Message queue

Queuemessage-queue

Broker-backed work queue drawn without naming a product.

Provider: default
Kind: Queue
Category: Messaging
Official docs: not recorded

Properties · 2 set by this component

property	type	values	required	kind default	this component
backoff	enum	none \| fixed \| exponential \| exponential-jitter	no	—	inherited
deadLetterQueue	boolean	—	no	false	inherited
delivery	enum	at-most-once \| at-least-once \| exactly-once	yes	—	▸ at-least-once
instances	integer	—	no	—	inherited
managed	boolean	—	no	false	▸ false
maxAttempts	integer	—	no	—	inherited
ordering	enum	none \| per-key \| global	no	none	inherited
persistence	boolean	—	no	true	inherited
replay	boolean	—	no	false	inherited
retentionDays	integer	—	no	—	inherited
role	enum	work \| dlq \| retry \| offline-mailbox \| frontier	no	work	inherited

Rules that apply · 3

Every rule whose selector covers this component's kind or its category. Whether a rule fires depends on the design: its properties, its edges and its groups.

Queue without dead-letter queueerror

queue-missing-dlq

A queue that receives asynchronous traffic and has no dead-letter queue either drops poison messages or retries them forever. Neither outcome leaves anything for a human to investigate.

— all of these hold:
— the node's `deadLetterQueue` is false
— the node has at least one asynchronous incoming edge

Retry queue without dead-letter queueerror

retry-queue-without-dlq

A retry queue is where poison messages end up. With no dead-letter queue they are retried forever or dropped in silence, and nobody ever looks at the failed payment.

— all of these hold:
— the node's `role` is "retry"
— the node's `deadLetterQueue` is false

Retry queue without backoffwarning

retry-without-backoff

Retrying a transient failure at full speed turns one slow dependency into a retry storm. A retry queue backs off, preferably exponentially and with jitter.

— all of these hold:
— the node's `role` is "retry"
— any of these hold:
— the node's `backoff` has no value
— the node's `backoff` is "none"

Use it in a design

nodes:
  - { id: "message-queue", component: "message-queue" }

Other Queue products · 23

Source

1# yaml-language-server: $schema=../../schema/component.schema.json
2# Generic message queue: a broker-backed work queue whose product the design does not name.
3# Only the guarantee every broker offers is assumed (at-least-once); dead-letter queue,
4# replay and retention stay unset so a design has to state them.
5schemaVersion: "1"
6type: "component"
7id: "message-queue"
8kind: "queue"
9provider: "default"
10defaults:
11  delivery: "at-least-once"
12  managed: false

The same page as markdown, for an agent: /catalogue/components/message-queue.md