IBM-wise, I’m a switch hitter. I’ve worked on both IBM i and IBM z/OS (as well as IBM z/VM, but that’s another story).
IBM i and z/OS have identical missions of reliable, unimpeachable data center operations. The two differ in focus, which I depict here using broad generalizations:
- IBM i is especially well suited to database and ERP operations with small staff benefiting from a consistent system design and a neatly prescribed programming model.
- IBM z/OS is there for honking, humongous, storage-array-cabinets-filling-a-refrigerated-warehouse-big data, and the fastest transaction processing system on the planet.
Yet otherwise they are similar:
- offering a secondary Unix-like environment largely populated by open source offerings from the GNU/Linux/BSD continuum
- loaded with decades-old mission-critical applications
Over the course of three decades in the IBM community I have been amazed by what appear as silos erected to enclose and isolate the IBM z and IBM i platforms from one another.
We are all in the same boat, we are all providing value, continuity, and reliability to the enterprise, we all confront the challenges of modernization and the need to onboard a new generation of developers and operators. Our struggles are nearly identical, yet there seems to be little awareness of the commonality between the two platforms. Practitioners sometimes focus on the differences more than on the similarities.
An interesting technical divergence between i and z occurred early on when IBM i moved towards TCP/IP-based remote management before IBM z/OS did, implementing the host server threads before HTTP became ubiquitous. IBM i web tooling traditionally was written in Java using the JTOpen toolkit to access these host servers.
Modern IBM z/OS, on the other hand, deploys REST APIs as z/OSMF (z/OS Mangement Facility) which underlies z/OS’s own navigator and other applications.
I’m blogging right now while attending a Zowe ZAC Leadership Committee online meeting. Zowe (pronounced “ZOE-wee”) is a Linux Foundation / Open Mainframe Project open source offering built on the z/OS REST API metaphor. Zowe provides a wide range of tooling which includes, for example, the Zowe VSCode extension for IBM z/OS (like the Halcyon Code for i extension) and the Zowe CLI.
So while the respective modernization efforts resemble each other at the user level, there are some quite distinct and interesting architectural differences which both communities would benefit from understanding and comparing.
Beyond that, we should also extend ourselves to support, enhance, and praise one another’s efforts.
I’ll be at IBM TechXchange Sept. 11-14 which this year is co-located with the Open Mainframe Summit. I look forward to meeting these creative pioneers who, like so many in our IBM i community, do justice to the notion that our favored platforms are moving forward with the times and with the needs of the enterprise.