument/JPLISAgent.c line: 42

I have traced that the instrumentation library attempts to load a ModelFinder::modelFound method (see code), but that method is commented out in that class (see code).

Is dynamic instrumentation not working properly, or is there a different way to enable that?

The README does not provide any indication on this issue.

[ipolevoy]

@yanchevsky looks like you commented out these lines. Do you remember what was the reason?

[ipolevoy]

Additional investigation:

The example: activejdbc-simple from the examples project fails with the same exception using these commands:

mvn clean package -DskipTests=true
mvn dependency:unpack-dependencies
java -javaagent:/home/igor/.m2/repository/org/javalite/activejdbc-instrumentation/3.0/activejdbc-instrumentation-3.0.jar  -classpath target/dependency:target/classes activejdbc.examples.simple.Main

java -javaagent:/home/igor/.m2/repository/org/javalite/activejdbc-instrumentation/3.0/activejdbc-instrumentation-3.0.jar -classpath target/dependency:target/classes activejdbc.examples.simple.Main