Legacy at the heart of SOA
As I mentioned in a recent article '
The mainframe is the answer to all your problems' IBM is going to make a series of software announcements that will bring z/series to the heart of SOA. The first announcement included CICS Transaction Server V3.1 and CICS Transaction Gateway V6.0. They include several significant enhancements that show that IBM intends that CICS will not just be a passive legacy system but will be driving new applications and users into the web services world.
The previous release of CICS TS had support for SOAP but only as a service provider. This meant that new web services applications could request services from existing CICS applications; this wrapping of CICS gave the impression that IBM expected all new applications to be non-CICS web services solutions and that the CICS applications would, over time, be phased out and replaced by modern solutions. However the client experience of CICS SOAP was very positive; it was easy to implement and reliable. So much so that many customers implemented it without any assistance from IBM and therefore without IBM being aware of this use. These customers then came to IBM to say that they needed more function and in particular the ability to develop CICS applications that were requesters of web services. Most of these applications were modifications of existing systems but some were new solutions. Developing an application that is a requester is an indication that there are no plans to phase the application out. This means that CICS users see a long term future for CICS on the mainframe and IBM has extended the functions on that basis. The new versions have a variety of improvements but the most important are:
Support of CICS as a service requester with full support for WSDL and SOAP.
Enhancements to the interface for CICS as a service provider.
Removal of the 32K limit on messages between services. This also applies to the size of the COMMAREA used to communicate between CICS transactions.
Improved support for C and C+ giving better performance.
Improved documentation and training for new users, an essential feature for new footprints as well as for the long term viability of existing systems.
Provision of all system management through a browser interface, rather than TSO, this provides a more effective interface for the operations department and also better integrate CICS system management with other operations functions.
Enhanced security using standard SSL facilities.
As an addition to this portfolio of products, IBM also announced CICS Batch Application Control for z/OS V1.1, allowing easier management of batch processes that must co-exist and share resources with one or more CICS online transaction systems. It simplifies tasks of operators and system programmers, reducing the time required for batch processing and moving CICS applications closer to a 24x7 operation.
CICS recently celebrated its 35th anniversary. Back in the late 1970s CICS looked like an exciting area for new blood to enter, with lots of expansion and an assured future. It would seem that this is still true in the early 2000s; I would recommend that new recruits look seriously at CICS as a career path as it is still providing excitement, growth and an assured future. The lessons that can be learnt in helping support a large legacy solution are also relevant to the development and implementation of allegedly trendy new environments. Most of the problems of reliability, scalability, manageability, security and performance that will be faced by distributed solutions have already been faced by the mainframe and resolved.
