why can't messages be forwarded through the same broker more than once?

[bsnyder]

I'm using a network of brokers to consume messages and I'm seeing the
log message stating '... Ignoring sub ... already routed through this
broker once'. This is coming from the
DemandForwardingBridgeSupport.serviceRemoteConsumerAdvisory() method:

...
            if (contains(info.getBrokerPath(), localBrokerPath[0])) {
                // Ignore this consumer as it's a consumer we locally sent to
                // the broker.
                if (LOG.isDebugEnabled()) {
                    LOG.debug(configuration.getBrokerName() + "
Ignoring sub " + info + " already routed through this broker once");
                }
                return;
            }
...

My question is about why this is restricted in this manner? I can see
that we don't want message ping pong between brokers, but it seems it
should be finer grained than not allowed at all.

If I send 10 messages to brokerA, consume two messages from brokerB
and then a consumer hits brokerA, it won't be able to consume any
messages because they won't be forwarded back to brokerA because of
this rule. Maybe I'm overlooking a setting???

I'm also wondering why all messages are forwarded between brokers. If
a consumer becomes active on a broker in the network, all messages on
that queue are forwarded, regardless of whether they can be consumed
or not. This is what's causing messages to be stuck on brokerB in this
use case. Is there a workaround for this?

Bruce
--
perl -e 'print unpack("u30","D0G)U8V4\@4VYY9&5R\"F)R=6-E+G-N>61E<D\!G;6%I;\"YC;VT*"
);'

Apache ActiveMQ - http://activemq.org/
Apache Camel - http://activemq.org/camel/
Apache ServiceMix - http://servicemix.org/

Blog: http://bruceblog.org/

[bsnyder]

On Mon, Oct 13, 2008 at 11:34 AM, Bruce Snyder <bruce.snyder@...> wrote:

> I'm using a network of brokers to consume messages and I'm seeing the
> log message stating '... Ignoring sub ... already routed through this
> broker once'. This is coming from the
> DemandForwardingBridgeSupport.serviceRemoteConsumerAdvisory() method:
>
> ...
>            if (contains(info.getBrokerPath(), localBrokerPath[0])) {
>                // Ignore this consumer as it's a consumer we locally sent to
>                // the broker.
>                if (LOG.isDebugEnabled()) {
>                    LOG.debug(configuration.getBrokerName() + "
> Ignoring sub " + info + " already routed through this broker once");
>                }
>                return;
>            }
> ...
>
> My question is about why this is restricted in this manner? I can see
> that we don't want message ping pong between brokers, but it seems it
> should be finer grained than not allowed at all.
>
> If I send 10 messages to brokerA, consume two messages from brokerB
> and then a consumer hits brokerA, it won't be able to consume any
> messages because they won't be forwarded back to brokerA because of
> this rule. Maybe I'm overlooking a setting???
>
> I'm also wondering why all messages are forwarded between brokers. If
> a consumer becomes active on a broker in the network, all messages on
> that queue are forwarded, regardless of whether they can be consumed
> or not. This is what's causing messages to be stuck on brokerB in this
> use case. Is there a workaround for this?

Anyone???

Bruce
--
perl -e 'print unpack("u30","D0G)U8V4\@4VYY9&5R\"F)R=6-E+G-N>61E<D\!G;6%I;\"YC;VT*"
);'

Apache ActiveMQ - http://activemq.org/
Apache Camel - http://activemq.org/camel/
Apache ServiceMix - http://servicemix.org/

Blog: http://bruceblog.org/