Troubleshooting
Problem
When running a JVM on z/OS as an MVS "started task", output on STDERR (which includes all JVM informational messages and debug output) is discarded by the OS. As a result, it is impossible to use the debugging features of the JVM
Resolving The Problem
The environment variable TEMP_IBM_JAVA_FAKE_STDERR has been introduced to control redirection of STDERR output (which currently includes essentially all JVM information messages and debug output).
If TEMP_IBM_JAVA_FAKE_STDERR is set to a filename, then upon the first attempt to output to STDERR, the file will be created (with default access privileges) and all subsequent output intended for STDERR will be written to the file. If the file cannot be created, an error message is output to STDOUT, and all subsequent STDERR output will appear on STDOUT.
If TEMP_IBM_JAVA_FAKE_STDERR is set but has no value, all STDERR output will be directed to STDOUT.
This is a temporary solution to the problem of STDERR output for MVS "started tasks", and an improved mechanism is to be implemented for SR1. Note that the TEMP_IBM_JAVA_FAKE_STDERR environment variable is only currently supported on z/OS.
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Document Information
Modified date:
15 June 2018
UID
swg21238234