Additional class loader diagnostics

 

+

Search Tips   |   Advanced Search

 

JVM V5.0 provides some additional options that can be useful when troubleshooting class loading problems. These options are set as command line arguments for the JVM. Select...

Servers | Application Servers | servername | Java and process management | Process Definition | Java Virtual Machine

Enter the options below in the Generic JVM arguments field:

 

-verbose:dynload

This option provides detailed information about classes being loaded. Information includes the class name and package, the JAR file name if the class is packaged in a JAR file, the size of the class, and the time it takes to load the class. The information is written to the native_stderr.log file. An example output looks like:

<Loaded com/itso/classloaders/VersionChecker>
< Class size 817; ROM size 728; debug size 0>
< Read time 0 usec; Load time 40 usec; Translate time 89 usec>

 

-Dibm.cl.verbose=<name>

This option allows you to trace the way the class loaders find and load a given class. The name is the full name of the class, including the package name.

For example, by specifying...

-Dibm.cl.verbose=com.itso.classloaders.VersionChecker

...the following output is printed to the SystemOut.log file when the VersionChecker class is loaded...

[8/4/06 10:29:48:639 EDT] 00000024 SystemOut O ExtClassLoader attempting to find com.itso.classloaders.VersionChecker
[8/4/06 10:29:48:639 EDT] 00000024 SystemOut O ExtClassLoader using classpath /WAS/java/jre/lib/ext/CmpCrmf.jar; /WAS/java/jre/lib/ext/whichclassloader2.jar; /WAS/java/jre/lib/ext/whichclassloader3.jar
[8/4/06 10:29:48:639 EDT] 00000024 SystemOut O ExtClassLoader could not find com/itso/classloaders/VersionChecker.class in /WAS/java/jre/lib/ext/CmpCrmf.jar
[8/4/06 10:29:48:639 EDT] 00000024 SystemOut O ExtClassLoader could not find com.itso.classloaders.VersionChecker
[8/4/06 10:29:48:639 EDT] 00000024 SystemOut O AppClassLoader attempting to find com.itso.classloaders.VersionChecker
[8/4/06 10:29:48:639 EDT] 00000024 SystemOut O AppClassLoader using classpath /WAS/profiles/AppSrv02/properties;
[8/4/06 10:29:48:649 EDT] 00000024 SystemOut O AppClassLoader could not find com/itso/classloaders/VersionChecker.class in /WAS/profiles/AppSrv02/properties
...
[8/4/06 10:29:48:649 EDT] 00000024 SystemOut O AppClassLoader could not find com.itso.classloaders.VersionChecker
[8/4/06 10:29:48:649 EDT] 00000024 SystemOut O com.ibm.ws.bootstrap.ExtClassLoader attempting to find com.itso.classloaders.VersionChecker
[8/4/06 10:29:48:649 EDT] 00000024 SystemOut O com.ibm.ws.bootstrap.ExtClassLoader using classpath /WAS/java/lib; com.ibm.ws.bootstrap.ExtClassLoader could not find com/itso/classloaders/VersionChecker.class in /WAS/java/lib

Next