It’s 2:00am. Is your application working properly? How will you know for sure when you wake up tomorrow morning? In this talk we’ll look at strategies for effective logging, monitoring and metrics collection from within your application. We’ll look at what kind of data you should and shouldn’t log, and with what frequency, as well as some great open-source tools to use. We’ll also take some first steps with Statsd and Graphite to help see trends in performance, user behavior, and overall application health. We’ll also learn some useful ways to interpret the data we collect to get the best picture of what’s really going on when you’re not looking.