What’s Legacy Now: WSDLs and Stored Procedures
July 1, 2015 Alex Woodie
Thanks to the breakneck speed that information technology is evolving, the definition of what is “legacy” in computing is constantly changing. For example, 10 years ago, organizations that were coding stored procedures into their databases and exposing mainframe business logic as WSDL-based Web services were following best practices in development. But some people are now lumping those objects into the legacy computing camp, along with old RPG and COBOL programs.
The folks at OpenLegacy aren’t interested in starting a war by labeling stored procedures and first-generation WSDL-based Web services as legacy. The software modernization vendor–which last week announced a new product called eSuite that essentially converts stored procedures and old Web services into more modern Web services–is simply responding to the computer modernization needs of its customers.
“The definition of legacy has extended to SOA architectures,” says Hans Otharsson, OpenLegacy’s COO. “Today’s ‘modern’ is tomorrow’s legacy. The people who developed these things are no longer there. It’s legacy to those customers because it’s rigid, it’s fixed, and they don’t know what to do with it and how to capitalize on it.”
When the services oriented architecture (SOA) ball got rolling in the early 2000s, IT juggernauts like IBM championed the concept as the future of computing, and made money by selling the XML-based tooling necessary to encapsulate and expose the business logic captured in IBM i, mainframe, and other hosts via Web services that could be called over the Internet.
The new eSuite product that OpenLegacy launched a week ago gives IBM i and mainframe shops a bridge to convert and expose those WSDLs and database stored procedures using modern REST-based Web services. Zeev Avidan, vice president of product management at OpenLegacy, explains how it works.
“Basically we can give them a unified platform to help them expose all their APIs,” Avidan tells IT Jungle. “We can consume the Web services as easily as we can consume screens and transactions, and expose everything as REST APIs, JSON-based protocols, or even generate entirely new Web or mobile interfaces, out of the box.”
The SOA architecture may not have been heavily adopted. But for those IBM i and mainframe shops that did heavily invest in the IBM tooling to generate WDSLs, OpenLegacy can make those Web services look like modern REST services that many programmers are familiar with.
“You’d never know . . . that this is basically the same program on the same Web service with different parameters, because we do all of this abstraction for you,” Avidan says. “So the end result for the mobile developer would be a well-structured API, which would be exactly what they’d expect from the more modern services that they’re used to.”
Customers may choose to keep the legacy services in place, and simply add the capability to call them via REST services. This would be especially applicable to stored procedures, which are still considered a best practice in application development due to the stronger data integrity assurances they can provide compared to business logic coded at the application level.
But when it comes to older WSDLs developed as part of a heavy SOA or Enterprise Service Bus (ESB) system, it may be preferable to turn the old stuff off and rely on the OpenLegacy server to broker the application interface into the IBM i and mainframe hosts.
“It’s not that we’re coming in and telling them to change their architecture and their structure and their investment in their whole SOA or ESB,” Otharsson says. “What we’re saying is we can help you extend those, and you also have the option to continue to do what you’re doing, or see if there’s a better, faster way to do it by using the OpenLegacy platform to generate new ones.”
The Israel-based company–which came out of stealth earlier this year and has made a considerable splash with its open-source business model–has several other integration irons in the fire, including the new secure Web gateway and cloud-based deployments.
OpenLegacy’s forthcoming gateway offering will function essentially as a proxy server for OpenLegacy connections. Instead of exposing the OpenLegacy server to the Internet, the gateway will sit in the demilitarized zone (DMZ) of a company’s intranet, and function as a mirror to the OpenLegacy server, which serves up connections to the backend IBM i or z/OS server.
The new cloud offering, which is ostensibly planned for release this fall, will enable the OpenLegacy server to reside in any public cloud, such as those from IBM BlueMix, Microsoft Azure, and Amazon Web Services. This offering will utilize Docker container technology to enable OpenLegacy server to scale easily up or down as capacity dictates.
This approach will give IBM i and z/OS shops some of the scalability benefits of the cloud, but without adopting the risk, OpenLegacy says. According to Avidan, the company is essentially offloading–via the use of REST APIs and some data caching–read-intensive workloads from IBM i and z/OS servers onto the OpenLegacy server running on the cloud.
“We learned we can do this quite efficiently by caching the data,” Avidan says. “It’s less true for update requests, but for reads and getting information, we can do very efficient caching, which allows us to scale the legacy system without touching the legacy system.”
More than 10 years ago, IBM articulated a vision in which monolithic applications would be broken up into smaller chunks and called as needed using Web services. This API-centric view of the world didn’t quite pan out as IBM intended, and monolithic mainframes and IBM i servers still roam the earth with their monolithic ERP suites largely intact.
But it’s interesting to see that OpenLegacy is essentially adopting this same vision, but giving it a modern REST-JSON twist and an agile flavor. IBM, of course, is also moving strongly to adopting REST and JSON technologies with the latest releases of the operating system, but it hasn’t brought all the pieces together in a single offering. The fact that OpenLegacy has apparently figured out a way to get IBM i workloads running on BlueMix, via Docker, is also quite interesting. That’s been something that IBM itself so far has been unwilling, or unable, to tackle.