Google App Engine + Java Agent

Question

I have a .jar file with javaagent in it and I want to attach that java agent to an application running in Google App Engine cloud. I've already tried to "attach" during the deploy by:

appcfg.sh update path/to/war -javaagent:/path/to/agent.jar and 
appcfg.sh update path/to/war --jvm_flag=-javaagent:/path/to/agent.jar

Application is deployed succesfully, but there are no sings if agent is working or not.

Also I've tried to build application with Maven GWT plugin and specifing agent in build file:

<configuration>
   <disableUpdateCheck>true</disableUpdateCheck>
   <javaAgent>/path/to/plumbr.jar</javaAgent>
   <jvmFlags>
      <jvmFlag>-javaagent:/path/to/agent.jar</jvmFlag>
   </jvmFlags>
</configuration>

But still no luck.

Answer 1

The simplest cause: According to the documentation you can only use classes from the App Engine JRE White List. Since java.lang.instrument is not there then you can't use it and create javaagent.