lab08-clustered-queue.md

Lab 8. Clustered Queue

Create a clustered queue

To have a clustered queue it must be defined in both brokers.

1. Add an anycast queue configuration to both brokers.

     <address name="clusteredQueue">
        <anycast>
               <queue name="clusteredQueue" />
        </anycast>
     </address>

2. Restart the brokers

Run a consumer connected to each broker

1. In broker1

   $ ./artemis consumer --message-count 5 --destination queue://clusteredQueue

2. In broker2

   $ ./artemis consumer --message-count 5 --url tcp://localhost:61716 --destination queue://clusteredQueue

3. Now run the producer connected to broker1 and send 10 messages

   $ ./artemis producer --message-count 10 --destination queue://clusteredQueue

   You will see each consumer receives 5 messages in a round robin fashion

Run a disconnected consumer

1. Now run the producer first again

   $ ./artemis producer --message-count 10 --destination queue://clusteredQueue

2. Run the broker2 consumer first

   $ ./artemis consumer --message-count 10 --url tcp://localhost:61716 --destination queue://clusteredQueue

3. Run the broker1 consumer next

   $ ./artemis consumer --message-count 10 --destination queue://clusteredQueue

   You will see that only 1 consumer received the messages as they were load balanced on demand

Message load balancing strategy

1. Update the load balancing to strict in the etc/broker.xml file

   <cluster-connections>
         <cluster-connection name="my-cluster">
            <connector-ref>artemis</connector-ref>
            <message-load-balancing>STRICT</message-load-balancing>
            <max-hops>1</max-hops>
            <discovery-group-ref discovery-group-name="dg-group1"/>
         </cluster-connection>
   </cluster-connections>

2. Restart the brokers and run again the previous exercise

   You will notice that both the consumers receive messages even when disconnected

End of Lab 8.