Adding Java to IMS alongside COBOL could also reduce application complexity. Atruvia’s classic architecture makes it necessary to include “compensation” logic within every component to ensure that operations distributed across the various components can be rolled back to the last consistent state if an error or interruption occurs. Bringing Java code inside the IMS environment would make the extra logic superfluous, thereby reducing complexity, costs and delays.

“In terms of the application architecture, Java opens up the possibility of using a broader range of frameworks and protocols,” adds Thomas Bauer, Team Leader and IT Architect at Atruvia. “For example, RESTful web services are more natural in Java than in COBOL, and certain functions that are difficult to implement in a pure COBOL environment are available as prebuilt artifacts in Java. We wanted to cut time-to-market by deploying modern, reusable software components—and, at the same time, protect our investment in existing business logic by Java-enabling it.”

As Java was already a strategic platform at Atruvia, the organization was keen to enable greater portability of its code across both distributed and IBM zSystems platforms—whichever offered the best price-performance. This approach can also ease the transition to cloud computing. Since OpenShift runs on all platforms, Atruvia can move workloads to the cloud when that makes sense.

Plus, Java on IBM zSystems alongside COBOL would enable developers to enrich core banking functionality in a seamless, low-risk manner by replacing COBOL subroutines with Java without having to rewrite large programs. And it would be easier for software architects within the distributed environment to call core transaction services directly from IMS applications.

“In the longer term, our goal is to be more platform-independent by having Java building blocks that can run anywhere,” says Meyer. “Besides reducing architectural complexity, mixing COBOL and Java inside IMS would enable us to build new application components tightly integrated with existing components. In this way, we can gain the advantages of a modern hybrid app—namely, short time-to-market, increased flexibility and greater ease of development—without losing the performance benefit of IMS where it really counts in core banking transactions.”

Due to the pioneering collaboration between IBM and Atruvia, Java is now an established, production-ready component of the IBM zSystems toolbox. This significantly refreshes the IMS environment, preserving its traditional qualities of performance and robustness while enabling faster development using more widely available and sustainable programming skills. It also allows developers to enrich existing core banking functions in a low-risk, efficient manner.

“We see Java on IBM zSystems as a key technology in driving competitive advantage for our clients,” says Meyer. “With easier development and reuse of existing components, it enables us to deliver new functionality at higher speed and lower cost, supporting our banking clients as they seek to bring new services to market more rapidly.”

In fact, Atruvia has already Java-enabled around 85% of its core banking IMS transactions — some 400 million Java transactions per day with peak throughput reaching 12,000 transactions per second. Twelve IMS systems with approximately 200 million instructions per processor second (MIPS) support these business-critical transactions.

By reducing the complexity of the application environment, Java within IMS has increased the efficiency and performance of end-to-end business transactions. Before, enterprise batch processing was handled by a spread of multiple platforms. Now, all processing, regardless of the language, can simply be integrated into a single batch step by combining COBOL and Java.

Additionally, Atruvia developers can easily port Java code across its distributed and IBM zSystems environments, whichever platform offers the best price-performance. For example, Atruvia has reduced latency by colocating some distributed Java workloads to the IBM zSystems platform. “After all, the best I/O is no I/O,” quips Meyer. He reports threefold performance gains from colocation of some data-intensive apps instead of running them across the network. Clearly, a wholesale migration to the cloud is not the only path to application modernization.

In addition, there are financial incentives to move Java workloads from general processors (GPs) to IBM Z Integrated Information Processors (zIIPs), on which the licensing fees are lower. Although the MIPS required increase—because Java consumes more resources than COBOL—the overall costs are reduced.

Other efficiencies come from rich Java libraries that let programmers avoid writing custom code for common functions such as compressing and decompressing data. Similarly, Atruvia can integrate third-party Java software into its IBM zSystems environment, potentially avoiding in-house development altogether. And as new hardware-based cryptographic, compression or networking features become available on the platform, Java for IBM zSystems will give applications transparent access to the new capabilities.

“As a provider of core banking systems to more than 800 banks with tens of millions of end users, we cannot afford to compromise on performance and reliability, nor can we afford to introduce risk in our development practices,” says Meyer. “The IBM zSystems platform running IMS remains our strategic choice because it is the most secure and reliable platform that we know of, and because it offers exceptional performance for our core banking systems. With Java in IMS, we have the best of both worlds.”

Formed by the 2015 merger of Fudicia IT AG and GAD eG, Atruvia (link resides outside of ibm.com) is the digitization partner of Germany’s 820 cooperative banks. Its banking IT solutions and services range from data center operation and the agree21 banking-as-a-service process to app development and support. With administrative headquarters in Karlsruhe and Münster and branches in Munich, Frankfurt and Berlin, Atruvia employs almost 8,400 people and reported group sales of around EUR 1.77 billion in 2020.