Timing Constraint Annotation¶
Overview¶
Splash offers timing semantics for specifying the time constraints for real-time stream processing. Splash supports four timing constraints: (1) freshness constraint, (2) correlation constraint, (3) latency constraint and (4) rate constraint.
1. Freshness Constraint¶
The freshness constraint is the time at which a given stream data element is valid after the data element is generated. It is annotated on a port.
For a port , let denotes a set of sources used to produce a data element for .
Since Pythagoras, we know that .