Rohan Desai

One potential benefit of using a stream processor like Kafka Streams to build applications on the log is the ability to time travel. What if you could go back in time and query state stores to see when a bug was introduced? Or what if you could freeze the state of a running application and make a copy to do pre-deploy testing? This potential has largely gone unrealized because of a missing primitive in Kafka Streams - the ability to create a consistent snapshot that can be read and even cloned into a new application. Until now. We first explain exactly what snapshots and clones are. In short, a snapshot contains all the application's state up to some point in time, and no state after. A clone is a copied application created from this state. Next, we’ll make the case for why snapshots are a game-changing feature for Kafka Streams. Snapshots take your application into a multiverse (or otter-verse) of histories + branches. We’ll show how you can use them to explore your application’s history, interactively debug, test changes against real data, do blue/green deploys, and more. The remainder of the talk dives into the theory + practice of Kafka Streams snapshots. First we cover what’s…