In 2002, I wrote an article entitled Web Services Idées Fortes — idées fortes meaning powerful ideas. The three powerful ideas: asynchrony, loose coupling, and coarse granularity.
The reason these three representative characteristics were so powerful was that integrating with Web Services represented a new way of connecting systems.
Asynchrony allowed the connected applications to run independently of one another, instead of requiring clients to wait for servers to respond. Today, asynchronous behavior is the norm, enabling high-speed enterprise integration.
Loose coupling allowed developers to make certain changes to the software at one end of an interaction without breaking the software at the other end. Loose coupling has also found its place in modern integration, for example, how microservices interact across business domains.
The Third Idée Forte
The third Idée Forte is coarse granularity. Instead of sending small amounts of information with each request, Web Services preferred to send and receive XML documents containing all manner of structured (or semi-structured) information.
Such coarse-grained interactions have two essential benefits: first, because one application can bundle up various data for either a request or response, integration requires fewer round trip interactions.
Coarse granularity thus dramatically speeds up performance in situations where there may be a limitation in bandwidth (say, when one endpoint is a smartphone), or when the overhead of the integration step itself is higher than the overhead for processing the messages (in particular, when one endpoint is a mainframe).
The second benefit to coarse-grained interactions: each message can preserve the business context far better than fine-grained interactions can. Compare, for instance, having a server send a single value vs. sending an entire invoice. The recipient application may not understand what the value is for, but is more likely to recognize an invoice.
The Power of JSON and REST
Today, XML is still in wide use, but most people consider it to be a legacy protocol, as JSON has largely replaced it. JSON is both less verbose than XML, and since a JSON message is itself valid JavaScript, processing it is both simpler and more flexible than processing a corresponding XML message – especially if the application doing the processing is itself written in JavaScript.
JSON, in fact, has enabled mainframes to become fully modern endpoints within today’s hybrid IT environments.
Companies like HostBridge have perfected mainframe integration using JavaScript, and for good reason: they retain the very same idées fortes that made Web Services so powerful.
Furthermore, asynchronous JavaScript has now matured. With the proliferation of server-side JavaScript frameworks like Node.js, asynchrony is now an expected, powerful, and simple mode for JavaScript-based interactions.
Furthermore, JavaScript – JSON in particular – has brought ubiquitous loose coupling to JavaScript-based interactions as well. A JSON message doesn’t care what field names you use or what the structure of a particular message is – the recipient of that message sees it simply as more JavaScript.
The Challenges of Mainframe Integration
Coarse granularity, in contrast, can still be a challenge – especially with mainframe integration. Take, for example, the relatively new IBM z/OS Connect Enterprise Edition product.
To IBM’s credit, they are bringing improved integration technology to CICS. The problem with z/OS Connect, however, is that it only supports fine-grained interactions with legacy programs that use binary data structures like COBOL copybooks.
Instead of leveraging the inherent processing capabilities of the mainframe to orchestrate fine-grained program artifacts on the host, z/OS Connect leaves such processing to servers external to the mainframe running bespoke customer-written code, or to integration products that run on the mainframe from vendors like HostBridge.
As a result, interactions between non-mainframe servers running, say, Node.js and legacy CICS programs, can easily bog down — as some client requests can cause an impractically large number of interactions between the Node.js server and the mainframe. Such round trips slow the customer interaction down and runs up the MIPS cost on the host as well.
Furthermore, because fine-grained interactions can lose the business context of the request, z/OS Connect would not be able to catch certain problematic interactions, for example, requests for personally identifiable information (PII) or other sensitive data.
HostBridge actually solved these problems long before IBM rolled out z/OS Connect. Because the HostBridge JavaScript Engine HB.js runs JavaScript natively on the mainframe (and under CICS), and furthermore leverages JavaScript for application integration (both with JSON as well as XML), it is able to process and assemble messages on the mainframe itself.
Thus, HostBridge leverages the remarkable processing power of the mainframe to support coarse-grained interactions that take into account the business context of the information in each interaction.
The result: no bottleneck in performance as well as the ability to apply security and compliance constraints automatically, ensuring, for example, that messages comply with all appropriate policies.
And last but not least, HB.js also supports Web Services interactions, for those companies that require the idées fortes from the last decade.
The Intellyx Take
Looking back on my Idées Fortes article from 17 years ago, I am pleased with how well its core ideas hold up, even in today’s modern, hybrid IT world.
Many things change over time, but some remain the same. The mainframe in particular has shown remarkable staying power – and furthermore, every company running a mainframe by default has a hybrid IT architecture.
Core to this story of the modern mainframe is its ability to run modern software in ways that comply with modern protocols. We are fortunate, therefore, that vendors like HostBridge continue to fight the good fight for their mainframe customers – who, after all, are the enterprises that continue to provide the horsepower for the digital era.
Copyright © Intellyx LLC. Intellyx publishes the biweekly Cortex newsletter, advises companies on their digital transformation initiatives, and helps vendors communicate their agility stories. As of the time of writing, HostBridge is a current Intellyx customer and IBM is a former Intellyx customer. None of the other organizations mentioned in this article are Intellyx customers. Intellyx retains final editorial control of this article. Image credit: Michael Fraley.
Comments
Comments are closed.