We'll present the architecture and implementation of a Node.js/DTrace-based distributed platform for analyzing the performance of cloud applications in real-time. We'll do a live demo on a real, internet-facing cloud and discuss some of the interesting performance pathologies we've found and explained using this tool.
Sometimes there is a mix between performance and scalability, but they are different dimensions. Changing your code from blocking to non-blocking yields scalability at the cost of a complexity. In this talk I show how Python, Ruby and JS do that, the differences between their async toolkits and some basic building blocks for web and high load applications.