Configuration

You can pass an optional configuration object as the second argument to EdgeWorker.start() to tweak the worker’s behavior.

Zero configuration needed

All configuration options are optional and have good defaults.

You only need to provide the handler function:

EdgeWorker.start(console.log);

Default configuration

EdgeWorker.start(handler, {
  // name of the queue to poll for messages
  queueName: 'tasks',

  // how many tasks are processed at the same time
  maxConcurrent: 10,

  // how many connections to the database are opened
  maxPgConnections: 4,

  // in-worker polling interval
  maxPollSeconds: 5,

  // in-database polling interval
  pollIntervalMs: 200,

  // how long to wait before retrying a failed job
  retryDelay: 5,

  // how many times to retry a failed job
  retryLimit: 0,

  // how long a job is invisible after reading
  // if not successful, will reappear after this time
  visibilityTimeout: 3,
});

Queue and polling

queueName

Type: string Default: 'tasks'

The name of the PGMQ queue to listen to for messages.

You don't need to create queues manually

The worker will automatically create a logged, non-partitioned queue with configured name during startup if it does not exist.

EdgeWorker.start(handler, {
  queueName: 'my-custom-queue'
});

maxPollSeconds

Type: number Default: 5

Amount of seconds to wait for a message to be available in the queue.

EdgeWorker.start(handler, {
  maxPollSeconds: 5 // Long-poll for 5 seconds waiting for a message
});

pollIntervalMs

Type: number Default: 200

The interval for in-database polling that pgmq.read_with_poll does. Most of the time, you don’t need to change this value.

Caution

This value should be lower than the maxPollSeconds value.

EdgeWorker.start(handler, {
  pollIntervalMs: 300 // Poll every 300ms
});

Retries

retryDelay

Type: number Default: 5

Amount of seconds to wait between retry attempts.

Caution

This value should be greater than the visibility timeout.

EdgeWorker.start(handler, {
  retryDelay: 5 // Wait 5 seconds between retries
});

retryLimit

Type: number Default: 5

Maximum number of retry attempts for failed message processing before marking the message as dead.

Set to 0 to disable retries.

EdgeWorker.start(handler, {
  retryLimit: 0 // retries are disabled
});

visibilityTimeout

Type: number Default: 3

The duration in seconds that a message is hidden from other consumers while being processed.

Timeouts

Make sure to set it bigger than max time your task can take to complete, otherwise it will be processed multiple times.

Work-in-Progress

This option is probably subject to be refactored to timeoutMs that will affect timeout for the tasks (wip) and visibility timeout. Do not rely on this option heavily for now!

EdgeWorker.start(handler, {
  visibilityTimeout: 5 // message will re-appear in queue after 5 seconds if not processed
});

Concurrency

maxConcurrent

Type: number Default: 10

This option limits concurrency - the maximum number of messages that can be processed at the same time. Increase for IO-heavy tasks (network or db calls), decrease for CPU-heavy tasks.

EdgeWorker.start(handler, {
  maxConcurrent: 10 // Process up to 10 messages at once
});

maxPgConnections

Type: number Default: 4

This option limits the number of connections to the database. Increase for IO-heavy tasks (network or db calls), decrease for CPU-heavy tasks.

EdgeWorker.start(handler, {
  maxPgConnections: 10 // Use up to 10 connections to the database
});