Tag Archives: Configuration Management

Configuration Management – Part 3: The Journey Begins

Today I want to tell you about a configuration management solution I have developed. It is built for Software AG‘s ESB (the webMethods Integration Server). The latter did, for a very long time, not have built-in capabilities for dealing with configuration values. So what many projects did, was to hack together a quick-and-dirty “solution” that was basically a wrapper around Java properties.

At the time (early 2008) I was working in a “SWAT” team in presales, where we dealt with large prospects that typically looked for a strategic solution to their integration requirements. Of course configuration management, although not as prevalent as today, came up more and more often. So instead of trying to dodge the bullet, I started working on a solution. And since webMethods Integration Server is built on an open architecture, you can easily add things.

So let’s dive into some of the details of my configuration management solution, called
WxConfig. Its overall design goal was to have packages (roughly the platform’s equivalent to a web application on servlet containers) that could be moved around without any additional manual setup or configuration. The latter is a requirement stemming from the fact that we are in an ESB/integration context. By definition most packages therefore have some “relationship” to the outside world, and are not an application running more or less in isolation. Typical example would be a connection to a database, or an ERP system.

Traditionally there were two approaches for dealing with these external environment dependencies. On development (DEV) environments, there was some kind of document, telling the developer what setup/configuration they would have to apply to their DEV environment. For all “higher” stages like test (TEST) or production (PROD) this was hopefully handled by some kind automation; although back in 2008 that was rarely case and more often than not also there a manual checklist was used.

From a presales perspective (that is where it all started) the DEV part was the relevant one. My idea was to come up with something that could transform the document with the setup instructions into some kind of codification. So I basically devised an XML format (or rather a convention) that did just that. It started out quite small, with only schedulers being supported. (In that specific case we needed a periodic execution of logic for a demo.)

Since then a lot of other things were added. The approach was so successful that  many customers have moved their entire environment setup (well, at least those parts that are supported) to the WxConfig solution. And there are, interestingly enough, quite a few customers who use WxConfig solely for environment configuration but not for configuring their actual applications.

You may now ask: Hang on, what about the other environments, like TEST and PROD? Very good question! This is one of the core strengths of the WxConfig solution and therefore warrants a separate post. Stay tuned …

Configuration Management – Part 2: Splendid Isolation

After the first post on configuration management, today I want to write about what I consider one of the biggest flaws in all systems I am aware about so far. They all live pretty much in “splendid isolation” and ignore whatever surrounds them.

My professional background is integration software and I attribute it to this fact, that for me it is a rather obvious real-world requirement to not ignore what is around you, but connect with it. In the past this was typically applied to applications on the business level. So having the ERP system talk with the CRM and SCM applications is well-established. But of course only your own imagination stops you from doing the same for other software. For an example, please check my post on integration of ALM software.

So what specifically makes integration an interesting aspect of configuration management? There are many different “layers” of configuration management out there. It starts with the infrastructure where you typically find a CMDB (Configuration Management Database), that contains information about computers and other components (esp. network). Then there are tools like Chef, Puppet, Ansible etc. that manage the operating system. (I know that is quite a simplification, because you can obviously handle other aspects that way as well; and I have done that extensively.)

A whole “new” level comes into play with containers like Docker. They come, again, with their own tools to manage configuration and operations. Then there is infrastructure-level software like databases, middleware, application servers, etc.

And last but not least, you finally hit the actual application. This is, by the way, the only, if any, level that the business will be interested in. They do not care about the vast complexity underneath, the interdependencies, etc. But of course they expect us to deliver value fast, without interruptions or failures, and for as little money as possible.

If there is no well-managed link between all those layers (and of course the number of layers needs to be multiplied by the number of environment types), how could you be able to handle things, let alone handle them well?

This is why I firmly believe, you need integration, governance, workflow capabilities etc. around configuration management.

Configuration Management – Part 1: The Horrors

Why is Configuration Management (CM) so important? The simple answer is: Because the correct configuration is one of the three critical parts for running a non-trivial piece of software successfully. (The other two are the actual code and the data.)

I still remember my first project when I was fresh out of university. While the team was great, everything else was a bloody nightmare. In particular the software, for which we developed, did not support configuration management in any way. Staging was basically done by exporting from the development system (DEV), manually finding and changing values in the export (at least it was plain ASCII), and importing it on the test system (TEST), and so on.

As if this wasn’t bad enough, there actually was no TEST environment. The customer had decided to save the money, so we had a combined DEV+TEST system. So more than once we ended up with the production system (PROD) accessing the DEV+TEST database. You may ask why we did not simply write a script to change the various settings automatically. Well, we were not allowed to, because it was not budgeted for.

And it gets even worse, because I actually lied to you when describing the staging process before. The problem was that while the export from one environment worked fine, the import into another did not after some time. It was basically a limitation of the maximum size the import file could could have. Our solution (after consultation with the vendor!) was to shut down both environments (DEV+TEST and PROD) and copy the binary storage files that held the development from one to the other. Then all the relevant values had to be adjusted manually on PROD, and then a test to be performed.

Of course that test failed a couple of times until all the changes had been done and recognized by the system (caching can be a dangerous thing). And because we were interfacing with at least five other systems (all PROD!) such a test run was not so easy. To make things more complicated, every set of test data (to be manually prepared on all surrounding systems) could only be used once. So we made a lot of “friends” with the folks operating the other systems.

We pulled a few all-nighters and somehow got things up and running (there were many other nice things with the software, of course). But it was frustrating and very inefficient. Since then configuration has been something that I deeply care about. And you probably understand why now.