https://community.dynatrace.com/t5/Open-Q-A/Is-it-possible-to-instrumenting-Java-on-the-fly/m-p/113264#M8796 <P>Oracle Java supports 2 ways of instrumenting JVM processes:</P><P>- via CLI specifying -javaagent:jarpath,</P><P>- starting agents after the JVM startup.</P><P>Which method does OneAgent use and why?</P><P>Why is it not possible to do Java code injection on the fly without java process restart?</P><P>See details:</P><P><A href="https://docs.oracle.com/javase/7/docs/api/java/lang/instrument/package-summary.html">https://docs.oracle.com/javase/7/docs/api/java/lang/instrument/package-summary.html</A></P> Wed, 03 Jun 2020 09:00:50 GMT grechnev 2020-06-03T09:00:50Z https://community.dynatrace.com/t5/Open-Q-A/Is-it-possible-to-instrumenting-Java-on-the-fly/m-p/113264#M8796 <P>Oracle Java supports 2 ways of instrumenting JVM processes:</P><P>- via CLI specifying -javaagent:jarpath,</P><P>- starting agents after the JVM startup.</P><P>Which method does OneAgent use and why?</P><P>Why is it not possible to do Java code injection on the fly without java process restart?</P><P>See details:</P><P><A href="https://docs.oracle.com/javase/7/docs/api/java/lang/instrument/package-summary.html">https://docs.oracle.com/javase/7/docs/api/java/lang/instrument/package-summary.html</A></P> Wed, 03 Jun 2020 09:00:50 GMT https://community.dynatrace.com/t5/Open-Q-A/Is-it-possible-to-instrumenting-Java-on-the-fly/m-p/113264#M8796 grechnev 2020-06-03T09:00:50Z https://community.dynatrace.com/t5/Open-Q-A/Is-it-possible-to-instrumenting-Java-on-the-fly/m-p/113265#M8797 <P>AFAIK OneAgent uses JVMTI to instrument the JVM itself. But there is also a native part of oneagent (library written in C++) linked to your JVM process. I don't think you can add any library with such functionality on the fly to any process.</P> Wed, 03 Jun 2020 13:09:45 GMT https://community.dynatrace.com/t5/Open-Q-A/Is-it-possible-to-instrumenting-Java-on-the-fly/m-p/113265#M8797 Julius_Loman 2020-06-03T13:09:45Z