Database updates not propagated to the search index

warningbusiness-updates-without-index-propagation

Application servers write this database and the design keeps a search index, but nothing captures the database's changes. The index then depends on the application writing to both places, and the two drift apart silently.

Severity: warning
Selects: every node of kind sql-database
Components in scope: 76

What it checks

It looks at every node of kind sql-database, and fires when:

— all of these hold:
— the node has at least one synchronous incoming edge from an app-server
— the design contains a node of kind search-index
— this does not hold:
— the node has at least one outgoing edge to a change-data-capture

Message

Database '{{node.id}}' is written by application servers and the design has a search index, but no change-data-capture propagates its updates. Index writes rely on dual writes.

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

Applies to · 76 components

SQL database sql-database

Tripped by · 12

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.

airbnb-searchreference booking-searchreference etsy-searchreference facebook-taoreference gitlab-architecturereference lyft-envoyreference notion-shardingreference proximity-servicereference stack-overflowreference twitch-livereference twitter-timelinereference uber-dispatchreference

Source

1# yaml-language-server: $schema=../schema/rule.schema.json
2# Application servers write this system of record and the design keeps a search index, but
3# no change-data-capture leaves the database. Index updates then depend on dual writes from
4# application code, which drift silently. Tripped by: designs/twitter-timeline.broken.yaml
5schemaVersion: "1"
6type: "rule"
7id: "business-updates-without-index-propagation"
8severity: "warning"
9select:
10  node:
11    kind: "sql-database"
12when:
13  all:
14    - hasEdge:
15        direction: "in"
16        mode: "sync"
17        peerKind: "app-server"
18    - hasNode:
19        kind: "search-index"
20    - not:
21        hasEdge:
22          direction: "out"
23          peerKind: "change-data-capture"
24message: "Database '{{node.id}}' is written by application servers and the design has a search index, but no change-data-capture propagates its updates. Index writes rely on dual writes."

The same page as markdown, for an agent: /catalogue/rules/business-updates-without-index-propagation.md