@RabbitListener with multiple queues and its concurrency

[ddinde-mdsol]

Hello AMQP community

If I have multiple queues listening on the same @rabbitlistener with concurrency defined as 3-5. Will each queue have an individual set of 3-5 threads or all queues will have a total of 3-5 threads?

e.g. @RabbitListener(queues= {"Q1", "Q2", "Q3"}, concurrency="3-5")
Will Q1, Q2, and Q3 have 3-5 consumers allotted each or all queues will have only 3-5 consumers in total?

[artembilan]

Each queue is going to have that number of consumers:

				for (int i = 1; i <= this.concurrentConsumers; i++) {
					BlockingQueueConsumer consumer = createBlockingQueueConsumer();
...
	protected BlockingQueueConsumer createBlockingQueueConsumer() {
		BlockingQueueConsumer consumer;
		String[] queues = getQueueNames();
		// There's no point prefetching less than the tx size, otherwise the consumer will stall because the broker
		// didn't get an ack for delivered messages
		int actualPrefetchCount = getPrefetchCount() > this.batchSize ? getPrefetchCount() : this.batchSize;
		consumer = new BlockingQueueConsumer(getConnectionFactory(), getMessagePropertiesConverter(),
				this.cancellationLock, getAcknowledgeMode(), isChannelTransacted(), actualPrefetchCount,
				isDefaultRequeueRejected(), getConsumerArguments(), isNoLocal(), isExclusive(), queues);

See more in docs: https://docs.spring.io/spring-amqp/reference/html/#listener-concurrency

[ddinde-mdsol]

Thank you @artembilan