Sunday, November 25, 2007

Impala being used on a "real" project

I'm pleased to say that I am now using Impala for what looks like may and should become a core and major development at the company where I am working. The results have been great. Progress has been more rapid than I have expected, and a lot of this is down to the capabilities provided by Impala.

I haven't run into any major obstacles that couldn't be overcome with relatively little effort. Dynamic reloading is working well. Test execution speed - a bugbear of the previous version - is quick. There are now around 200 tests, of which around 30 or so are integration tests which load up various bits of the application. The application currently consists of 21 Hibernate entities. Total execution time of all the tests - integration included- is about six to eight seconds for initial startup, plus the same again to run the tests.

It's a major moment for any open source project is when it gets its first real commercial user. In this case, the actual user is still primarily myself. That's a good thing - it means that on a day-by-day basis I am getting to validate the features and functionality, discover bugs when the appear, and get ideas for improvements and new features.

Successful open source projects are often extractions from existing successful commercial projects. Others are developed from a vision of the technology the developer would like to work with on his or her next project. Impala started off this way. The danger for the latter kind of projects is that the opportunities to use the technology in anger on real commercial projects may not present themselves that readily, with the danger that you don't get the chance to "eat your own dog food". At the moment, I am eating my own dog food by the spadeful, and it tastes good!

Tuesday, November 6, 2007

New package and domain names

I've been spending a bit of time working on the package layout of Impala classes. While the project is still at an early stage, it makes sense to try to get this right.

The first thing to do was to change the root package name. I've had to do this after moving the code from to Google code. The Impala root package is now org.impalaframework. It would have been nice to use org.impala, but I'm politely sticking to the convention that you should own the domain that you use (yes, I have actually bought the domain org.impalaframework!). I certainly didn't want to use com.googlecode; if I need to move the project again, then I don't want to have to do another root package rename. org.impalaframework is a bit wordy, but it at least there is a precedent in the form of the root package names used for Spring: org.springframework. Hope this doesn't make me too much of a copycat.

All this being said, the convention that you should to use a package name which corresponds to a domain name that you own kinda sucks. Of course, this is only a convention, and you can choose to ignore it. I may choose to do so, but for now, I'm more interested in getting the structure of the packages and classes right. That means getting the names of classes and packages right, getting their locations correct and eliminating package cycles. This process should settle down soon. It will need to before I'm ready to do the first public release.