Event-time windows without watermark

warningwindowed-aggregation-without-watermark

Event-time windows need a watermark to know when a window is complete. Without one the processor either waits forever or closes windows early and silently drops late events.

Severity: warning
Selects: every node of kind stream-processor
Components in scope: 34

What it checks

It looks at every node of kind stream-processor, and fires when:

— all of these hold:
— the node's `windowing` is "event-time"
— the node's `watermarkSeconds` has no value

Message

Stream processor '{{node.id}}' windows by event time but declares no watermark. Late data handling is undefined.

{{node.id}} style paths are filled in from the node, the edge or the design the finding is about.

Applies to · 34 components

Stream processor stream-processor

Tripped by · 14

Reference designs whose broken twin names this rule in its header. The gate reads the same header, and fails when a rule no design trips.

ad-click-aggregationreference airbnb-searchreference doordash-deliveryreference gojek-platformreference google-mapsreference khan-academy-goliathreference linkedin-kafkareference lyft-envoyreference metrics-monitoringreference nubank-corereference pokemon-goreference spotify-playbackreference tiktok-recommendationreference x-recommendationreference

Source

1# yaml-language-server: $schema=../schema/rule.schema.json
2# Event-time windows need a watermark to know when a window is complete. Without one
3# the processor either waits forever or closes windows early and drops late events.
4# Tripped by: designs/doordash-delivery.broken.yaml
5schemaVersion: "1"
6type: "rule"
7id: "windowed-aggregation-without-watermark"
8severity: "warning"
9select:
10  node:
11    kind: "stream-processor"
12when:
13  all:
14    - prop: "windowing"
15      equals: "event-time"
16    - prop: "watermarkSeconds"
17      exists: false
18message: "Stream processor '{{node.id}}' windows by event time but declares no watermark. Late data handling is undefined."

The same page as markdown, for an agent: /catalogue/rules/windowed-aggregation-without-watermark.md