sequenceevents

Sequenceevents are individual occurrences that are captured as part of an ordered sequence. They are used to model processes where the timeline and the order of events matter, such as workflows, simulations, and event-driven architectures.

A sequenceevent typically includes: sequence_id to identify the sequence, position or index to indicate order, timestamp to record when the event happened, event_type to classify the event, and payload to carry domain-specific data. Some models also store source, correlation_id, and metadata.

Applications: In event sourcing, the system state is derived from a log of sequenceevents. In distributed systems, they enable ordered processing and traceability. In media and UI, they represent user actions or notes in a sequence, such as a music sequencer or animation timeline.

Implementation: Sequenceevents are produced by event streams, logs, or message queues. In reactive programming, an observable sequence emits sequenceevents. In databases and log systems, they are stored with offsets or sequence numbers to preserve order.

Challenges include preserving strict ordering, handling late arrival or out-of-order events, deduplicating repeated events, and ensuring idempotent processing. Design choices around timestamps (physical vs logical) and clock synchronization impact order guarantees.

See also: event log, event sourcing, stream processing, time series, tracing, observability.