eventelle

Eventelle is a term used in discussions of event-driven data systems. It denotes a discrete unit of an event that can be independently observed, stored, and routed within an event stream. In typical usage, an eventelle includes a unique identifier, a timestamp, a type or category, and a payload with the substantive data. The structure is often described as immutable and serializable to support replay and auditing.

The word is a neologism formed from the English word event and the diminutive suffix -elle, and it has appeared in technical discussions and some vendor materials since the early 2010s. There is no single canonical definition, and different communities may adopt variations on the concept.

In practice, eventelles are used to model streams in event-sourced architectures, change data capture pipelines, and other streaming workflows. They serve as the atomic unit for processing, routing, and persisting events, allowing systems to reconstruct state by replaying a sequence of eventelles.

Critics note that the lack of standardization can hinder cross-system interoperability, and some favor more established terms such as event, record, or message. Proponents argue that eventelle highlights the atomic, immutable nature of each unit and can aid in formal modeling of event streams.

See also: event-driven architecture, event sourcing, stream processing, change data capture.