Tuesday, November 15, 2011

Standalone HornetQ and JBoss, part 2: making it work without embedded server

Rant mode off.

Actually it is not that bad. It is just so happened that HornetQ standalone ended up being last on the list of things I have tried. And it became the last straw.

In reality the biggest single WTF was not HornetQ but ActiveMQ acknowledging received messages despite timed out transaction. The biggest collection of WTFs in a single place was of course (and is, and probably will be forever) OracleAQ.

But back to configuring JBoss AS 6 to work with the standalone HornetQ.
  1. The most important thing is to use JBoss AS 6.1.0.Final and not 6.0. Details are here. This is something I already knew and it is not specific to the standalone configuration of HornetQ, but it is worth mentioning here anyway.

  2. JBoss will be configured to talk to the external standalone HornetQ. The embedded HornetQ will be removed. This is what I want to achieve. Yes, it is possible to go for the standalone HornetQ environment and still run the embedded HornetQ just in case. But I find it pointless. Note also that no new resource adapter is added to JBoss. Instead the configuration of the existing one is changed.

  3. Move JBOSS_HOME/server/<servername>/deploy/hornetq/jms-ds.xml to JBOSS_HOME/server/<servername>/deploy. This is where outbound connection factories are defined. The file will have to be changed, see below.

  4. Delete JBOSS_HOME/server/<servername>/deploy/hornetq directory. This is where the configuration of the embedded HornetQ lives.

  5. Delete JBOSS_HOME/server/<servername>/deployers/hornetq-deployers-jboss-beans.xml. This file specifies how HornetQ specific configuration files should be read to initialize embedded HornetQ server and its destination objects. No embedded HornetQ means no need to read these configuration files.

  6. Change the resource adapter configuration file: JBOSS_HOME/server/<servername>/deploy/jms-ra.rar/META-INF/ra.xml. This is actually documented here: Configuring the Incoming Adaptor or here: HORNETQ_HOME/examples/javaee/jca-remote/readme.html, section "configuring the incoming Adapter". Basically you need to change two RA properties:
    The transport type. Multiple connectors can be configured by using a comma separated list,
    i.e. org.hornetq.core.remoting.impl.invm.InVMConnectorFactory,org.hornetq.core.remoting.impl.invm.InVMConnectorFactory.
    <!-- <config-property-value>org.hornetq.core.remoting.impl.invm.InVMConnectorFactory</config-property-value> -->
    <description>The transport configuration. These values must be in the form of key=val;key=val;,
    if multiple connectors are used then each set must be separated by a comma i.e. host=host1;port=5445,host=host2;port=5446.
    Each set of params maps to the connector classname specified.
    <!-- <config-property-value>server-id=0</config-property-value> -->
    The incoming messages will be received from the standalone HornetQ server available at localhost:5445.

  7. Change the connection factory configuration file (jms-ds.xml copied to deploy directory at step 3 above). It is also documented Configuring the outgoing adaptor or here: HORNETQ_HOME/examples/javaee/jca-remote/readme.html, section "configuring the outgoing Adapter". This is what the resulting file looks like:
    <config-property name="SessionDefaultType" type="java.lang.String">javax.jms.Topic</config-property>
    <config-property name="ConnectorClassName" type="java.lang.String">org.hornetq.core.remoting.impl.netty.NettyConnectorFactory</config-property>
    <config-property name="ConnectionParameters" type="java.lang.String">host=;port=5445</config-property>

The situation now is still not complete because no destination objects are registered in JBoss JNDI. JBoss can be started but deploying an application that uses @Resource will still fail. The good thing: the embedded HornetQ is out of picture.

The remaining piece of configuration depends actually on how the application uses JMS. If the application contains some MDBs to receive messages from destinations, then it is possible to skip JNDI registration completely. Whether it is a good idea is another question. Just add something like this to the MDB code or the equivalent configuration to its deployment descriptor:
@MessageDriven(activationConfig = {
@ActivationConfigProperty(propertyName = "destinationType", propertyValue = "javax.jms.Queue"),
@ActivationConfigProperty(propertyName = "destination", propertyValue = "TestQueue"),
@ActivationConfigProperty(propertyName = "UseJNDI", propertyValue = "false"),

The key here is the property named "UseJNDI". The default value is true and the destination has to be registered in the JNDI. Setting the property to false skips JNDI lookup. After all, JNDI registration is just a bit more than a mapping from say "jms/hq/AQueue" JNDI name to the queue name ("TestQueue") known to the server. The HornetQ resource adapter will use "TestQueue" as the queue name in its communication with the server.

If the application needs that kind of indirection or if it sends messages and relies on @Resource injection line that:
@Resource(mappedName = "jms/hq/AQueue")
private Queue queue;
then some more configuration is needed. This configuration can be done at the server level so the destinations are available to all applications as soon as the server is started or at the application level. Note: I did not actually test the application level configuration. There might be initialization order problems: JNDI name must be available for injection but it is not yet there.

This is what is missing in HornetQ documentation. This and also the way to make it easier and less verbose:

Create a file named jboss-beans.xml in META-INF (or WEB-INF) directory of your application if you want to deploy the configuration with your application. Or create a file named <something meaningful>- jboss-beans.xml in JBOSS_HOME/server/<servername>/deploy. Copy the following to the file:
<?xml version="1.0" encoding="UTF-8"?>
<deployment xmlns="urn:jboss:bean-deployer:2.0">
<bean name="HQ_JNDIBindingService" class="org.jboss.naming.JNDIBindingService">
<property name="bindings">
<bean class="org.jboss.naming.JNDIBindings">
<property name="bindings">
<array elementClass="org.jboss.naming.JNDIBinding">
<bean class="org.jboss.naming.JNDIBinding">
<property name="name">jms/hq/AQueue</property>
<property name="value">
<!-- Use org.hornetq.jms.client.HornetQTopic for topic -->
<bean class="org.hornetq.jms.client.HornetQQueue">

<!-- You can add here more <bean class="org.jboss.naming.JNDIBinding"> definitions for other destinations -->


This configuration creates a JNDI entry under name "jms/hq/AQueue" and makes sure that is it the correct class (org.hornetq.jms.client.HornetQQueue which implements javax.jms.Queue). This entry represents a queue named "TestQueue" on a server. Note: "on a server". As I have mentioned in the previous post this object is just a mapping to the destination name and it comes alive only with the correct ConnectionFactory/ConnectorFactory.

That is it. Hey, HornetQ, was it difficult to document?

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