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You can also check out a suite of camel-based services in the Fedora Camel Toolbox.

Setup Fedora to Talk to External ActiveMQ

Download the latest ActiveMQ 5 Linux .tar.gz from https://activemq.apache.org/components/classic/download

  1. Unpack the file and move it under /opt
  2. Create a symlink from the unpacked directory to /opt/activemq
  3. Create an activemq user: sudo adduser --system --no-create-home activemq
  4. Change ownership: sudo chown -R activemq:activemq /opt/activemq/
  5. Set up the unit file in /usr/lib/systemd/system/activemq.service:


Code Block
[Unit]

Description=Apache ActiveMQ
After=network-online.target

[Service]

Type=forking
WorkingDirectory=/opt/activemq/bin
ExecStart=/opt/activemq/bin/activemq start
ExecStop=/opt/activemq/bin/activemq stop
Restart=on-abort
User=activemq
Group=activemq

[Install]
WantedBy=multi-user.target


  1. Edit /opt/activemq/conf/activemq.xml and change port numbers in the transportConnectors section (to avoid conflicts with Fedora’s built-in ActiveMQ):
    1. 61616 -> 41616
    2. 61613 -> 41613
  2. Start and enable the service: sudo systemctl enable activemq ; sudo systemctl start activemq
  3. Edit /opt/fedora/fcrepo.properties and add some properties to customize the configuration and file location for the internal Fedora ActiveMQ:
    1. fcrepo.activemq.configuration=file:///opt/fedora/config/activemq.xml
    2. fcrepo.activemq.directory=/opt/fedora/queue
  4. Create /opt/fedora/config/activemq.xml (this is the default Fedora ActiveMQ configuration with a fedora_bridge network connector added to forward messages to port 41616):


Code Block
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
    http://activemq.apache.org/schema/core http://activemq.apache.org/schema/core/activemq-core.xsd">

    <context:property-placeholder/>
    <bean id="activeMqDirectory" class="java.lang.String">
        <constructor-arg value="#{fedoraPropsConfig.activeMqDirectory}"/>
    </bean>
    <!--
        The <broker> element is used to configure the ActiveMQ broker.
    -->
    <broker xmlns="http://activemq.apache.org/schema/core" brokerName="localhost">
  <networkConnectors>
    <networkConnector name="fedora_bridge" dynamicOnly="true" uri="static:(tcp://localhost:41616)">
      <dynamicallyIncludedDestinations>
        <topic physicalName="fedora"/>
        <queue physicalName="fedora"/>
      </dynamicallyIncludedDestinations>
    </networkConnector>
  </networkConnectors>
        <!--
            For better performances use VM cursor and small memory limit.
            For more information, see:
            http://activemq.apache.org/message-cursors.html
            Also, if your producer is "hanging", it's probably due to producer flow control.
            For more information, see:
            http://activemq.apache.org/producer-flow-control.html
        -->
        <destinationPolicy>
            <policyMap>
                <policyEntries>
                    <policyEntry topic=">" producerFlowControl="true">
                        <!-- The constantPendingMessageLimitStrategy is used to prevent
                         slow topic consumers to block producers and affect other consumers
                         by limiting the number of messages that are retained
                         For more information, see:
                         http://activemq.apache.org/slow-consumer-handling.html
                    -->
                        <pendingMessageLimitStrategy>
                            <constantPendingMessageLimitStrategy limit="1000"/>
                        </pendingMessageLimitStrategy>
                    </policyEntry>
                    <policyEntry queue=">" producerFlowControl="true" memoryLimit="1mb">
                        <!-- Use VM cursor for better latency
                       For more information, see:
                       http://activemq.apache.org/message-cursors.html
                  <pendingQueuePolicy>
                    <vmQueueCursor/>
                  </pendingQueuePolicy>
                  -->
                    </policyEntry>
                </policyEntries>
            </policyMap>
        </destinationPolicy>
        <!--
            The managementContext is used to configure how ActiveMQ is exposed in
            JMX. By default, ActiveMQ uses the MBean server that is started by
            the JVM. For more information, see:
            http://activemq.apache.org/jmx.html
        -->
        <managementContext>
            <managementContext createConnector="false"/>
        </managementContext>
        <!--
            Configure message persistence for the broker. The default persistence
            mechanism is the KahaDB store (identified by the kahaDB tag).
            For more information, see:
            http://activemq.apache.org/persistence.html
        -->
        <persistenceAdapter>
            <kahaDB directory="#activeMqDirectory"/>
        </persistenceAdapter>
        <!--
            The systemUsage controls the maximum amount of space the broker will
            use before slowing down producers. For more information, see:
            http://activemq.apache.org/producer-flow-control.html
            If using ActiveMQ embedded - the following limits could safely be used:
            -->
        <systemUsage>
            <systemUsage>
                <memoryUsage>
                    <memoryUsage limit="20 mb"/>
                </memoryUsage>
                <storeUsage>
                    <storeUsage limit="1 gb"/>
                </storeUsage>
                <tempUsage>
                    <tempUsage limit="100 mb"/>
                </tempUsage>
            </systemUsage>
        </systemUsage>
        <!--
            The transport connectors expose ActiveMQ over a given protocol to
            clients and other brokers. For more information, see:
            http://activemq.apache.org/configuring-transports.html
        -->
        <transportConnectors>
            <!-- DOS protection, limit concurrent connections to 1000 and frame size to 100MB -->
            <transportConnector name="openwire"
                uri="tcp://0.0.0.0:#{fedoraPropsConfig.jmsPort}?maximumConnections=1000&amp;wireformat.maxFrameSize=104857600"
            />
            <transportConnector name="stomp"
                                uri="stomp://0.0.0.0:#{fedoraPropsConfig.stompPort}"/>
        </transportConnectors>
        <!-- destroy the spring context on shutdown to stop jetty -->
        <shutdownHooks>
            <bean xmlns="http://www.springframework.org/schema/beans"
                class="org.apache.activemq.hooks.SpringContextHook"/>
        </shutdownHooks>
    </broker>
    <!--
        Enable web consoles, REST and Ajax APIs and demos
        Take a look at ${ACTIVEMQ_HOME}/conf/jetty.xml for more details
    <import resource="jetty.xml"/>
    -->
</beans>


  1. Reconfigure Camel Toolbox by editing /opt/fedora/config/fcrepo-camel-toolbox.properties and adding:
    1. jms.brokerUrl=tcp://localhost:41616
  2. Restart Camel Toolbox: sudo systemctl restart cameltoolbox