Preventing stopped or delayed agents in JBoss EAR deployments with an ActiveMQ resource adapter
Agents in a Pega EAR deployment on the JBoss Enterprise Application Platform (EAP) application server stop or delayed after a period of time. When you add a slow agent, you eventually see multiple agents failing to meet their service level agreements (SLAs) compared to system clock time, as shown in the following example.
Agents scheduling run status, General Information
Agents scheduling run status, SendCorr times
Agents scheduling run status, other agent times
Analysis indicates that HornetQ, the embedded Java Message Service (JMS) in JBoss, is the root cause of this problem. Messages sent to HornetQ do not invoke the Pega Message-Driven Bean (MDB) onMessage() method in a timely way.
Debugging HornetQ was rejected in favor of installing the ActiveMQ resource adapter on JBoss and configuring the Pega MDB to use ActiveMQ in place of HornetQ.
You can choose to configure ActiveMQ to run in one of two ways:
- As a standalone broker
- As an embedded broker inside JBoss
This article explains how to install and configure the ActiveMQ resource adapter for JBoss Redhat EAP 6.1.
Install the ActiveMQ resource adapter
Configure the ActiveMQ resource adapter
Download and start the ActiveMQ broker (standalone broker only)
Install the ActiveMQ resource adapter
Installing the ActiveMQ resource adapter is not done in the standard way. Therefore, it is best to install it using the JBoss Administrator Console.
- From the Apache repository, https://repository.apache.org/content/repositories/releases/org/apache/activemq/activemq-rar/5.9.0/, download the ActiveMQ resource adapter, activemq-rar-5.9.0.rar.
- Inside the JBoss deployment, add this module:
modules\system\layers\base\org\apache\activemq\main - Extract the ActiveMQ resource adapter that you downloaded in Step1 to the folder \activemq\main.
JBoss EAP 6.1 ActiveMQ main folder - Open the file main\META-INF ra.xml and search for the comment
<!-- NOTE disable the following property if you do not wish to deploy an embedded broker →- If you are configuring ActiveMQ as a standalone broker, remove the property.
- If you are configuring ActiveMQ as an embedded broker, keep the property.
- In the \activemq\main folder, create the file module.xml and specify it with the content shown after this screen:
JBoss EAP 6.1 \activemq\main\module.xml
<?xml version="1.0" encoding="UTF-8"?>
<module xmlns="urn:jboss:module:1.1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" name="org.apache.activemq">
<resources>
<resource-root path="." />
<resource-root path="activemq-broker-5.9.0.jar" />
<resource-root path="activemq-client-5.9.0.jar" />
<resource-root path="activemq-jms-pool-5.9.0.jar" />
<resource-root path="activemq-kahadb-store-5.9.0.jar" />
<resource-root path="activemq-openwire-legacy-5.9.0.jar" />
<resource-root path="activemq-pool-5.9.0.jar" />
<resource-root path="activemq-protobuf-1.1.jar" />
<resource-root path="activemq-ra-5.9.0.jar" />
<resource-root path="activemq-spring-5.9.0.jar" />
<resource-root path="aopalliance-1.0.jar" />
<resource-root path="commons-pool-1.6.jar" />
<resource-root path="commons-logging-1.1.3.jar" />
<resource-root path="hawtbuf-1.9.jar" />
<resource-root path="spring-aop-3.2.4.RELEASE.jar" />
<resource-root path="spring-beans-3.2.4.RELEASE.jar" />
<resource-root path="spring-context-3.2.4.RELEASE.jar" />
<resource-root path="spring-core-3.2.4.RELEASE.jar" />
<resource-root path="spring-expression-3.2.4.RELEASE.jar" />
<resource-root path="xbean-spring-3.14.jar" />
</resources>
<exports>
<exclude path="org/springframework/**" />
<exclude path="org/apache/xbean/**" />
<exclude path="org/apache/commons/**" />
<exclude path="org/aopalliance/**" />
<exclude path="org/fusesource/**" />
</exports>
<dependencies>
<module name="javax.api" />
<module name="org.slf4j" />
<module name="javax.resource.api" />
<module name="javax.jms.api" />
<module name="javax.management.j2ee.api" />
</dependencies>
</module>
Configure the ActiveMQ resource adapter
Modify the file Standalone-full.xml
Ensure that the MDBs use the ActiveMQ resource adapter
Modify the prpc_j2ee14_jboss61JBM preconfigured JMS topic
Modify the file Standalone-full.xml
Update the resource adapter subsystem in the Standalone-full.xml configuration file by adding the following parameters in the resource-adapter subsystem, depending on whether you are configuring Active MQ as a standalone broker or embedded broker.
