CODEWITHSUNDEEP
rabbitmq
Rahul
Rahul

Reputation: 41

rabbitmq multiple consumer and multiple publisher

Want to know the behavior of rabbitmq multiple publisher and consumer. Does rabbitmq server gives one message to any one of the consumer at a time and other consumers are ideal at that time?

OR

Consumers pick any unattended message from queue, so that at a time, more than one consumers are consuming the message from queue?

Basically I am designing a database queue and do not want more than one inserts at a time.

Upvotes: 0

Views: 8644

Answers (2)

Sagar Varpe
Sagar Varpe

Reputation: 3599

yes , RabitMQ supports multiple publisher and consumer.

  1. Multiple Publisher

    For publishing a messsge to rabbitmqyou need to declare a factory and do a connection to the rabbitmq server. then decare a chennel to rabbitmq 

    ConnectionFactory FACTORY = new ConnectionFactory

    FACTORY.setUsername ("guest")

    FACTORY.setPassword ("guest")

    FACTORY.setVirtualHost ("\")

    FACTORY.setPort (5572)

    FACTORY.setHost ("localhost")

    Connection connection=FACTORY.newConnection Channel channel = connection.createChannel

the basic key to route a message is a routing key 

channel.basicPublish(EXCHANGE_NAME, "Queue1", MessageProperties.PERSISTENT_TEXT_PLAIN, "msg1".getBytes)

channel.basicPublish(EXCHANGE_NAME, "Queue2", MessageProperties.PERSISTENT_TEXT_PLAIN, "msg2".getBytes)

these two messages will be published to a seperate queue as per the routing key as mention queue1 and queue2

2.Multiple Consumer

for multiple consumer we declare a queue and bind to a particular routing key the the message to that routing key will be publishe to respected queue.

  channel.exchangeDeclare(EXCHANGE_NAME, "direct", durable)
  channel.queueDeclare("q1", durable, false, false, null)
  channel queueBind ("q1", EXCHANGE_NAME,"queue1")// routing key = "queue1"
  val q1Consumer = new QueueingConsumer(channel)
  channel basicConsume ("q1", false, q1Consumer)

like this u can consume messages from first queue and same goes for second queue but specify the routing key as "queue2"

  channel.exchangeDeclare(EXCHANGE_NAME, "direct", durable)
      channel.queueDeclare("q2", durable, false, false, null)
      channel queueBind ("q2", EXCHANGE_NAME,"queue2") // routing key = "queue2"
      val q2Consumer = new QueueingConsumer(channel)
      channel basicConsume ("q2", false, q2Consumer)

Upvotes: -2

Marek
Marek

Reputation: 3509

A message from the queue will be delivered to one consumer only. Ie: once the message makes its way to the queue - it won't be copied (broadcasted) to multiple consumers.

If you want to do broadcast - you have to use multiple queues.

See this tutorial for more details: http://www.rabbitmq.com/tutorial-two-python.html

Upvotes: 0

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