Debugging environment variable in DataStage

These environment variables are concerned with the debugging of DataStage® parallel jobs.

APT_DEBUG_MODULE_NAMES environment variable in DataStage

The APT_DEBUG_MODULE_NAMES environment variable specifies a list of module names for the modules to debug.

The list of module names is separated by white space. For each module name in the list, the internal IF_DEBUG statements in the module are run. The subproc operator module, which has the module name "subproc", is one example of a module that uses this facility.

APT_DEBUG_SUBPROC environment variable in DataStage

Displays debug information about each subprocess operator.

APT_EXECUTION_MODE environment variable in DataStage

Set the APT_EXECUTION_MODE environment variable to run an application in sequential execution mode.

By default, the execution mode is parallel, with multiple processes. Set APT_EXECUTION_MODE to one of the following values to run an application in sequential execution mode:

  • ONE_PROCESS one-process mode
  • MANY_PROCESS many-process mode
  • NO_SERIALIZE many-process mode, without serialization

In ONE_PROCESS mode:

  • The application runs in a single UNIX process. You need run only a single debugger session and can set breakpoints anywhere in your code.
  • Data is partitioned according to the number of nodes defined in the configuration file.
  • Each operator is run as a subroutine and is called the number of times appropriate for the number of partitions on which it must operate.

In MANY_PROCESS mode, the framework forks a new process for each instance of each operator and waits for it to complete rather than calling operators as subroutines.

In both cases, the step is run entirely on the Conductor node rather than spread across the configuration.

NO_SERIALIZE mode is similar to MANY_PROCESS mode, but the DataStage persistence mechanism is not used to load and save objects. Turning off persistence might be useful for tracking errors in derived C++ classes.

APT_NO_PM_SIGNAL_HANDLERS environment variable in DataStage

Set the APT_NO_PM_SIGNAL_HANDLERS environment variable to generate cores on Unix for use in debugging.

APT_PM_SHOW_PIDS environment variable in DataStage

If the APT_PM_SHOW_PIDS environment variable is set, players output an informational message upon startup, displaying their process ID.

APT_SHOW_LIBLOAD environment variable in DataStage

If the APT_SHOW_LIBLOAD environment variable is set, a message is written to the stdout file every time a library is loaded.

These messages can be useful for verifying that the right library is loaded.
Note: The message is output to stdout, not to the error log.

APT_CATCH_SIGSEGV environment variable in DataStage

APT_CATCH_SIGSEGV enables running job through catchsegv tool. Its default value is False. This variable has a Boolean type.

APT_DEBUG_METRICS_MESSAGES environment variable in DataStage

APT_DEBUG_METRICS_MESSAGES enables logging job metrics messages to the job log. Its default value is False. This variable has a Boolean type.

APT_DEBUG_S3 environment variable in DataStage

When APT_DEBUG_S3 is defined, it will print messages related to writing and reading from S3. Its default value is False. This variable has a Boolean type.

APT_DEBUG_TSORT_SCRATCH_SIZE environment variable in DataStage

When APT_DEBUG_TSORT_SCRATCH_SIZE is defined, it will print scratch file size before and after compression to understand how much enabling compression helped. Its default value is False. This variable has a Boolean type.

APT_ELT_PUSHDOWN_LOG_LEVEL environment variable in DataStage

APT_ELT_PUSHDOWN_LOG_LEVEL allows enabling additional debug logging from dbt for ELT pushdown jobs. This variable has a List type.

APT_PM_DUMP_SCHEMAS environment variable in DataStage

If APT_PM_DUMP_SCHEMAS set, the Parallel job will produce a report showing the schemas of each dataset in the job. Its default value is False. This variable has a Boolean type.