Gralla on Mainframes, SOA & Integration
- <<As we saw in the first part of this two-part article, companies are
increasingly turning to Web services and service-oriented architecture
(SOA) as a way to get mainframes to talk to the entire enterprise,
which is built on newer technology and applications which mainframes
typically can't run. So Web services are used to merge the
intelligence and data from the mainframe with other enterprise
applications, in a process called legacy-enablement. All that sounds
clean, neat and simple, but of course it's not. There are plenty of
problems with the process, as we'll see in this column.
Problems with Legacy Enablement
The first potential problem with using Web services and SOAs for
legacy enablement is a surprising one, according to Mike Oara,
co-founder and Chief Technology Officer for Relativity Technologies --
it's finding exactly where a piece of functionality is even located on
"Someone from the business side of the company may want to include a
particular piece of functionality, or data from the mainframe, and so
they ask that it be included in an application," he explains, setting
up a typical scenario. "But often, it's not at all obvious where that
functionality is; it's often buried. So the first problem someone will
come across is finding where the functionality is, and then finding
the connection point to it."
Another common problem, he says, is that when a program is written to
integrate with a mainframe, it executes, and essentially takes a path
to nowhere -- it gets stuck sending a query and receiving the response.
A potentially larger problem than both of those looms, though, he
warns. The world of the mainframe and the world of Web services are
separate ones, and in a way they have their own culture and languages
-- and they certainly have very different expertise. So someone
familiar with a mainframe may know all about COBOL, but he will have
no idea how to use WSDL to expose information to a Web service, for
example. And those who are familiar with Web services generally have
no idea how to work with mainframes. Bridging the technology gap
between the two can be exceedingly difficult.
Ron Schmelzer, senior analyst with ZapThink, notes that there is
another problem as well: What he calls the "granularity issue."
"The people who built mainframes didn't intend to have the data
accessed by non-mainframe apps," he says, "and sometimes the data on
mainframes is only accessible in very big chunks. The problem is that
with Web services you often need a very small piece of data, and
there's no API for the mainframe to help you get it. That means you
need some way to remediate between the two."
In addition, he says, there are a variety of security issues,
including different rules and procedures for logons on mainframes
versus Web services.>>
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