Sequence

Sequence Nodes in Cortex are designed for Complex Event Processing (CEP), focusing on detecting sequences of events that occur consecutively over time. Unlike Pattern Nodes, Sequence Nodes require all matching events to arrive in direct succession without any intervening non-matching events.

Purpose: The primary function of Sequence Nodes is to identify and process sequences of events that follow one another directly, enhancing CEP capabilities by ensuring strict sequential order without gaps of unrelated events. This specificity is crucial for scenarios where the order and continuity of events are critical for accurate detection and processing.

Configuration Steps:

1. States Creation: Users can establish multiple States within a Sequence Node, each representing a phase in the event sequence analysis. Each State can encompass up to two occurrences, non-occurrences, and counting conditions, tailored to sequential event patterns.

2. Conditions and Time Limits: Conditions for occurrences, non-occurrences, and counting can be set for each State, with the option to apply time constraints for non-occurrences and an overarching time limit for the entire Sequence Node. This configuration ensures tight control over the timing and sequence of events.

3. State Progression: States sequentially process events from Stream Nodes, with the transition from one State to the next contingent upon the fulfillment of the current State’s conditions. For a Sequence Node, it is imperative that these conditions are met in direct succession for the node to progress. The node completes its sequence analysis once all States evaluate to True consecutively, at which point it forwards the output attributes from the final State to the next Node.

Sequence Nodes are integral to Cortex for applications requiring precise sequential event analysis, providing a robust framework for detecting and acting upon consecutively occurring event sequences within real-time data streams.