November 06, 2009 -
0 Comments -
ruby
tools
bluepill
god
At Serious Business, we’ve been using God to monitor long-running background tasks and other daemonized processes. While God provides a nice DSL for configuration, it has issues with memory leaks which forced us to keep a close eye on it (meta-monitoring?) and reboot it periodically via cron.
To remedy the problem, a few of the guys got together over a weekend and wrote Bluepill, a replacement monitoring tool with a DSL inspired by God, but written for low memory consumption. Check out Arya’s blog for a detailed explanation and breakdown of Bluepill’s features. See the graph comparing Bluepill and God memory consumption over time. You’re sold.
September 21, 2009 -
0 Comments -
tdd
Lately in test-driven development, I’ve noticed that I tend to write tests against invalid input before I get to tests against valid input. This is a subtle technique which I think merits some discussion.
One of the big wins with TDD is the way that it forces you to think about the problem in terms of the API; this pushes the engineer to design to an interface, not an implementation, which is one of the major takeaways from the original Gang of Four book on design patterns. And I think the higher-level concern that designing to an interface facilitates is the process of knowing the problem domain, which leads organically into the process of dividing up responsibilities between discrete classes and modules.
In many ways, a problem domain can be defined not only by what it’s supposed to do, but also by its constraints, the cases in which it should fail. Thinking about these cases upfront, testing against invalid or nonsensical inputs, leads to software which is more resilient to misuse and unexpected scenarios.
I find that defining these c…
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July 24, 2009 -
2 Comments -
ruby
rails
spam
tools
akismet
When I decided that I would roll code.isdangero.us as a custom-made blog in Rails, I thought of it as a fun, easy project. After all, blogs are simple, and the simplicity allows for plenty of room for attention to detail in making the code as tight as possible, similar to the way a haiku allows a poet to express his skill in language through the power of the simply-stated.
Of course, every project looks easy from a distance, because unforeseen problems are just that: unforeseen. It had been a while since I’d blogged, and therefore I had all but forgotten about the long war of blog software against the endless networks of compromised Windows machines turned into Viagra-pitching zombies, comparable in number to the mighty armies of ancient Persia.
Enter Akismet
Just as the 300 men under the command of King Leonidas of Sparta held back Persia’s onslaught by fighting in the shade, the forces of good in this war have gathered together their disparate forces into a collective known as Akismet.
Akismet is an API which tracks spam and ham submissions from participating blogs all over the world, building its knowledge of what spam looks like versus c…
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