Article

Demonstrating Red Hat JBoss AMQ 7 HA Replication Failover

August 4, 2017
Java
Hugo Guerrero
Hugo Guerrero
APIs & Integration Technical Evangelist, Red Hat
AMQ Replication HA Policy

A few weeks ago, the newest version of Red Hat JBoss AMQ was released. AMQ 7 is the result of Red Hat’s efforts on creating a unified messaging platform for its middleware offerings. One of the most interesting features of this new version is the new backing strategy for failovering when configured in high availability. This feature allows clients connections to migrate from one server to another in the event of server failure so client applications can continue to operate.

AMQ 6.x already had an option to configure failover using a shared store, usually backed up by a shared filesystem or a JDBC connection to a database. However, that option involved the use of external infrastructure add-on in hardware and software, representing an increase in overall deployment costs.

In AMQ 7, support for network-based replication was added. When using replication, the live and the backup servers do not share the same data directories; all data synchronization is done over the network. Therefore, all (persistent) data received by the live server will be duplicated to the backup.

amq-ha-replicated

The above figure shows the basics of AMQ 7 replication ha policy.

The Replication (Shared Nothing) Demo project is a demonstration of the new AMQ 7 replicated high availability feature to avoid using a shared store. This project demonstrates how to set up a live broker and its corresponding backup using AMQ’s command line interface (CLI) and configure the replication ha fail-over policy.

You will need a Linux or Mac laptop with at least 2GB RAM (4GB preferred) and a couple of GB of free disk space. A Java Virtual Machine version 8 should be installed in the system as well. With those prerequisites covered, you can deploy your brokers following the next steps:

  1. Download and unzip this demo of clone the Github repository.
  2. Download the JBoss AMQ Broker from Red Hat Developer Portal: —download here; add to installs directory (see installs/README).
  3. Deploy the demo using the automated installation script ‘init.sh’,
    ./init.sh

    After successfully deployed, you can test the failover.

Sending messages

To send messages to the master broker, execute the following command: 

$ target/amq-broker-7.0.1/instances/replicatedMaster/bin/artemis producer --message-count 10 --url "tcp://127.0.0.1:61616" --destination queue://haQueue

Browse messages on Master

To check the messages, which were successfully sent to the broker, check the queue in the broker web console.

  • Open a web browser and navigate to the AMQ web console, http://localhost:8161/hawtio.
  • In the left tree navigate to 127.0.0.1 > addresses > haQueue > queues > anycast > haQueue.
  • Click on Browse (refresh if necessary).

You will see the 10 messages sent by the producer script.

Browse backup Console

As the replicatedSlave broker is running as a backup broker for replicatedMaster, there are no active addresses or queues listening.

  • Open a web browser and navigate to the AMQ web console http://localhost:8261/hawtio
  • In the left tree navigate to 127.0.0.1 > addresses > haQueue > queues > anycast > haQueue

You will only see the information regarding the cluster broadcast configuration.

Master shutdown

To shutdown the master broker, execute the following command: 

$ target/amq-broker-7.0.1/instances/replicatedMaster/bin/artemis-service stop

While the master is shutting down, the backup broker will notice the disconnection from the master and will become live.

Browse messages on Slave

To check the messages that were successfully replicated to the slave broker, check the queue in the slave broker web console.

  • Refresh the AMQ web console http://localhost:8261/hawtio
  • In the left tree navigate to 127.0.0.1 > addresses > haQueue > queues > anycast > haQueue
  • Click on Browse (refresh if necessary)

You will see the 10 messages sent by the producer script to the master broker.

Failback

If you want, you can start again the replicated Master broker to see how the backup failbacks to the master. 

$ target/amq-broker-7.0.1/instances/replicatedMaster/bin/artemis-service start

The master will start and check if there is a live broker when the backup detects that the master has become available again, it fails back going into a backup mode again.

Now you are up and running with a fully installed and backed up AMQ 7 broker!

For more information, check the Red Hat Developers Program site that provides useful blogs and content about Red Hat JBoss AMQ.

Download  Red Hat JBoss AMQ for development use.

Last updated: August 3, 2017

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