[rabbitmq-discuss] Are publisher confirms at all aware of HA (replicated) durable queues?

Wed Oct 5 15:16:37 BST 2011

Hmm.  While I do see a publisher confirmation from the broker, I don't
actually see the message in the queues.  (When I say "event" below, I
really mean "message", sorry.)  Any idea what I should suspect that I
could be doing wrong on the producer side?

Thanks, --Steve

On Wed, Oct 5, 2011 at 9:54 AM, Steve Rehrauer <steve.rehrauer at gmail.com> wrote:
> Okay, thanks.
>
> I'm trying to chase down why I'm not seeing all the events I've
> published, in a test that shuts down the master node while events are
> being produced.  Am trying to understand what I might be doing wrong.
> Good to know that I can rely on robust publisher confirms!
>
> I've pruned the test back to a very simple thing now.  I have two
> nodes in the cluster.
>
> 1. With both nodes running, I produce an event.
> 2. I verify that I can consume this event.  I verify that I get a
> publisher confirmation from the broker.
> 3. Using Alice, I stop the master node.
> 4. I produce another event.
> 5. I verify that I can consume this event.
>
> I'm not seeing the event from step 5.  I wonder if I'm not properly
> setting up the consumer?
>
> When I stop the master node in step 3, I see the consumer catch a
> ShutdownSignalException, with "reason:
> {#method<connection.close>(reply-code=320,
> reply-text=CONNECTION_FORCED - broker forced connection closure with
> reason 'shutdown'".  The consumer reconnects to the broker,
> successfully as far as I can tell.
>
> When I try to produce another event in step 4, the producer also
> catches a ShutdownSignalException, with "clean connection shutdown;
> reason: Attempt to use closed channel".  The producer also reconnects
> to the broker, successfully as far as I can tell.
>
> After the producer reconnects, I see it succeed in basicPublish().  I
> also see a publish confirmation from the broker for this event.
>
> However, the consumer is never seeing it.
>
> Q1: Is it surprising that the producer sees this in step 4?  I assumed
> that it would be the same for the producer as for the consumer; if the
> master node goes down, both sides must reconnect to the broker?
>
> Q2: I think I am asking for consumer cancellation notification in the
> consumer, but I never see the callback happen.  Should I expect to, in
> the scenario I've outlined above?  I'm now a little concerned I'm not
> setting it up properly, and this is why my consumer never sees this
> event.  Here's the Java code that I use, which is in a class that
> derives from RabbitMQ's ConnectionFactory.
>
>   public DerivedConnectionFactory() {
>      super();
>
>      ...
>
>        Map<String, Object> clientProperties = new HashMap<String, Object>();
>        clientProperties.put(
>               "consumer_cancel_notify",
>                Boolean.valueOf(true)
>                );
>        this.setClientProperties(clientProperties);
>   }
>
> Thanks, --Steve
>
> On Wed, Oct 5, 2011 at 5:18 AM, Matthias Radestock
> <matthias at rabbitmq.com> wrote:
>> Steve,
>>
>> On 04/10/11 18:05, Steve Rehrauer wrote:
>>>
>>> If I'm asking the broker for publisher confirms, and I have a cluster
>>> of nodes, and I have durable queues that are replicated (x-ha-policy:
>>> "all"), does the broker send the confirm as soon as a message is
>>> persisted in the queues of the master node?  It doesn't wait for those
>>> queues to be replicated to the slaves?
>>
>> From http://www.rabbitmq.com/ha.html#behaviour
>>
>> <quote>
>> As the chosen slave becomes the master, no messages that are published to
>> the mirrored-queue during this time will be lost: messages published to a
>> mirrored-queue are always published directly to the master and all slaves.
>> Thus should the master fail, the messages continue to be sent to the slaves
>> and will be added to the queue once the promotion of a slave to the master
>> completes.
>>
>> Similarly, messages published by clients using publisher confirms will still
>> be confirmed correctly even if the master (or any slaves) fail between the
>> message being published and the message being able to be confirmed to the
>> publisher.
>> </quote>
>>
>> Matthias.
>>
>