linux.conf.au 2010: Day 4
Lindsay Holmwood: Flapjack
Lindsay introduced Flapjack, which is a monitoring system designed to meet the scalability and extensibility requirements of cloud deployments. It shares the Nagios plugin interface, and so can use the same checks. It uses beanstalkd as a central message queue to coordinate the work of executing checks, recording results and making the appropriate notifications. Each of its components (worker, notifier, database) can be extended or replaced using an API, providing a great deal of flexibility.
Jeremy Allison: Microsoft and Free Software
Jeremy took us through Microsoft’s recognition of, and response to, the threat of free software to their monopoly position. After reviewing the major legal battles of this ongoing war (and the metaphor is apt), he says that Microsoft is turning to patents in an attempt to split the free software community and to earn revenue from the use of free software. Jeremy predicts that the outcome will be a never-ending conflict.
The key conflicts are likely to be around netbooks, mobile phones and appliances. How should the free software community respond?
We could ignore it, and keep making free software under copyleft licenses. Jeremy points out that this is perhaps our most effective strategy in the long run, to stay focused on the vision of a free software world.
We can continue to pressure governments and corporations to adopt truly open standards, and to investigate and challenge monopolies. Transparency is key to these efforts, as “elephants like to work in the dark” (Microsoft being “the elephant in the room”).
By lobbying against software patents, we can hope to contain the US software patent system from the rest of the world. Otherwise, the rapidly accumulating software patents in the US can suddenly and dramatically spread.
We might even convince the likes of Microsoft that patents, and patent trolls, represent a greater harm than good.
In response to direct patent attacks, we should search for prior art and attempt to undermine unjust patents. He also suggests calling out Microsoft employees on the company’s actions, to promote awareness particularly in the context of free software conferences.
He closed with a hope that Microsoft could change, citing IBM as having been “as feared and hated as Microsoft is today”.
Neil Brown:Digging for Design Patterns
Neil explored various design patterns in the kernel in order to illustrate how they are discovered, what their important attributes are, and how to use them effectively.
His examples were a binary search, “goto err”, accessor functions and kref. Naming patterns is important, especially getting that name into the code itself, so that it helps to cross-reference use, implementation and documentation of the pattern (e.g. uses of the kref pattern are sprinkled with the word “kref”). A successful pattern can both help to find bugs (this binary search doesn’t look the same as that one…why?) and to avoid bugs (by getting it right the first time).