Yoctol Message Queue

The package provide two pattern of message queue:

- Queue
- Pubsub

Usage

``bash
$ yarn add @yoctol/message-queue
`

Queue

The queue has two driver: 'memory' and 'rabbitmq'.

$3

`js
import { connectQueue } from '@yoctol/message-queue';

const queue = await connectQueue({ driver: 'memory', queueName: 'queueName' });
`

$3

`js
import { connectQueue } from '@yoctol/message-queue';

const queue = await connectQueue({
driver: 'rabbitmq',
queueName: 'queueName',
amqpConfig: {
url: 'amqp://localhost',
},
deadLetterConfig: {
waitExchange: 'wait-exchange',
maxRetryCount: 3,
delayFactor: 1000,
retryJitter: true,
}
});
`

#### Enabling Dead Letter Handling in RabbitMQ Queue
When given deadLetterConfig, the dead letter handling flow will be enabled.
Enabling this feature will automatic retry dead letter messages(which throws errors during executing consume handler) with exponential back off with/without jitter.

To enable dead letter handling, you can follow the settings:
`js
const queue = await connectQueue({
driver: 'rabbitmq',
amqpConfig: {
url: 'amqp://localhost',
},
queueName: 'queueName',
deadLetterConfig: {
waitExchange: 'wait-exchange', // The exchange will be created with the name given
maxRetryCount: 3, // If retry amount exceed the maxRetryCount, the reachMaxRetryHandler will be called
delayFactor: 1000, // The final delay time (in milliseconds) is generate by this formula: delayFactor * delay base time (2^retryCount if retry jitter is disabled)
retryJitter: true, // If retryJitter is enabled, the delay base time will be random integer from 1 to 2^retryCount
}
});

// If retry amount exceed the maxRetryCount, the reachMaxRetryHandler will be called with (err, bufferMsg)
queue.consume(handler, reachMaxRetryHandler)
`

PubSub

The pubsub has three driver: 'memory' and 'postgres', and 'rabbitmq'.

$3

`js
import { connectPubsub } from '@yoctol/message-queue';

const pubsub = await connectPubsub({ driver: 'memory' });
`

$3

We use pg as client, see https://github.com/brianc/node-postgres for config info.

`js
import { connectPubsub } from '@yoctol/message-queue';

// for more info, check https://github.com/brianc/node-postgres
const config = {
host: process.env.DATABASE_HOST,
port: process.env.DATABASE_PORT,
database: process.env.DATABASE_NAME,
user: process.env.DATABASE_USER,
password: process.env.DATABASE_PASSWORD,
};
const pubsub = await connectPubsub({
driver: 'postgres',
pgConfig: config,
});
`

$3

`js
import { connectPubsub } from '@yoctol/message-queue';

const pubsub = await connectPubsub({
driver: 'rabbitmq',
amqpConfig: {
url: 'amqp://localhost',
exchange: 'amqp.exchange',
connectOptions: {
//node-amqp-connection-manager connect() options
heartbeatIntervalInSeconds: 5,
...
connectionOptions: {
//amqplib connection options
...
},
},
createChannelOptions: {
//node-amqp-connection-manager createChannel() options
name: 'channelName',
setup: ...,
json: true,
},
},
});
``