Clustering Topic Consumers

[enortham <er...@aiosoft.com>]

Does anybody know if it is possible to have two nodes in an app server
cluster consume messages on the same topic and subscription without
consuming the same messages? Basically I want to use topics in a clustered
app server environment and not have the nodes in the cluster consume the
same messages.

If it's not possible has anyone found any interesting workarounds? I was
thinking of using composite destinations but the downside is that the
producer needs to be updated any time a new consumer would be added.
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Re: Clustering Topic Consumers

[James Strachan <ja...@gmail.com>]

The JMS specification mandates that a durable topic subscription
requires a unique clientID and subscriber name. So you cannot create 2
MessageConsumer instances for the same durable topic.

A workaround is to use a queue for each logical consumer. You can use
composite destinations (or add a virtual destination interceptor) to
map one logical 'topic' to multiple real queues that can be load
balanced across a cluster.
http://incubator.apache.org/activemq/composite-destinations.html

So whenever folks want 'load balancing' of messages, they want a queue really.

FWIW one day I'd like us to have an implementation of durable topics
where a durable topic subscription can be exposed as a virtual JMS
queue - so it can be browsed & load balanced.

http://issues.apache.org/activemq/browse/AMQ-452

On 6/23/06, enortham <er...@aiosoft.com> wrote:
>
> Does anybody know if it is possible to have two nodes in an app server
> cluster consume messages on the same topic and subscription without
> consuming the same messages? Basically I want to use topics in a clustered
> app server environment and not have the nodes in the cluster consume the
> same messages.
>
> If it's not possible has anyone found any interesting workarounds? I was
> thinking of using composite destinations but the downside is that the
> producer needs to be updated any time a new consumer would be added.
> --
> View this message in context: http://www.nabble.com/Clustering-Topic-Consumers-t1835532.html#a5009495
> Sent from the ActiveMQ - User forum at Nabble.com.
>
>


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James
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