Dear Kettle-devs,

Now that we released 3.2.0-stable to SourceForge, it makes sense to revisit the architecture of PDI a little bit.
If we want to have a shot at the big ticket items like version control integration etc, we need to do some cleanup.

Here are a few of the items that need to be tackled IMHO:

1) Get rid of the Messages files. I started to work on this with a little help and push from Mike D at Pentaho. Should be done later today.
2) Related to 1) is the clean up Step and Job entry categories code as well as the semi-hard-coded list of Job Entry types.
3) Reduce or re-factor out the use of Spring/Ognl in PDI where not absolutely needed to increase transparency.
4) Make it easier to load step/job-entry plugins from a certain folder.
5) Refactoring of the Repository classes and references (
6) Take a shot at simplifying step/jobentry plugin development though abstracting the XML and Repository (de-)serialization. Most likely with a helper UI.

Finally, James Dixon, our CTO is working on Object factories and other ways to make it easier to extend and embrace PDI so that we can at least take a shot at perhaps re-merging efforts with GeoKettle (for example).
This is related among other things to JIRA cases like

This may sound "external" or "invisible" to most of you out there but will most certainly lead to a series of major code-changes. Fear not : in all likelihood, things should become simpler, not harder.
The transformation engine seems to hold up pretty nicely so few changes are anticipated there in the medium to long term so there should be very few (if any) compatibility issues along the way.
The major challenge as I see it will be to be backward compatible with the existing plug-in architecture so that folks don't have to modify or re-compile their steps and job-entries.

As always, feel free to vent any concerns, opinions or suggestions that may help us to push forward.


Matt Casters
Chief Data Integration
mcasters (AT) pentaho (DOT) org
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