Friday, June 26, 2009

Done Environment

In addition to intelligent version control, I like to have a set of “test environments” that map closely to my Agile Version Control policy.

First, it is necessary to have some sort of “Development Environment” where the most recent code from the Development Branch in the version control system can be tested and worked on.

Similarly, I like to have a “Done Environment” (sometimes also known as “Next Release Environment”, or “NR Environment”) where the most recent code from the Done Branch can be seen. The power of this environment is that it allows (forces) you to integration test early. If your Done Environment is an accurate representation (e.g. replica) of your live environment then you will be able to integration- and system test as early as the first story being delivered there – and I always include in the Default Definition of Done that the story should be working and available for demo in the Done Environment. In fact, I like to setup an automatic build and distribution script here, that every night packages the most recent version of the Done Branch in the version control system and puts it on the Done Environment. This way you know that you will always be able to see the stories that are Done-Done on in this environment, without any risk of them being infected by code in progress. This also means that once the release day comes you have (hopefully) already done a lot of the steps required, and consequently making a release becomes less of a deal than it otherwise often is; avoiding or at least minimizing the Big Bang problem.

If you’re short on servers, server-space and/or money (actually, regardless) I think it is a great idea to use virtual servers for hosting the environments. It gives a great flexibility when it comes to setting up new environments and cloning existing ones. If you have a live environment consisting of 40 physical servers, and you want to replicate that environment as a Done Environment, it’s not always practical to buy 40 new physical servers. Especially not if you have three teams and each has its own Done Branch, and consequently needs its own Done Environment (3 x 40 servers ;-)). But maybe it is OK to buy just a few physical servers, and instead run the Done Environment servers virtually. Virtual servers is a great and powerful tool – try it. You can find a list of software here: http://en.wikipedia.org/wiki/Comparison_of_platform_virtual_machines

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