Mailing-List: contact users-help@activemq.apache.org; run by ezmlm
Precedence: bulk
Reply-To: users@activemq.apache.org
Received-SPF: pass (herse.apache.org: domain of mteira@tid.es designates
 193.145.240.2 as permitted sender)
Date: Tue, 03 Apr 2007 09:36:24 +0200
From: Manuel Teira <mteira@tid.es>
Subject: Best approach for HA message broker + grid
Sender: mteira@tid.es
To: users@activemq.apache.org
Message-id: <461203F8.8030606@tid.es>
MIME-version: 1.0
Content-type: text/plain; format=flowed; charset=ISO-8859-1
Content-transfer-encoding: 7BIT
User-Agent: Thunderbird 1.5.0.10 (Windows/20070221)

Hello.

My aim is to have a set of brokers, running in different machines, to 
consume messages coming from different clients, to be able to scale the 
system for future needs. Furthermore, HA features are also required, to 
protect the system on hardware malfunction.

Looking at the alternatives that ActiveMQ provides to achieve these 
goals, it seems to me that I could get the grid behaviour using the 
"Network of Brokers" feature, where all the brokers are "alive".

I understand that  when more than one broker have consumers for a given 
queue, the messages are shared among them. But in my first tests, I've 
found that most of times, all the messages get consumed by one of the 
brokers. Could this be caused by a (default) high prefetch value?

Talking about the HA needs, I've read that a master-slave aproximation 
could be used, but here I won't have the grid behaviour benefits of the 
"Network of brokers" approach (as only one of the brokers is actually 
active). I would like to have a combined behaviour, where messages 
persist a hardware failure (better if restarting the failing node was 
not needed to restore them), and where messages were shared among 
consumers from different brokers.

I was thinking about using a "Network of Brokers" with a low prefetch 
value for the shared queues and disable journal files, to minimize the 
amount of messages "owned" by a given broker. As the database is located 
in a different machine, I could always restart  a new broker using the 
schema of the failing one. Is this a right approach?

Any other idea to implement this scenario?

Best regards.