Skip to main content

Fire Alarms and Software


Some years ago, I got into the habit of using fire alarms as a metaphor for continuous integration and automated tests. My take was that organizations were always holding back resources to get servers for continuous integration, especially where project funding was provided by the business side. Simple reason: the management didn't really grasp concepts like automated tests and CI. I know that the metaphor doesn't completely fit in many ways, but it's a nice way to communicate the urgency and importance of having this security around. So I started using terms like "security net" and fire-safety to illustrate our need for a build-server.


It also is a handy metaphor when convincing developers to write tests for their code. Many developers fail to see the immediate benefits of practicing TDD, for example, but everyone has the fear of fire, or letting a bug slip by and into production.

I like comparing the team to the fire squad in a small city. The more fire alarms we've got distributed throughout buildings in the city, the bigger chance there is that we will get there in time to put out the fire and prevent any serious damage. For software, the more unit tests we've got distributed throughout the components in the code base, the bigger the chance that any bug-causing commit will break the build, and we can "move out" out and fix it.

Even though a smoke detector is not a guarantee that fire will be discovered in your apartment, having one in every room will drastically increase the chances that fire is detected. You could say the same for unit tests, and stopping bugs from getting into production.

You can use the metaphor to explain some related (mal)practices as well:
  • Having bad code is like having lots of flammable material lying around.
  • You can passively enforce safety by building fire-resistant material. This could be good code.
  • Your production error logs and exception handling are like fire alarms.
  • I might be stretching it a bit far here, but sprinklers could be like fail-early systems. Components that shut down in case of bugs, preventing any more damaging usage.
  • 30% of smoke detectors are said to be non-operating (faulty, batteries, etc). You could use this to explain that your tests need maintenance as well.
Well, like any metaphor, it can be taken too far, so I'll stop there.

PS: A funny thing about apartments here in Germany is that there aren't so many smoke detectors around. I'm sure that there are plenty of smart people who get these for their own safety, but it's not required by law. In Norway you are required to have at least one smoke detector in every house or apartment.
Labels:

Comments

  1. Peter2/4/10 20:32

    Great example of analogy! I really like it!
    Recently I started posting interestnig analogies I found on the web on blog.ygolana.com. I thought it could be a good idea to create a place where people can share useful analogies.

    ReplyDelete

Post a Comment

Popular posts from this blog

Open source CMS evaluations

I have now seen three more or less serious open source CMS reviews. First guy to hit the field was Matt Raible ( 1 2 3 4 ), ending up with Drupal , Joomla , Magnolia , OpenCms and MeshCMS being runner-ups. Then there is OpenAdvantage that tries out a handful ( Drupal , Exponent CMS , Lenya , Mambo , and Silva ), including Plone which they use for their own site (funny/annoying that the entire site has no RSS-feeds, nor is it possible to comment on the articles), following Matt's approach by exluding many CMS that seem not to fit the criteria. It is somewhat strange that OpenAdvantage cuts away Magnolia because it "Requires J2EE server; difficult to install and configure; more of a framework than CMS", and proceed to include Apache Lenya in the full evaluation. Magnolia does not require a J2EE server. It runs on Tomcat just like Lenya does (maybe it's an idea to bundle Magnolia with Jetty to make it seem more lightweight). I'm still sure that OpenAdvant
6 comments
Read more

Encrypting and Decrypting with Spring

I was recently working with protecting some sensitive data in a typical Java application with a database underneath. We convert the data on its way out of the application using Spring Security Crypto Utilities . It "was decided" that we'd be doing AES with a key-length of 256 , and this just happens to be the kind of encryption Spring crypto does out of the box. Sweet! The big aber is that whatever JRE is running the application has to be patched with Oracle's JCE  in order to do 256 bits. It's a fascinating story , the short version being that U.S. companies are restricted from exporting various encryption algorithms to certain countries, and some countries are restricted from importing them. Once I had patched my JRE with the JCE, I found it fascinating how straight forward it was to encrypt and decrypt using the Spring Encryptors. So just for fun at the weekend, I threw together a little desktop app that will encrypt and decrypt stuff for the given password
Post a Comment
Read more

What I've Learned After a Month of Podcasting

So, it's been about a month since I launched   GitMinutes , and wow, it's been a fun ride. I have gotten a lot of feedback, and a lot more downloads/listeners than I had expected! Judging the numbers is hard, but a generous estimate is that somewhere around 2000-3000 have listened to the podcast, and about 500-1000 regularly download. Considering that only a percentage of my target audience actively listen to podcasts, these are some pretty good numbers. I've heard that 10% of the general population in the western world regularly listen to podcasts (probably a bit higher percentage among Git users), so I like to think I've reached a big chunk of the Git pros out there. GitMinutes has gathered 110 followers on Twitter, and 63, erm.. circlers on Google+, and it has received 117 +'es! And it's been flattr'ed twice :) Here are some of the things I learned during this last month: Conceptually.. Starting my own sandbox podcast for trying out everythin
Post a Comment
Read more

The academical approach

Oops, seems I to published this post prematurely by hitting some Blogger keyboard shortcut. I've been sitting for some minutes trying to figure out how to approach the JavaZone talk mentioned in my previous blog-post. Note that I have already submitted an abstract to the comittee, and that I won't publish the abstract here in the blog. Now of course the abstract is pretty detailed on what the talk is going to be about, but I've still got some elbow room on how to "implement" the talk. I will use this blog as a tool to get my aim right on how to present the talk, what examples to include, what the slides should look like, and how to make it most straightforward and understandable for the audience. Now in lack of having done any presentations at a larger conference before, I'm gonna dig into what I learned at the University, which wasn't very much, but they did teach me how to write a research paper, a skill which I will adapt into creating my talk: The one
1 comment
Read more

Managing dot-files with vcsh and myrepos

Say I want to get my dot-files out on a new computer. Here's what I do: # install vcsh & myrepos via apt/brew/etc vcsh clone https://github.com/tfnico/config-mr.git mr mr update Done! All dot-files are ready to use and in place. No deploy command, no linking up symlinks to the files . No checking/out in my entire home directory as a Git repository. Yet, all my dot-files are neatly kept in fine-grained repositories, and any changes I make are immediately ready to be committed: config-atom.git     -> ~/.atom/* config-mr.git     -> ~/.mrconfig     -> ~/.config/mr/* config-tmuxinator.git       -> ~/.tmuxinator/* config-vim.git     -> ~/.vimrc     -> ~/.vim/* config-bin.git        -> ~/bin/* config-git.git               -> ~/.gitconfig config-tmux.git       -> ~/.tmux.conf     config-zsh.git     -> ~/.zshrc How can this be? The key here is to use vcsh to keep track of your dot-files, and its partner myrepos/mr for o
Post a Comment
Read more