Abstract: The Kentik Data Engine (KDE) is an integrated real-time, big data software system able to analyze what exactly is happening on a network at the present moment, and what happened on the network over the a prior period of time. KDE collects live operational data from computer network infrastructure devices (routers and switches) and computer hosts, consisting of multiple data types, categories, and protocols, and correlates them to analyze network activity and health. KDE does this in a lossless manner, meaning that it retains all raw data rather than summarizing or aggregating prior to storage. In this way, KDE provides a combination of precise, actionable information in real-time as well as a complete forensic data store for detailed exploratory analysis.