This post is part of a series exploring the unique aspects and capabilities of WebSphere Liberty when running on z/OS.
We'll also explore considerations when moving from WebSphere traditional on z/OS to Liberty on z/OS.
The next post in the series is here.
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It is tempting to try to answer this question by giving a history of WebSphere and going through various product names and incarnations. We’ll get to that in a later post. But first I’d like to consider it as just an independent thing, ignoring all the history.
Still, we should consider the distinction between Open Liberty and WebSphere Liberty, and then what that “on z/OS” gets us, at least at a high level. Open Liberty is the open source implementation of a Jakarta EE compliant application server (formerly Java EE, but we said no history of names..). That means it can do all sorts of things you’d need an application server to do.
What does that mean? Well, it provides standard ways to get work into the server like HTTP and message-driven applications. It also means that there are standard security mechanisms to control both who can access the server and what they can do once they have (verifying they are, indeed, who they claim, of course). It also provides transactional semantics around resource manager access, as well as standard ways to access those resources, like JDBC, etc.
Basically, if you want to write an application in Java that is driven by open standard based mechanisms and does its application-things using open standard mechanisms, then Open Liberty is a good place to do that.
Well then, what’s WebSphere Liberty? That is, mostly, the supported version of Open Liberty. You can get the source for Open Liberty if you want. Use it all you like. But if you want IBM support for it, you need to buy a license for WebSphere Liberty. I’m over-simplifying here, of course.
What about that “on z/OS” part? Java is supposed to run everywhere (more or less), so why is there some special z/OS thing? Well, the “on z/OS” is one of those ‘extra’ things available in WebSphere Liberty that isn’t in Open Liberty. It consists of some additional features and functions to integrate with and exploit z/OS capabilities.
And that’s actually what this blog is about. We’re just going to take everything that’s in Open Liberty as a given. Anything you read anywhere else about it will apply on z/OS (unless what you’re reading is specific to some other platform of course). In the following posts we’ll take a look at what is unique, special, different, and hopefully interesting about the extra z/OS stuff that makes up the “on z/OS” part of WebSphere Liberty on z/OS.
If you’re currently running WebSphere traditional on z/OS, we’ll also take a look at some things you might consider as you move to WebSphere Liberty on z/OS.
Index of all other posts in this series
Liberty z/OS Post #2- A Brief History of WebSphere Application Server
Liberty z/OS Post #3- Product Names and Open Liberty
Liberty z/OS Post #4- Why is Liberty Different on z/OS?
Liberty z/OS Post #5- Liberty Built Into z/OS
Liberty z/OS Post #6- Liberty Inside CICS
Liberty z/OS Post #7- Migrating From WAS traditional – Why and When
Liberty z/OS Post #8- Defining a Liberty on z/OS Development Environment
Liberty z/OS Post #9- Migrating Applications from WebSphere traditional to Liberty on z/OS
Liberty z/OS Post #10- Product Registration
Liberty z/OS Post #11- Running as a z/OS Started Task
Liberty z/OS Post #12- What’s in the Liberty Server JCL PROC
Liberty z/OS Post #13- All for One (PROC) and One (PROC) for All or Not
Liberty z/OS Post #14- Introduction to Liberty Diagnostics
Liberty z/OS Post #15- Where Should the Output Go
Liberty z/OS Post #16- Logs, Traces, and Dumps, Oh My
Liberty z/OS Post #17- The Madness of the MSGLOG Multiverse
Liberty z/OS Post #18- WTOs and Redirecting Messages
Liberty z/OS Post #19- Messages to Automate By
Liberty z/OS Post #20- Diagnostic Tips – Traces
Liberty z/OS Post #21- Diagnostic Tips – Dumps
Liberty z/OS Post #22- Production Topology migration
Liberty z/OS Post #23- Introduction to configuration topology decisions
Liberty z/OS Post #24- How Many Server Groupings Do You Need
Liberty z/OS Post #25- A Look At Using Include Files
Liberty z/OS Post #26- Setting Environment Variables
Liberty z/OS Post #27- Using Variables in Server Configuration
Liberty z/OS Post #28- Extracting the Server Configuration
Liberty z/OS Post #29- An Easier Way to Find a Server Configuration
Liberty z/OS Post #30- Thoughts about Liberty z/OS File Systems
Liberty z/OS Post #31- Liberty z/OS File Permissions
Liberty z/OS Post #32- Maintenance Strategies for Liberty z/OS
Liberty z/OS Post #33- Some Thoughts About Installation and Maintenance
Liberty z/OS Post #34- Automating Liberty z/OS Server Creation
Liberty z/OS Post #35- My Servers, Your Servers, Somebody Else’s Servers
Liberty z/OS Post #36- Application Installation
Liberty z/OS Post #37- Should you use the dropins folder for production servers
Liberty z/OS Post #38- What features do you need?
Liberty z/OS Post #39- An Overview of Liberty z/OS Modify Commands
Liberty z/OS Post #40- Modify Driven Configuration Update
Liberty z/OS Post #41- Displaying Liberty z/OS Work Counters
Liberty z/OS Post #42- Displaying Information About Liberty z/OS Interrupted Requests
Liberty z/OS Post #43- Dynamically Modifying Tracing from the z/OS Console
Liberty z/OS Post #44- Triggering Diagnostic Dumps of Liberty from the z/OS Console
Liberty z/OS Post #45- Auth Cache Clearing and Keystore Refresh from the z/OS Console
Liberty z/OS Post #46- Hitting Pause on Liberty z/OS
Liberty z/OS Post #47- Introducing the Liberty Angel
Liberty z/OS Post #48-How Does the Liberty Angel Work?
Liberty z/OS Post #49- Do You Need an Angel?
Liberty z/OS Post #50- Security for the Liberty Angel
Liberty z/OS Post #51- Naming Your Angel
Liberty z/OS Post #52- How Many Angels Do You Need?
Liberty z/OS Post #53- Requiring an Angel and Required Angel Services
Liberty z/OS Post #54- A Clarification on Angel and Server Code Levels
Liberty z/OS Post #55- Modify Commands for Liberty Angels
Liberty z/OS Post #56- Stopping the Angel
Liberty z/OS Post #57- WLM Integration
Liberty z/OS Post #58- Classifying Work With WLM