CHAPTER 1

Apuntes

CHAPTER 1 Reliable, Scalable, and Maintainable Applications The Internet was done so well that most people think of it as a natural resource like the Pacific Ocean, rather than something that was man-made. When was the last time a tech‐ nology with a scale like that was so error-free? —Alan Kay, in interview with Dr Dobb’s Journal (2012) Many applications today are data-intensive, as opposed to compute-intensive. Raw CPU power is rarely a limiting factor for these applications—bigger problems are usually the amount of data, the complexity of data, and the speed at which it is changing. A data-intensive application is typically built from standard building blocks that pro‐ vide commonly needed functionality. For example, many applications need to: • Store data so that they, or another application, can find it again later ( databases) • Remember the result of an expensive operation, to speed up reads ( caches) • Allow users to search data by keyword or filter it in various ways ( search indexes) • Send a message to another process, to be handled asynchronously ( stream pro‐ cessing) • Periodically crunch a large amount of accumulated data ( batch processing) If that sounds painfully ...