It is common for software developers to set job message logging to "LOG(4 00 *SECLVL) LOGCLPGM(*YES)" when troubleshooting or debugging application software issues. Some software vendors may have all of their jobs running with message logging of "LOG(0 00 *NOLIST) LOGCLPGM(*NO)". Job message logging can be changed for any active job on the system using the "Change Job (CHGJOB)" command. Most applications have their default job message logging set via a "Job Description" object. The "Change Job Description (CHGJOBD)" command can be used to modify the default settings once the correct job description is identified. The "DSPJOB OPTION(*DFNA)" command can be used on any active job to determine which job description needs to be changed.

Some of the most commonly used job message logging settings are as follows:

1) LOG(4 00 *SECLVL) LOGCLPGM(*YES)

Always generate a joblog, regardless of whether the job completes normally or ends abnormally. Always log all CL commands into the generated joblog.

2) LOG(0 00 *NOLIST) LOGCLPGM(*NO)

Never generate a joblog. Never log CL commands. When attempting to access a joblog with these settings, "No job log information." will be displayed. You can manually change the message logging for this active job using the "CHGJOB" command and the joblog will become accessible.

3) LOG(4 00 *NOLIST) LOGCLPGM(*NO)

Only generate a joblog if the job ends abnormally. CL commands are not logged into the generated joblog. All jobs that complete normally do not generate a joblog spooled file.

These are good settings for most stable Production applications. If a job does end abnormally, you do get a joblog to troubleshoot with. For those batch jobs that run thousands of times per day, you are not wasting system resources to generate unnecessary spooled files for each occurrence of the job. If you find that you have millions of pages of joblogs on your system per day, you might want to consider changing your job descriptions to these settings. It is not uncommon to see more system resources consumed by the generation of joblogs than by the actual processing performed by these jobs.