bcquality/microsoft/knowledge/performance/keep-event-subscribers-lightweight.md
Jesper Schulz-Wedde 9a4198eb28 Add [all] sentinel to bc-version; apply to version-agnostic knowledge
Most of the corpus — FindSet/SetLoadFields/CalcFields patterns, permission
sets, SingleInstance codeunits, DataClassification, IsolatedStorage,
transaction scope, SecretText — describes BC platform behaviour that is
identical across supported versions. The seed [26..28] range on every
file implied a version-specificity the content does not actually have,
and there was no way to express "applies to every version" in the
schema the way [w1] and [all] already do for countries and
application-area.

Extend the v1 schema with a universal sentinel for bc-version, parallel
to the sentinels already defined for the other dimensions:

  bc-version: [all]         # applies to every BC version

[all] is mutually exclusive with explicit versions. Range shorthand
([26..28]) and explicit lists ([26, 27, 28]) continue to work for files
genuinely tied to a version-gated API or deprecation.

Update read.md (field definition, matching semantics, partial-context
rule), write.md (default to [all], use ranges only with a concrete
reason), README.md (frontmatter example), and the CI validator. All
forty existing knowledge files and the three action skills convert to
[all]; none of the current content is version-gated. Validator passes.
2026-04-23 16:00:03 +02:00

1.2 KiB

bc-version domain keywords technologies countries application-area
all
performance
event
subscriber
publisher
extension
al
w1
all

Keep event subscribers lightweight

Seed article. Converted from an existing performance-review prompt to bootstrap the BCQuality performance corpus. Domain stewards should expand, restructure, and refine as needed.

Description

Event subscribers run synchronously on the publisher's thread. If a subscriber does heavy work — a database query, a web service call, a layout render — every caller of the publisher pays that cost. Subscribers on hot events (OnAfterValidate on common fields, OnBeforeInsert on ledger-entry-like tables) can multiply a small per-call cost into a system-wide regression.

Best Practice

Keep subscribers small: guard early with inexpensive checks, defer heavy work to a task queue or a background session, and cache results across invocations when the data is stable.

Anti Pattern

Calling an external web service, running a report, or iterating a large table from inside an event subscriber on a hot publisher makes every operation on that publisher as slow as the heaviest subscriber.

See sample: keep-event-subscribers-lightweight.bad.al.