In the early days of underground mining, the canary in the mine often had a short and valuable life. Because they are sensitive to deadly gases such as methane and carbon monoxide, the canary that falls off the perch is a clear signal that it is time to leave the miners. After a while, if the new Canary is safe, the miners can safely return to the mine.
Your software project can also have its own mine canary. If you are using continuous integration tools such as CruiseControl, you are likely to be familiar with e-mail messages sent to the team when the build fails. This is a signal that some parts of the project code need to be corrected immediately. However, when there are many other messages in your Inbox, these messages are sometimes ignored. Then, before I knew the message, I had updated the local copy from the problematic repository, or went straight home to let the other people in the team complain.
It takes something highly visible, like a canary, to see the state of the continuous build process after a quick glance. My canary is a new open-source technology from Sun Microsystems, its name is Sun Small programmable Object Technology (SPOT). This article describes the SPOT and shows how to build a build monitor for monitoring CruiseControl.
What is SPOT?
SPOT (see Figure 1) is a small wireless device that runs a Java™ program. The SPOT contains a number of sensors for monitoring its environment, as well as a set of color LEDs for communication with the outside, and two buttons for providing basic feedback. I use LEDs to show the state of the build. Some spot can be connected by a USB cable as a base station where other spot can access resources on the workstation, such as a database or WEB application.
Figure 1. Sun SPOT