The old adage tells us that you can’t teach an old dog new tricks. But after the last three days, I beg to differ! It’s been an interesting few days for sure; fun, challenging, rewarding and heated are all words that come to mind when reflecting on the last few days. But at this point, three days into a four-day engagement, I think that we may just have dispelled that old adage. For one this “old dog” certainly feels like he has learned several new tricks.
So what was the gig? It was to visit a company that has an extensive application deployed on OpenVMS, and to help them to explore possible ways to extend the reach of those applications beyond the current OpenVMS platform. Not so hard I hear you say, there are any number of ways of doing that. xfServerPlus immediately comes to mind, as do xfODBC and the SQL Connection API, and even things like the HTTP API that could be used to allow the OpenVMS application to do things like interacting with web services. All true, but there was one thing that was threatening to throw a “spanner (wrench) in the works”. Did I mention that the application in question was developed in COBOL? That’s right, not a line of DBL code anywhere in sight! Oh and by the way, until about a week ago I’d never even seen a single line of COBOL code.
Now perhaps you understand the reason that challenging was one of the words I mentioned earlier. But I’m up for a challenge, as long as I think I have a fighting chance of coming up with something cool that addresses a customers needs. And in this case I did. I didn’t yet know all of the details, but I figured the odds of coming up with something were pretty good.
Why all of this confidence? Well, partly because I’m really good at what I do (can’t believe I just said that), but seriously, it was mainly because of the fact that a lot of the really cool things that we developers just take for granted these days, like the ability to write Synergy .NET code and call it from C#, or write VB.NET code and call it from Synergy .NET, have their roots in innovations that were made 30+ years ago by a company named Digital Equipment Corporation (DEC).
You see OpenVMS had this little thing called the Common Language Environment. In a nutshell this meant that the operating system provided a core environment in which programming languages could interoperate. Any language that chose to play in that ball park would be compatible with other such languages, and most languages on OpenVMS (incuding DIBOL and DBL) did just that. This meant that BASIC could call FORTRAN, FORTRAN could call C, C could call PASCAL and … well you get the idea. Any YES it means that COBOL can call DBL and DBL can call COBOL. OK, now we’re talking!
So why is this such a big deal? Well it turns out that Digital, later Compaq, and later still HP didn’t do such a great job of protecting their customers investments in their COBOL code. It’s been quite a while since there was a new release of COBOL on OpenVMS, so it’s been quite a while since OpenVMS COBOL developers had access to any new features. This means that there isn’t a way to call OpenVMS COBOL routines from .NET or Java, there isn’t a way for OpenVMS COBOL code to interact with SQL Server or Oracle, and there isn’t an HTTP API … so don’t even think about calling web services from COBOL code.
But wait a minute, COBOL can call DBL … and DBL can call COBOL … so YES, COBOL CAN do all of those things … via DBL! And that fact was essentially the basis for my visit to Toronto this week.
I’m not going to get into lots of details about exactly what we did. Suffice it to say that we were able to leverage two core Synergy/DE technologies in order to implement two main things:
The two core technologies have already been mentioned. Outbound from OpenVMS was achieved by COBOL calling a DBL routine that in turn used the Synergy HTTP API to communicate with a WCF REST web service that was hosted in a Windows application running in the users system tray. Inbound to OpenVMS was of course achieved with a combination of xfNetLink .NET and xfServerPlus.
So just who is the old dog? Well as I mentioned earlier I probably fall into that category at this point, as do several of the other developers that it was my privilege to work with this week. But as I set out to write this article I must admit that the main old dogs in my mind were OpenVMS and COBOL. Whatever, I think that all of the old dogs learned new tricks this week.
It’s been an action packed three days but I’m pretty pleased with what has been accomplished, and I think the customer is too. I have one more day on site tomorrow to wrap up the more mundane things like documentation (yawn) and code walkthroughs to ensure that everyone understands what was done and how all the pieces fit together. Then it’s back home on Friday before a well deserved vacation next week, on a beach, with my wife.
So what did I learn this week?