Despite IBM’s best efforts, the majority of customers still use older MVS mainframes for mission critical applications.
I’m assuming you have either an s/390, or a zseries mainframe in your infrastructure and it’s no wonder. They are the most accommodating systems available on the market today. The s/309 and the zseries host a number of application and OS workloads in a variety of various application architectures.
For those among you that use the older s/370 mainframes, which by the way precede the system 390 revamp and rebranding on the early 90’s, IBM are wondering what on earth you’re waiting for.
The beauty of the zseries is that the price is at a capacity to suit almost any customer. According to Jim Porell, IBM engineer and chief architect, it makes sense to upgrade to the zseries.
“If you’d asked me this question a few years ago, I would have said that an upgrade would be beneficial, however the z/OS 1.4 really brought a tremendous number of features and enhancements, and in turn, a large number of OS/390 shops have come on board. Although we still have a few MVS customers, two years ago, it was a big problem. But it’s much less of a problem now, all thanks to the economics of zseries, and the new workload license charges—they have really reinvigorated this platform.”
Nonetheless the majority of customers still run mission critical applications and systems on the older MVS mainframes. Despite the efforts of IBM to get these customers to upgrade to zseries, the all seem to be staying put.
The MVS mainframes of the 70’s and 80’s weren’t so as accommodating as today’s zseries systems. Instead they were the products of an age where the mainframe was king. This has ramifications for customers wishing to include the older MVS mainframes in the application architectures of present.
As a result of this, SNA was still remaining the dominant mainframe architecture and TCP/IP support was a long way from ready. Many customers have upgraded, or modernized their MVS TCP/IP stacks via IBM global services. Most of the shops though, will probably require TCP/IP-to-SNA integration middleware in order to access 3270 data streams.
It’s just as well then, that IBM and other vendors offer 3270-to-XML translation so customers have no shortage of solutions from which to choose. IBM markets their HATS server (Host Access Transformation Server) which is now available in version 6.0. Host Access Transformation Server provides a drag and drop environment without directly changing the source code. This also configures applications on a screen-by-screen basis without changing the source code too.
Big Blue, position HATS as a tool for enterprise environments that are short on IT talent as well as those that are unable to spare IT resources. HATS applies presentation rules to green screens as they are found in a 3270 stream and also skip through the occasional green screens programmatically. Organisers can customise the presentation logic of host data by inserting corporate banners into the stream. This is viable because HATS re-displays 3270 data streams in a web browser interface.
Microsoft also market their own Host Integration Server (HIS) which was formerly the SNA server, which facilitates access to SNA-compatible applications and services. The BizTalk server can be used by developers in conjunction with third party solutions such as OnWeb.
At the end of the day, says Porell, if a customer seeks to expose MVS applications that run on older S/370 mainframes, then there are no shortage of vendor solutions with which to do so.
There are a whole host of vendors out there that have built servers, either at the application layer, or at the presentation layer for example, to try to provide the bond between older mainframes and that of present mainframes. If you look at the aggregation costs for these solutions along with MSV support, I think there might be a very, very interesting debate whether or not it wouldn’t be more beneficial for these customers to move on the zseries.