Standalone broker
For a standalone broker, specify the ServerURL as tcp://localhost:61616.
<subsystem xmlns="urn:jboss:domain:resource-adapters:1.1">
<resource-adapters>
<resource-adapter id="org.apache.activemq.ra">
<module slot="main" id="org.apache.activemq"/>
<transaction-support>NoTransaction</transaction-support>
<config-property name="ServerUrl">
tcp://localhost:61616
</config-property>
<connection-definitions>
<connection-definition class-name="org.apache.activemq.ra.ActiveMQManagedConnectionFactory" jndi-name="java:/jms/PRAsyncTCF" enabled="true" pool-name="ActiveMQConnectionFactoryPool">
</connection-definition>
</connection-definitions>
<admin-objects>
<admin-object class-name="org.apache.activemq.command.ActiveMQTopic" jndi-name="java:/topic/jms/PRAsyncTopic" use-java-context="true" pool-name="PRAsyncTopic">
<config-property name="PhysicalName">
java:/topic/jms/PRAsyncTopic
</config-property>
</admin-object>
</admin-objects>
</resource-adapter>
</resource-adapters>
</subsystem>
Embedded broker
For an embedded broker, specify the ServerURL as vm://localhost.
<subsystem xmlns="urn:jboss:domain:resource-adapters:1.1">
<resource-adapters>
<resource-adapter id="org.apache.activemq.ra">
<module slot="main" id="org.apache.activemq"/>
<transaction-support>NoTransaction</transaction-support>
<config-property name="ServerUrl">
vm://localhost
</config-property>
<connection-definitions>
<connection-definition class-name="org.apache.activemq.ra.ActiveMQManagedConnectionFactory" jndi-name="java:/jms/PRAsyncTCF" enabled="true" pool-name="ActiveMQConnectionFactoryPool">
</connection-definition>
</connection-definitions>
<admin-objects>
<admin-object class-name="org.apache.activemq.command.ActiveMQTopic" jndi-name="java:/topic/jms/PRAsyncTopic" use-java-context="true" pool-name="PRAsyncTopic">
<config-property name="PhysicalName">
java:/topic/jms/PRAsyncTopic
</config-property>
</admin-object>
</admin-objects>
</resource-adapter>
</resource-adapters>
</subsystem>
Ensure that the MDBs use the ActiveMQ resource adapter
Locate the tag <mdb> and update it as shown here:
<mdb>
<resource-adapter-ref resource-adapter-name="org.apache.activemq.ra"/>
<bean-instance-pool-ref pool-name="mdb-strict-max-pool"/>
</mdb>
Modify the prpc_j2ee14_jboss61JBM preconfigured JMS topic
Open the file prpc_j2ee14_jboss61JBM\META-INF\hornetq-jms.xml and comment out or remove the <hornetq-server> tags as shown here:
<?xml version="1.0" encoding="UTF-8"?>
<messaging-deployment xmlns="urn:jboss:messaging-deployment:1.0">
<!— (remove the hornetq-server tags and everything enclosed by them)
<hornetq-server>
<jms-destinations>
<jms-topic name="PegaAsyncTopic">
<entry name="topic/jms/PRAsyncTopic"/>
</jms-topic>
</jms-destinations>
</hornetq-server>
-- >
</messaging-deployment>
Download and start the ActiveMQ broker (standalone broker only)
If you are configuring the ActiveMQ broker as an embedded broker, skip this section. You can start ActiveMQ and deploy the modified Pega 7 EAR file.
If you are configuring the ActiveMQ broker as a standalone broker, complete the following steps:
- Download the ActiveMQ broker: http://activemq.apache.org/activemq-590-release.html
- Start it with the default port.
File folder apache_activemq_590_bin - Log in as Administrator and create a topic with the same name as the physical name that you specified in the resource adapter subsystem, Configure the ActiveMQ resource adapter, Modify the file Standalone-full.xml.
ActiveMQ topic PRAsynchTopic - You are all set! Start ActiveMQ and deploy the modified Pega 7 EAR file.