For today it was planned to learn SQL and Continues Integration. In this blog post I’m going to express few thoughts on Continuous Integration. Only thoughts, because you can read comprehensive articles on it over the internet, like this one written by Martin Fowler.

My definition of CI:

I took picture somewhere from web, since I like how it illustrates CI

Few main suggestions on introducing CI:

• Make sure that all sources needed for build are withing one Repository accessed by developers
• Any developer should be able check-out sources on virgin machine and be ready to go
• Everyone does commits regularly (once a day as a must), if someone complains about this you should mentor and convince him
• Build is automatically started on commit event
• Build should be as fast as it can
• If build couldn’t be fast you should consider sub-project builds and primary-secondary builds
• Developer is responsible for his commit so he should verify feedback from build system to see if build was ok and if tests passed
• Create continuous deployment process to the environments close to production, say once a day
• Execute automated tests on deployed system
• Consider using some CI engine, like Hudson

And some thoughts about blind architectors

When, I came to the project and I faced lot of difficulties that project had, like having sources under different repositories, having not automated procedure of builds, also when someone failed build, everyone knew about that next day and all QA work was stopped; lot of complains about merging sources; dry applying sources to diff versions procedures. None knew what is going with project till next day! I was junior at that moment I did not know about CI, but, hey where our architects have been? Thanks to efforts of new fresh architects we’ve got CI and it applies to our project very smoothly. What is left is to convince devs do committs more often and cover everything with Unit Tests. (But that has also something to do with our project specifics.)

Why didn’t they consider introducing CI earlier? This is mysterious question, I do not understand. There should be definitely something significant (like CI) that we can improve!