Thursday, September 07, 2006

Configuration is the new code

Fairly recently I was thinking about the development processes for the configuration of a large, off the shelf system. you know the type; CRM, ERP, TLA ;), that kind of thing. All things to all people, completely generic, no need to do any development to get it just right for you business, just a bit of configuration needed.

Only it's not just a bit of configuration, it's a lot of configuration. And with the business world the way it is, it's ongoing configuration much the same as it's ongoing development for every other bit of software we have.

So, if we're going to have a team of people continually working on configuring this system, configuring the system is basically changing the behaviour of the system, then what differentiates it from source code?

As far as I'm concerned, nothing.

When the configuration of the system goes as far as it does on the particular system (and it's not alone), then the configuration of the system has to be dealt with as if it's the source code of that system. It has to undergo the same quality checks, regression tests, audited rollout processes, version control.

The particular product I was looking at has had some functionality added to support these kinds of ideas. It has a clear migration method to get from development to test to staging to live. It supports that kind of structured, scripted rollout. But the config (development) tool can be attached straight to the live environment and be used to 'just make a quick change'. And there's nothing you can do to lock it down.

The configuration all lives in a database, so you can't just simply check the configuration in and out of version control. The development tool does has some version control integration, but it doesn't allow you to branch, tag or, most importantly, revert. Not only that, but the dev tool can be used to change any number of configuration sets, but when you flick between them the version control module you're using doesn't change. So you can check a config from one environment into the version control module of another!

So I find I have to ask the question... What's the point in having the option if it's so hopelessly crippled?

My only conclusion is that there is none!

Anyway, the process isn't completely doomed, there is a process that will allow us to make sure our release versions are version controlled and tagged, and therefore audited.

Unfortunately, since the solution means putting a single binary (rather than multiple files) into version control we loose many of the day to day benefits of version control, like granular logs of changes and the ability to diff. But hey, at least our process is auditable.

The whole way through the examination I was told by consultants that "most people don't do this" and "I've never worked on a project where people thought version control was necessary". Probably very true... But that's because a lot of the industry doesn't know what it's doing when it comes to software development.
It's a big shame, because the inclusion of the migration tools and the lip service towards integrated version control points to the fact that they've started to think about it. It's just that it's not very well thought out yet.

On day soon, the big players will wake up, provide the proper tools for version controlling their configurations and maybe then the rest of the industry will learn to use it.

Hopefully, the Google Test conference I'm attending this week will give me some ideas on how to add automated regression tesing, and plug another gap in their toolset...


William Robertson said...

Very good points. I found myself wondering the same thing last time I looked at Informatica Powercenter and Control M job scheduler. Possibly these have improved in the last couple of years since I used them, but it seemed that they let you create arbitrarily complex systems by clicking and dragging boxes, selecting options and typing in parameters. Both promised something better than programming but actually gave you something much worse when it came to debugging, version control, reporting and so on.

Anonymous said...

Yes, config is the new code, and hiding config in @annotations doesn't make it any easier to maintain, just harder to tune later on in the build process.

I hope you noted that smartfrog tries to solve this, and you can contact your oracle colleage hal hildebrand for info on how he's be using it (and an less biased opinion).

One thing to think about configuration is that it is too important to leave to the ops team.

-steve loughran