[rabbitmq-discuss] several further questions

Thu Jun 7 13:06:21 BST 2012

Thank you! that make thing clear for me.

> Hi,
>
> On 06/06/12 11:19, pangj wrote:
>> * What's the difference between "consume" and "get" for a consumer?
>
> The one is asynchronous and the other synchronous. When a client uses
> "consume" the broker will deliver messages as soon as any are available,
> while with "get" the client needs to poll the broker.
>
>> * Where to setup the message acknowledgment?
>
> Clients decide on this via the "no-ack" parameter of the "basic.consume"
> or "basic.get" methods.
>
> http://www.rabbitmq.com/amqp-0-9-1-reference.html#basic.consume.no-ack
> http://www.rabbitmq.com/amqp-0-9-1-reference.html#basic.get.no-ack
>
>> * If message acknowledgment is enabled, will the consumer send the ACK
>> automatically, or by a method call?
>
> If the consumer set "no-ack/auto-ack" true then the broker will not
> expect acknowledgements from the consumer.
> If the consumer set "no-ack/auto-ack" false then the consumer must
> acknowledge messages using the basic.ack method:
>
> http://www.rabbitmq.com/amqp-0-9-1-quickref.html#basic.ack
>
> Also see section "2.1.2.1 Message Life-cycle" in the 0.9.1 AMQP
> specification for a more detailed description.
>
>> * Any guide for transaction? for example, commit and rollback a
>> transaction.
>
> Transactions are discouraged, but see this for more details:
> http://www.rabbitmq.com/semantics.html#tx
> http://www.rabbitmq.com/amqp-0-9-1-quickref.html#class.tx
>
> Publisher confirms are recommended instead of transactions:
> http://www.rabbitmq.com/extensions.html#publishing
>
>
>
> -Emile
>
>