Chapter 1. Introduction to Legacy Modernization

A lot has been written on legacy modernization in the past few years. Most of the books, analyst reports, and white papers discuss at a high level why one should modernize and theorize, and the different approaches to, and possible outcomes of modernization. Instead of going into modernization theory, we will quickly dive into the details of two very well known modernization approaches: SOA Enablement and Re-architect. There will be a specific focus on modernization to Open Systems taking advantage of the Oracle technology stack, which can provide mainframe quality of service while delivering the agility of a modern architecture simultaneously. We will uncover a specific set of tools and show the process from end-to-end.

We will take an agnostic perspective of hardware and operating systems as most of these have proven to be capable of handling the reliability, scalability, and performance of a mainframe system. In fact, at the time of this writing, the current records for transactions per second have been delivered with Oracle on Intel-based servers.

For most organizations, the ideal solution would be to re-architect everything since re-architecting yields the most modernized environment — the environment that makes the best use of modern technology, is the most agile when it comes to change, and relies no longer on legacy skill sets.

Although such a big bang scenario is technically feasible, in reality, it is difficult and risky for any organization to accomplish this in a single re-architecting step — no matter how desirable the outcome. Most organizations would view such a big bang approach as putting their entire organization at risk. As a result, they take several intermediate steps. The following chapters show several options that could be considered in order to break down the modernization problem into byte-sized chunks — all the while delivering the final goal of achieving a process-driven SOA architecture based on J2EE. Additionally, these intermediate steps of SOA enablement will yield measurable ROI and benefit.