sqs-consumer
Build SQS-based applications without the boilerplate. Just define an async function that handles the SQS message processing.
Installation
npm add sqs-consumer
Note: This library assumes you are using AWS SDK v3. If you are using v2, please install v5.5.0:
npm add sqs-consumer@5.5.0
Usage
import { Consumer } from 'sqs-consumer';
const app = Consumer.create({
queueUrl: 'https://sqs.eu-west-1.amazonaws.com/account-id/queue-name',
handleMessage: async (message) => {
// do some work with `message`
}
});
app.on('error', (err) => {
console.error(err.message);
});
app.on('processing_error', (err) => {
console.error(err.message);
});
app.start();
- The queue is polled continuously for messages using long polling.
- Messages are deleted from the queue once the handler function has completed successfully.
- Throwing an error (or returning a rejected promise) from the handler function will cause the message to be left on the queue. An SQS redrive policy can be used to move messages that cannot be processed to a dead letter queue.
- By default messages are processed one at a time – a new message won't be received until the first one has been processed. To process messages in parallel, use the
batchSize
option detailed below. - If you need to add specific configuration options to the SQS client, you may pass an instantiated client to the Consumer constructor:
import { Consumer } from 'sqs-consumer';
import { SQSClient } from '@aws-sdk/client-sqs';
const app = Consumer.create({
queueUrl: 'https://sqs.eu-west-1.amazonaws.com/account-id/queue-name',
handleMessage: async (message) => {
// do some work with `message`
},
sqs: new SQSClient({
region: 'my-region',
requestHandler: MyCustomHttpHandler
})
});
app.on('error', (err) => {
console.error(err.message);
});
app.on('processing_error', (err) => {
console.error(err.message);
});
app.start();
Credentials
By default the consumer will look for AWS credentials in the places specified by the AWS SDK. The simplest option is to export your credentials as environment variables:
export AWS_SECRET_ACCESS_KEY=...
export AWS_ACCESS_KEY_ID=...
If you need to specify your credentials manually, you can use a pre-configured instance of the SQS Client client and chose from a valid credentials provider
import { Consumer } from 'sqs-consumer';
import { SQSClient } from '@aws-sdk/client-sqs';
import { fromIni } from '@aws-sdk/credential-provider-ini';
const credentials = fromIni({
profile: 'my-profile'
});
const region = 'my-region';
const app = Consumer.create({
queueUrl: 'https://sqs.eu-west-1.amazonaws.com/account-id/queue-name',
handleMessage: async (message) => {
// ...
},
sqs: new SQSClient({ region, credentials })
});
app.on('error', (err) => {
console.error(err.message);
});
app.on('processing_error', (err) => {
console.error(err.message);
});
app.on('timeout_error', (err) => {
console.error(err.message);
});
app.start();
API
Consumer.create(options)
Creates a new SQS consumer.
Options
-
queueUrl
- String - The SQS queue URL -
region
- String - The AWS region (defaulteu-west-1
) -
handleMessage
- Function - Anasync
function (or function that returns aPromise
) to be called whenever a message is received. Receives an SQS message object as it's first argument. -
handleMessageBatch
- Function - Anasync
function (or function that returns aPromise
) to be called whenever a batch of messages is received. Similar tohandleMessage
but will receive the list of messages, not each message individually. If both are set,handleMessageBatch
overrideshandleMessage
. -
handleMessageTimeout
- Number - Time in ms to wait forhandleMessage
to process a message before timing out. Emitstimeout_error
on timeout. By default, ifhandleMessage
times out, the unprocessed message returns to the end of the queue. -
attributeNames
- Array - List of queue attributes to retrieve (i.e.['All', 'ApproximateFirstReceiveTimestamp', 'ApproximateReceiveCount']
). -
messageAttributeNames
- Array - List of message attributes to retrieve (i.e.['name', 'address']
). -
batchSize
- Number - The number of messages to request from SQS when polling (default1
). This cannot be higher than the AWS limit of 10. -
visibilityTimeout
- Number - The duration (in seconds) that the received messages are hidden from subsequent retrieve requests after being retrieved by a ReceiveMessage request. -
heartbeatInterval
- Number - The interval (in seconds) between requests to extend the message visibility timeout. On each heartbeat the visibility is extended by addingvisibilityTimeout
to the number of seconds since the start of the handler function. This value must less thanvisibilityTimeout
. -
terminateVisibilityTimeout
- Boolean - If true, sets the message visibility timeout to 0 after aprocessing_error
(defaults tofalse
). -
waitTimeSeconds
- Number - The duration (in seconds) for which the call will wait for a message to arrive in the queue before returning. -
authenticationErrorTimeout
- Number - The duration (in milliseconds) to wait before retrying after an authentication error (defaults to10000
). -
pollingWaitTimeMs
- Number - The duration (in milliseconds) to wait before repolling the queue (defaults to0
). -
sqs
- Object - An optional SQS Client object to use if you need to configure the client manually
consumer.start()
Start polling the queue for messages.
consumer.stop()
Stop polling the queue for messages.
consumer.isRunning
Returns the current polling state of the consumer: true
if it is actively polling, false
if it is not.
Events
Each consumer is an EventEmitter
and emits the following events:
Event | Params | Description |
---|---|---|
error |
err , [message]
|
Fired when an error occurs interacting with the queue. If the error correlates to a message, that error is included in Params |
processing_error |
err , message
|
Fired when an error occurs processing the message. |
timeout_error |
err , message
|
Fired when handleMessageTimeout is supplied as an option and if handleMessage times out. |
message_received |
message |
Fired when a message is received. |
message_processed |
message |
Fired when a message is successfully processed and removed from the queue. |
response_processed |
None | Fired after one batch of items (up to batchSize ) has been successfully processed. |
stopped |
None | Fired when the consumer finally stops its work. |
empty |
None | Fired when the queue is empty (All messages have been consumed). |
AWS IAM Permissions
Consumer will receive and delete messages from the SQS queue. Ensure sqs:ReceiveMessage
and sqs:DeleteMessage
access is granted on the queue being consumed.
Contributing
See contributing guidelines.