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Message-ID: <ec6e67fd0606230405v75621346h1eab9e3d594b027@mail.gmail.com>
Date: Fri, 23 Jun 2006 13:05:16 +0200
From: "James Strachan" <james.strachan@gmail.com>
To: activemq-users@geronimo.apache.org
Subject: Re: Clustering Topic Consumers
In-Reply-To: <5009495.post@talk.nabble.com>
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References: <5009495.post@talk.nabble.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 <eric@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.
>
>


-- 

James
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http://radio.weblogs.com/0112098/