iii-queue

Asynchronous job processing with named queues, retries, and dead-letter support.

Supports two modes:

• Topic-based queues — register a consumer per topic, emit events via iii::durable::publish. Fan-out: every distinct function subscribed to a topic receives a copy of each message.
• Named queues — define queues in config, then enqueue function calls via TriggerAction.Enqueue. No trigger registration needed.

Sample Configuration

- name: iii-queue
  config:
    queue_configs:
      default:
        max_retries: 5
        concurrency: 5
        type: standard
      payment:
        max_retries: 10
        concurrency: 2
        type: fifo
        message_group_field: transaction_id
    adapter:
      name: builtin
      config:
        store_method: file_based
        file_path: ./data/queue_store

Configuration

Queue Configuration (queue_configs entries)

Queue Modes

When to use which

Standard vs FIFO Queues

Adapters

builtin

Built-in in-process queue. No external dependencies. Suitable for single-instance deployments.

name: builtin
config:
  store_method: file_based   # in_memory | file_based
  file_path: ./data/queue_store

redis

Uses Redis Pub/Sub for topic-based queues. Supports multi-instance deployments.

Note: The Redis adapter supports publishing to named queues but does not implement named queue consumption, retries, or dead-letter queues. For full named queue support in multi-instance deployments, use RabbitMQ.

name: redis
config:
  redis_url: ${REDIS_URL:redis://localhost:6379}

rabbitmq

Uses RabbitMQ for durable delivery, retries, and dead-letter queues across multiple engine instances.

name: rabbitmq
config:
  amqp_url: ${RABBITMQ_URL:amqp://localhost:5672}

Adapter Comparison

Builtin Functions

iii::durable::publish

Publishes a message to a topic-based queue. Fanned out to every distinct subscribed function.

iii::queue::redrive

Moves all messages from a named queue's dead-letter queue back to the main queue.

Returns: queue (string), redriven (number)

iii trigger \
  --function-id='iii::queue::redrive' \
  --payload='{"queue": "payment"}'