Real-World Event Sourcing

Introducing Cloud Events

Whether injecting, emitting, or internally processing, a number of pieces of information are typically required for every event. Events need a timestamp, a type, and typically things like a unique ID, an origin, and a handful of other metadata. If our event store can ensure things like global ordering, regular timestamps are sufficient. If not, then in a widely distributed system we might need to look into things like CRDTs (conflict-free replicated data types)^[9] or Lamport^[10] clocks (concepts outside the scope of this book). We’re going to be using tools and apps throughout the book that won’t require us to do things the “hard way” with CRDTs.

Having a common way of transmitting events over the wire means that many ...