Patterns

I finished reading three different architectural patterns - pipe and filters, layered systems and iterative refinement algorithms. It was good to read the short definitions of the problems and see how to write a pattern.

The pipes and filters and layered systems pattern we have discussed before. When put into this format, the main thing added over the previous papers was a Forces section and a more concise solution section. This allows an architect to gain a quick idea of how the pattern can be applied to a problem. The previous papers contained a lot more implementation details, showing the typical problems you might face and how to overcome them, and lessons learned from existing implementations. While needed when actually doing the implementing, the architect may not need it up front.

The iterative refinement algorithm was a new topic defining a pattern in algorithms where some steps are repeated until a good enough solution is produced. Having taken algorithms and data mining, I can see when this pattern could be useful, but I have not run across it on my job.