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Mustgather: Setup for diagnosing Java VerifyError on AIX® , Linux, Windows and z/OS®

Troubleshooting


Problem

If your Java application experiences a Java VerifyError on any one of the operating systems such as AIX® , Linux, Windows and z/OS® , there are a number of diagnostic data files that are useful for diagnosing the problem. This mustgather document describes about the required settings to be in place in order to generate those diagnostic data files.

Resolving The Problem

In order to collect the diagnostic data files required for diagnosing the VerifyError, check that the following specific settings are configured before running your application:

1. Enable javacore generation
2. Enable core dump generation
3. Enable snap trace generation

Please note that the javacore, core dump and snap trace generation can be enabled using the below single -Xdump option:


-Xdump:java+snap+system:events=throw+systhrow,filter=java/lang/VerifyError,range=1..2

Note that the above option will limit the number of dumps produced on VerifyError conditions to a maximum of 2.

NOTE: From Java 8 releases, 'msg_filter' option can be used as a filter on text string within an exception message, to reduce the number of dump files generated. This option is supported only for the following events: throw, catch, systhrow, and uncaught.

For example,
-Xdump:java+snap+system:events=throw+systhrow,filter=java/lang/VerifyError,range=1..2,msg_filter=*class format*

4. Enable verbose output on classloading using the below JVM option:
-verbose:dynload

Note that the output will be directed to the standard error log.

[{"Product":{"code":"SSNVBF","label":"Runtimes for Java Technology"},"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Component":"General","Platform":[{"code":"PF002","label":"AIX"},{"code":"PF016","label":"Linux"},{"code":"PF033","label":"Windows"},{"code":"PF035","label":"z\/OS"}],"Version":"8.0;7.1;7.0;6.1;6.0;5.0","Edition":"J2SE","Line of Business":{"code":"LOB36","label":"IBM Automation"}}]

Document Information

Modified date:
15 June 2018

UID

swg21676297