Configuring Clustered Messaging in WildFly
In this guide, you will learn how to configure WildFly servers with an embedded ActiveMQ Artemis broker in a messaging cluster, enabling server-side message and client load balancing. It will demonstrate how to configure deployments, such as MDBs, EJBs, or Servlets, as well as external JMS clients, to load balance connections across all servers in the cluster.
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Note
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An ActiveMQ Artemis cluster is distinct from a standard WildFly cluster formed by the Infinispan subsystem. While a WildFly cluster using Infinispan focuses on data caching and session replication across nodes, an Artemis cluster is specifically designed for messaging, allowing message redistribution across brokers and load balancing of message producers and consumers. These two clusters operate independently, each with its own purpose and configuration, although they can coexist within the same WildFly environment. |
For a detailed explanation of ActiveMQ Artemis clusters, refer to the Apache ActiveMQ Artemis Clustering Documentation and the EAP 7.4 Messaging Clusters Overview.
Prerequisites
To complete this guide, you need:
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Roughly 15 minutes
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JDK 11+ installed with
JAVA_HOMEconfigured appropriately
Prepare WildFly Servers
Now, let’s configure two WildFly servers with embedded ActiveMQ Artemis brokers in a cluster. We’ll use the full-ha profile,
as it already contains most of the necessary settings and requires only minor modifications.
By default, the messaging cluster in WildFly uses JGroups, which relies on a multicast-based discovery mechanism to locate servers in the cluster. This allows the cluster to automatically discover and add new servers within the network. However, if multicast is not available or suitable for your environment, you can configure the messaging cluster to use alternative discovery mechanisms based on your specific requirements. This flexibility ensures that the cluster can be adapted to various network topologies and infrastructure setups.
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Note
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While the |
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Copy WildFly into two directories
wildfly-1andwildfly-2 -
Start
wildfly-1in afull-haprofile in admin-only mode:
./wildfly-1/bin/standalone.sh -c standalone-full-ha.xml --admin-only-
In a different terminal, connect to the server using the JBoss CLI:
./wildfly-1/bin/jboss-cli.sh -c-
Run the following CLI commands on
wildfly-1:
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Note
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In the following CLI script, replace |
# Change ActiveMQ Artemis cluster <password>
/subsystem=messaging-activemq/server=default:write-attribute(name=cluster-password, value=<password>)
# Rebalance inbound connections for MDBs when cluster topology changes
/subsystem=messaging-activemq/server=default/pooled-connection-factory=activemq-ra:write-attribute(name=rebalance-connections,value=true)
# Shutdown the server
shutdown-
Start
wildfly-2in afull-haprofile in admin-only mode (set port offset to 1000 to avoid port conflicts):
./wildfly-2/bin/standalone.sh -c standalone-full-ha.xml -Djboss.socket.binding.port-offset=1000 --admin-only-
In a different terminal, connect to the server using the JBoss CLI:
./wildfly-2/bin/jboss-cli.sh -c --controller=127.0.0.1:10990-
Run the following CLI commands on
wildfly-2:
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Note
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In the following CLI script, replace |
# Change ActiveMQ Artemis cluster <password>
/subsystem=messaging-activemq/server=default:write-attribute(name=cluster-password, value=<password>)
# Rebalance inbound connections for MDBs when cluster topology changes
/subsystem=messaging-activemq/server=default/pooled-connection-factory=activemq-ra:write-attribute(name=rebalance-connections,value=true)
# Shutdown the server
shutdownTesting and Verifying the Messaging Cluster
We’ll use the helloworld-mdb quickstart from WildFly
to test and verify the messaging cluster. This quickstart features a HelloWorldMDBServletClient servlet that sends messages
to the HELLOWORLDMDBQueue queue, and a HelloWorldQueueMDB MDB that consumes messages from this queue.
Start both WildFly servers, each in a separate terminal:
./wildfly-1/bin/standalone.sh -c standalone-full-ha.xml
./wildfly-2/bin/standalone.sh -c standalone-full-ha.xml -Djboss.socket.binding.port-offset=1000Check the server logs to verify it contains the following entry:
14:20:30,673 INFO [org.apache.activemq.artemis.core.server] (Thread-2 (ActiveMQ-server-org.apache.activemq.artemis.core.server.impl.ActiveMQServerImpl$6@33607b42)) AMQ221027: Bridge ClusterConnectionBridge ... is connectedThis log entry indicates that the cluster has been successfully formed.
You can build and deploy the helloworld-mdb quickstart by running:
git clone git@github.com:wildfly/quickstart.git
cd quickstart/helloworld-mdb
mvn clean package wildfly:deploy
mvn clean package wildfly:deploy -Dwildfly.port=10990At this point, open your web browser and navigate to http://localhost:8080/helloworld-mdb/. This will invoke the servlet
to send messages to the HelloWorldMDBServletClient queue on wildfly-1 server.
Check the server logs of both servers to ensure they contain entries similar to the following:
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14:54:32,439 INFO [class org.jboss.as.quickstarts.mdb.HelloWorldQueueMDB] (Thread-19 (ActiveMQ-client-global-threads)) Received Message from queue: This is message 2
14:54:32,447 INFO [class org.jboss.as.quickstarts.mdb.HelloWorldQueueMDB] (Thread-19 (ActiveMQ-client-global-threads)) Received Message from queue: This is message 4
...
----The presence of these log entries in the wildfly-2 server log confirms that messages were successfully load balanced from wildfly-1.
What’s Next?
With the ActiveMQ Artemis cluster in place, you can explore various strategies for server-side message and client load balancing. This flexibility allows you to optimize performance and reliability according to your specific needs.
Additionally, the setup of an ActiveMQ Artemis cluster is a prerequisite for implementing High Availability. For a comprehensive guide on configuring WildFly with a Messaging (ActiveMQ Artemis) Cluster and High Availability, refer to Configure WildFly with a Messaging (ActiveMQ Artemis) Cluster and High Availability.
