Information Technology Reference
In-Depth Information
changes and forgets to commit a few files to the version control repos-
itory, the CI system, which is running on a separate machine, runs an
integration build and finds these omissions. Furthermore, you can put
application and database servers into known states each time an inte-
gration build occurs, which can reduce assumptions and enable much
faster discovery and resolution of problems. When individuals know
that the latest integration build failed, they can avoid getting the bad
source code from the version control repository. The integration build
machine acts as a safety net, ensuring that the software is working as
expected.
Often someone asks how much it costs to have a dedicated integra-
tion build machine. This is an important question and has an even
more important answer. The following scenario demonstrates how this
question plays out.
Peter (Technical Lead):
I'd like for us to purchase a dedicated integra-
tion build machine for our Logistics project.
Bill (Project Manager):
Why do you need a separate machine?
Peter:
So that we are able to build our software directly from our Sub-
version repository every time a change occurs. We will also have the
capability to clean and reapply the environment, including the test
data. All of this will allow us to find and fix problems sooner.
Bill:
That sounds good, Peter, but we really don't have the funds for
that. I am guessing it will cost at least $1,000 for this—is that right?
Peter:
The reason we had to come in last Saturday was because of
integration problems. By getting an integration build machine, we can
save considerable time and money. The time saved will easily pay for
the cost of the machine many times over. We had to manually inte-
grate and test before Monday's demo. We really need this machine to
integrate our software automatically with every change.
Bill:
Okay, what we can do is go ahead and use one of the extra
machines in the server room. You can remove everything on that
machine and make it your integration build machine.
As demonstrated in Bill and Peter's conversation, you don't need
to spend money to purchase a new machine. An extra machine that's
