[rabbitmq-discuss] Data is feteched from the queue in random order

[Alexis Richardson]

Kamal

Apologies for our slow response...

Why do you think data is dequeued out of order?

alexis



On Wed, Apr 20, 2011 at 10:25 AM, Kamal  Nandan
<kamal.nandan at impetus.co.in> wrote:
> Hi,
>
>
>
> I am trying to dequeue data from the RabbitMQ. Why is it so that the data is
> not dequeued in the same order in which it was enqueued into the queue?
>
>
>
> I see that the data is dequeued in a random order. Is it an expected
> behavior?
>
>
>
> Following is the block of code that I am using to dequeue:
>
>
>
>
>
>       public int init(String hostName, int port, String userName, String
> password, String queueName) throws OceRecoverableException
>
>       {
>
>             if(true == LOG.isDebugEnabled()) {
>
>                   LOG.debug("Executing RabbitMqConsumer::init");
>
>             }
>
>
>
>             try {
>
>                   super.initialize(hostName, port, userName, password,
> queueName);
>
>             } catch (IOException ioe) {
>
>                   String message = "RabbitMQ consumer failed to create
> connection with the RabbitMQ server.";
>
>                   LOG.error( message + " [ERROR: " + ioe.getMessage() +
> "]");
>
>                   throw new OceRecoverableException(ioe);
>
>             }
>
>
>
>             this.queueingConsumer = new QueueingConsumer(this.channel);
> //channel is the member of parent class
>
>
>
>             try {
>
>                   this.channel.basicConsume(queueName, false,
> this.queueingConsumer);
>
>             } catch(IOException ioe) {
>
>                   String message = "RabbitMQ consumer failed to set the
> QueueingConsumer callback for consuming data.";
>
>                   LOG.error( message + " [ERROR: " + ioe.getMessage() +
> "]");
>
>                   throw new
> OceRecoverableException(ioe);
>
>             }
>
>
>
>             return 0;
>
>       }
>
>
>
>
>
>       public byte[] fetchMessage(int timeout) throws OceRecoverableException
>
>       {
>
>             LOG.debug("RabbitMqConsumer::fetchMessage");
>
>
>
>             if(this.channel == null)
>
>             {
>
>                   throw new OceRecoverableException("The channel is not
> initialized; Initilize the channel by calling init method");
>
>             }
>
>
>
>             QueueingConsumer.Delivery delivery;
>
>
>
>             try {
>
>                   delivery = this.queueingConsumer.nextDelivery(timeout);
>
>             } catch(Exception ex) {
>
>                   String message = "Error occurred while fetching data from
> the RabbitMQ server.";
>
>                   LOG.error( message + " [ERROR: " + ex.getMessage() + "]");
>
>                   throw new OceRecoverableException(ex);
>
>             }
>
>
>
>             if(delivery != null)
>
>             {
>
>                   try {
>
>
> this.channel.basicAck(delivery.getEnvelope().getDeliveryTag(), false);
>
>                   } catch (IOException ioe) {
>
>                         String message = "Error occurred while sending
> acknowledgement to the RabbitMQ server for the fetched message.";
>
>                         LOG.error( message + " [ERROR: " + ioe.getMessage()
> + "]");
>
>                         throw new OceRecoverableException(ioe);
>
>                   }
>
>
>
>                   byte[] body = delivery.getBody();
>
>                   return body;
>
>             }
>
>             else
>
>             {
>
>                   return null;
>
>             }
>
>       }
>
>
>
> }
>
>
>
>
>
> It would be great, if someone could guide me regarding this?  I want the
> data to be fetched in the order it was enqueued.
>
>
>
> Thanks & Regards,
>
> Kamal
>
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