The implementation of Java DMK 5.1 has changed with regard to the production of tracing and debugging information:
The source code of Java DMK 5.1 now uses directly the java.util.logging API to emit debug and trace messages.
The com.sun.jdmk.TraceManager class, com.sun.jdmk.trace.* classes and com.sun.jdmk.Trace class (already deprecated in Java DMK 5.0) are all deprecated in Java DMK 5.1.
Backward compatibility with Java DMK 5.0 system properties is preserved: -DLEVEL_* and -DINFO_* flags still activate the traces.
When java.util.logging is not present, it is still possible to activate the traces by specifying -DLEVEL_DEBUG or -DLEVEL_TRACE on the Java command line.