System z Development Made Easy
timhahn 100000F0AC Comments (16) Visits (12135)
I often hear from people I work with that “System z is old school” or “no one writes code for mainframes any more.” I quietly let them say their piece – but I know better. There is plenty of new and exciting work being done with every hardware platform that IBM offers – System z included. But I'm getting ahead of myself. In this blog post, I'll look at mainframe application development, de-bunk some common misconceptions, and provide links to the latest technology for streamlining application development on z/OS and Linux for System z.
Current Thinking on Developing applications for Mainframe Systems
Except for the savvy group of "Master the Mainframe" students from universities, if you ask someone in a Computer Science program about how much exposure to mainframes and z/OS they receive you'll find that they give you something of a hollow stare. “Mainframes? Nobody writes applications for them any more.” some of them might (erroneously) say. And even if you ask someone who knows that there is quite a bit of new work done on mainframe systems every day, they usually think of some archaic programming environment involving large, heavy, and old text-based terminals with 24x80 screens.
There's an ongoing perception that application development for z/OS requires the use of text-based user interfaces , writing code in assembler language, using ALL CAPITAL LETTERS, and lacking common comforts such as interactive debuggers. This causes most people to think that writing applications for z/OS is hard to do and thus they tend to avoid it whenever possible. This, in turn, feeds the urban legend of the difficulty in working with z/OS, since the set of people working with the systems becomes more isolated. While this ancient history is fun to think about, it turns out that the reality of developing applications for z/OS is very much different than this urban legend.
To further the thinking, people also believe that accessing mainframe systems is nigh impossible to accomplish. Here is a point that has a level of truth in it. It is true that mainframe systems don't grow on trees, or fit in our pockets. And so it has been a bit of a struggle in the past to get access to mainframe systems. But recent offerings are making this barrier to entry come down – I'll give some pointers on this at the end of this blog post.
It turns out that as of 2012, the common perceptions about application development for z/OS are very far from reality. The reality here is that application development for z/OS is very much like application development for any other platform. You use modern application development tools including integrated development environments (IDEs), interactive debuggers, feature-rich, syntax-highlighting editors, including wizards which generate application source code on your behalf. These tools also include capabilities to interact with remote databases, allowing teams to test out complex SQL queries prior to coding them into applications and support for multiple programming languages including Java, C/C++, COBOL, and PL/I. The tools assist development teams in compiling, linking, and debugging their applications, all from a remotely connected workstation which communicates with the application running on the mainframe system.
COBOL is a very common language used for business applications running on mainframe systems. The tools available for COBOL are vast and deep in function, ranging from code analysis and understanding tools to advanced code re-factoring support built into the code editors. This re-factoring support allows for re-locating blocks of function, ensuring that the resulting application code still performs the same set of steps after the re-factoring is complete.
In addition to COBOL, however, Java is a very popular programming language for mainframe applications. Java applications running in application server environments, on-line transaction processing environments, as well as for running batch programs are all supported, with the tools helping teams write these applications and deploy them into the target runtime environments.
This still leaves the access to the z/OS systems as something to take care of. Well, it turns out that there is a solution to this issue as well. It is now possible to access a high fidelity emulation environment for application development of mainframe applications – whether those are COBOL, C/C++, Java, or even assembler language programs. And for all the runtime environments into which those applications might run – batch, WebSphere Application Server, CICS, IMS, or DB2. This environment can be thought of as an emulation environment rather than a simulation of mainframe functions running on a workstation. As such, development teams can get much more familiar with System z and z/OS systems as well as working with their applications running in their intended runtime environments.
Now to Make it Easy
All the parts which I've described above have been available separately for quite some time now. For those that are wondering what the names of those tools are, here is a quick list:
However, the burden has been on the development organization to realize the integration points amongst these tools and to figure out how to use the above tools in the combination for which they were intended.
A solution from IBM takes the guessing out of this and helps teams realize the benefits of using the above tools in combination. The Integrated Solution for System z Development (ISD for z) is a combination of the tools I have noted above. This solution represents the recommended set of tools for developing applications that contain mainframe components. The solution and the corresponding integrations have been optimized to support typical development usage scenarios. With ISD for z, you get all the capabilities which you have come to expect when writing code for Linux or Windows platforms, along with a whole lot more features to enable team collaboration across projects which have pieces that run on multiple platforms.
Application development for z/OS and System z is really just like development for every other platform. Tools exist to help access the system environment, edit, compile, and debug applications running on the platform, and even understand existing applications which have evolved over decades of continual refinement. And access to a z/OS system for application development purposes is easier than ever before – removing that barrier to entry which has held development teams back in the past.
Have a look at these and I think you'll agree that the future is bright for software development – no matter what the target platform is. In fact, the tools enable organizations to choose their deployment platform based on their business requirements, not based on the skill-set of their organization. This frees up the organization to choose the best platform for the job to be performed – freedom indeed!