Guru: IBM i Job Log Detective Brings Structure To Job Log Analysis In VS Code

March 9, 2026 Gregory Simmons

Remain Software has released a new Visual Studio Code extension called IBM i Job Log Detective, and it targets a pain point every IBM i developer understands: reading job logs efficiently.

In addition to its marketplace availability, IBM i Job Log Detective is open source under the MIT license and can be found on GitHub at: https://github.com/RemainSoftware/jld

There has never been anything wrong with IBM i job logs themselves. They are exhaustive, consistent, and remarkably detailed. When something fails, the job log contains the truth. The issue has always been consumption. Large QPJOBLOG files can run thousands of lines (or pages), and finding the one escape or diagnostic message that actually matters often means scrolling through page after page of completion messages, command echoes, and informational chatter.

IBM i Job Log Detective changes how job logs are navigated inside Visual Studio Code. The extension automatically detects job log files by filename or recognizable content patterns, such as IBM i product identifiers like 5770SS1 or version strings in V7R6M0 format. If automatic detection does not trigger, the user can manually designate a file as a job log through the Command Palette (Ctrl+Shift+P / Cmd+Shift+P).

Once activated, the extension builds an analysis layer on top of the raw text. It introduces a dedicated Job Log Detective panel that organizes messages into a structured tree view, and it integrates with the VS Code Outline view to group messages by type and message ID. I found this very cool!

Clicking on a message jumps directly to its location in the file. Hovering over entries reveals additional details, including cause and recovery information. High-severity messages are highlighted automatically, with a default threshold of 30 that can be adjusted. There is also an option to show only high-severity messages, allowing developers to focus immediately on likely failure points. Command messages are hidden by default, which meaningfully reduces noise during troubleshooting.

The extension recognizes the full range of IBM i message types, including Escape, Diagnostic, Information, Completion, Command, Inquiry, Reply, Notify, and others. Escape and Diagnostic messages naturally receive priority during analysis. In practical terms, this means the developer can move quickly from “the job failed” to “here is the specific message that caused termination,” without manually scanning every line.

Have a look at all of the “bling” it adds to your job log:

IBM i Job Log Detective works alongside Remain’s Octo product for handling spooled files, including job logs, enabling analysis directly from those spooled outputs within VS Code. It also works with the existing Code for IBM i Spooled Files extension authored by Matt Tyler, which is already available in the marketplace. That compatibility ensures developers are not forced into a single toolchain. Instead, the extension layers structured analysis on top of spooled file workflows many teams are already using.

Multi-language support is another noteworthy feature. The extension automatically detects and parses job logs in English, German, Dutch, French, and Spanish, mapping localized message type names back to standardized categories so filtering and prioritization behave consistently. The parsing framework is extensible, allowing additional languages to be defined through localization mappings. For organizations running IBM i in non-English environments, this is more than a convenience feature; it is a practical requirement.

The broader significance of IBM i Job Log Detective lies in workflow integration. Modern IBM i development frequently involves layered architectures: web services calling APIs, APIs invoking service programs, and service programs executing embedded SQL. When failures occur several layers deep, rapid diagnosis becomes critical. The job log already contains the necessary information, but time-to-diagnosis depends heavily on how quickly that information can be isolated and understood.

By introducing structured navigation, severity-based highlighting, filtering, and tight integration with VS Code and existing spooled file tooling, IBM i Job Log Detective reduces the friction between failure and understanding. It does not replace traditional tools like WRKJOB or DSPJOBLOG, nor does it attempt to redefine IBM i diagnostics. Instead, it modernizes how developers interact with one of the platform’s most important artifacts.

IBM i has never lacked for diagnostic depth. What has sometimes lagged is the efficiency of consuming that depth within contemporary development environments. With Job Log Detective, Remain Software is addressing that gap directly, making job logs less about scrolling and more about solving.

Until next time, happy coding.

Gregory Simmons is a Project Manager with PC Richard & Son. He started on the IBM i platform in 1994, graduated with a degree in Computer Information Systems in 1997 and has been working on the OS/400 and IBM i platform ever since. He has been a registered instructor with the IBM Academic Initiative since 2007, an IBM Champion and holds a COMMON Application Developer certification. When he’s not trying to figure out how to speed up legacy programs, he enjoys speaking at technical conferences, running, backpacking, hunting, and fishing.

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