ActiveMQ set properties with startup parameters - activemq

Question

Is there a way to set up some properties defined in activemq.xml (such as the shared storage) as startup parameters ?
<kahaDB directory="${data}/kahadb"/>
Running amq with -Dparam=value does not seem to work

Answer 1

I find it weird that this doesn't work for you, for example we are currently using the following Broker configuration
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:amq="http://activemq.apache.org/schema/core" 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://activemq.apache.org/schema/core http://activemq.apache.org/schema/core/activemq-core.xsd">
<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="systemPropertiesModeName" value="SYSTEM_PROPERTIES_MODE_OVERRIDE" />
<property name="ignoreResourceNotFound" value="true" />
<property name="ignoreUnresolvablePlaceholders" value="true" />
<property name="locations">
<list>
<value>classpath:activemq.properties</value>
<value>file:///${user.home}/activemq.properties</value>
<value>file:///#{systemProperties['activemq.properties']}</value>
</list>
</property>
</bean>
<broker useJmx="${activemq.expose.jmx}" persistent="false"
brokerName="${activemq.brokerName}"
xmlns="http://activemq.apache.org/schema/core">
<destinationPolicy>
<policyMap>
<policyEntries>
<policyEntry queue=">" enableAudit="false">
<networkBridgeFilterFactory>
<conditionalNetworkBridgeFilterFactory replayWhenNoConsumers="true"/>
</networkBridgeFilterFactory>
</policyEntry>
</policyEntries>
</policyMap>
</destinationPolicy>
<systemUsage>
<systemUsage>
<memoryUsage>
<memoryUsage limit="${activemq.memoryUsage}" />
</memoryUsage>
<tempUsage>
<tempUsage limit="${activemq.tempUsage}" />
</tempUsage>
</systemUsage>
</systemUsage>
<networkConnectors>
<networkConnector
name="queues"
uri="static:(${activemq.otherBrokers})"
networkTTL="3"
decreaseNetworkConsumerPriority="true"
conduitSubscriptions="false" >
<excludedDestinations>
<topic physicalName=">" />
</excludedDestinations>
</networkConnector>
<networkConnector
name="topics"
uri="static:(${activemq.otherBrokers})"
networkTTL="3"
decreaseNetworkConsumerPriority="true"
conduitSubscriptions="true" >
<excludedDestinations>
<queue physicalName=">" />
</excludedDestinations>
</networkConnector>
</networkConnectors>
<transportConnectors>
<!-- expose a TCP transport for clients to use -->
<transportConnector
uri="${activemq.protocol}${activemq.host}:${activemq.tcp.port}"
updateClusterClients="true"
rebalanceClusterClients="true" />
<transportConnector
uri="${activemq.websocket.protocol}${activemq.websocket.host}:${activemq.websocket.port}"
updateClusterClients="true"
rebalanceClusterClients="true" />
</transportConnectors>
</broker>
</beans>
Here normally the properties are read from the given properties file, however I have often used direct -D JMV system properties to overrule those from the properties file for some tests and never encountered any issues. I guess you could try the slighly more complex syntax of #{systemProperties['property.name']} to specifically set that a given property is a system property and not from a placeholder.
One last Point: which version of ActiveMQ are you using and which version of spring is this version using? I think the whole placeholder syntax was added somewhere around spring 3.1, so really quite some time ago, but this is the only reason I could imagine why this isn't working for you.