@dcl/queue-consumer-component

A message consumer component that orchestrates event handling from an SQS queue. It polls messages, routes them to registered handlers based on event type/subType, and manages graceful shutdown.

Installation

npm install @dcl/queue-consumer-component

Usage

import { createQueueConsumerComponent } from '@dcl/queue-consumer-component'
import { createSqsComponent } from '@dcl/sqs-component'
import { Events } from '@dcl/schemas'

// Create the component with required dependencies
const queueConsumer = createQueueConsumerComponent(
  { sqs, logs },
  { releaseVisibilityTimeoutSeconds: 0 } // Optional: configure shutdown behavior
)

// Register handlers for specific event types
messagesHandler.addMessageHandler(Events.Type.CLIENT, Events.SubType.Client.LOGGED_IN, async (event) => {
  console.log('User logged in:', event.metadata.userId)
})

// Multiple handlers can be registered for the same type/subType
messagesHandler.addMessageHandler(Events.Type.CLIENT, Events.SubType.Client.LOGGED_IN, async (event) => {
  await analytics.track('login', event)
})

// Remove a handler when no longer needed
messagesHandler.removeMessageHandler(Events.Type.CLIENT, Events.SubType.Client.LOGGED_IN, myHandler)

Features

• Event-based routing: Register handlers for specific type/subType combinations from @dcl/schemas
• Multiple handlers: Multiple handlers can be registered for the same event type and all execute in parallel
• Automatic message deletion: Messages are deleted after processing (regardless of handler success/failure)
• Graceful shutdown: On stop, remaining unprocessed messages have their visibility timeout changed to make them available for other consumers
• Exponential backoff: Automatic retry with backoff when queue polling fails
• Error isolation: Handler errors are logged but don't affect other handlers or message processing

Configuration

| Option | Type | Default | Description | | --------------------------------- | -------- | ------- | ------------------------------------------------------------------------------------------------------------ | | releaseVisibilityTimeoutSeconds | number | 0 | Visibility timeout (in seconds) for unprocessed messages on shutdown. Set to 0 for immediate availability. |

License

Apache-2.0