javax.security.auth.login.FailedLoginException: user name is null in Fabric client with clustered ActiveMQ

Issue

• We create a cluster of AMQ brokers using fabric:mq-create, and then connect to them using a bundle that utilizes a Camel Route.
• We are using the discovery url - discovery:(fabric:mymq), and setting up the ActiveMQXAConnectionFactory as below:

<bean id="activemq-factory" class="org.apache.activemq.ActiveMQXAConnectionFactory">
        <property name="brokerURL" value="${amq.broker.url}"></property>
        <property name="userName" value="${amq.broker.username}"></property>
        <property name="password" value="${amq.broker.password}"></property>
    </bean>

and a ResourceManager as:

<bean id="resourceManager" class="org.apache.activemq.pool.ActiveMQResourceManager"
          init-method="recoverResource">
        <property name="transactionManager" ref="recoverableTxManager"></property>
        <property name="connectionFactory" ref="activemq-jms-xa-connection-factory"></property>
        <property name="resourceName" value="activemq.default"></property>
    </bean>

• When the bundle gets deployed, it keeps on giving me an error with the stack trace shown below. What user name / password is it missing? How can we fix this?

javax.transaction.SystemException: Failed to create ConnectionAndWrapperNamedXAResource, User name [null] or password is invalid.
  at org.apache.activemq.jms.pool.GenericResourceManager$Recovery$1.getNamedXAResource(GenericResourceManager.java:161)[org.apache.activemq:activemq-osgi:5.9.0.redhat-610379]
  at org.apache.geronimo.transaction.manager.RecoverTask.run(RecoverTask.java:49)[org.apache.aries.transaction:org.apache.aries.transaction.manager:1.0.1.redhat-610379]
  at org.apache.geronimo.transaction.manager.ExponentialtIntervalRetryScheduler$TaskWrapper.run(ExponentialtIntervalRetryScheduler.java:50)[org.apache.aries.transaction:org.apache.aries.transaction.manager:1.0.1.redhat-610379]
  at java.util.TimerThread.mainLoop(Timer.java:555)[:1.7.0_51]
  at java.util.TimerThread.run(Timer.java:505)[:1.7.0_51]
Caused by: javax.jms.JMSSecurityException: User name [null] or password is invalid.
  at org.apache.activemq.util.JMSExceptionSupport.create(JMSExceptionSupport.java:52)[org.apache.activemq:activemq-osgi:5.9.0.redhat-610379]
  at org.apache.activemq.ActiveMQConnection.syncSendPacket(ActiveMQConnection.java:1408)[org.apache.activemq:activemq-osgi:5.9.0.redhat-610379]
  at org.apache.activemq.ActiveMQConnection.ensureConnectionInfoSent(ActiveMQConnection.java:1513)[org.apache.activemq:activemq-osgi:5.9.0.redhat-610379]
  at org.apache.activemq.ActiveMQXAConnection.createSession(ActiveMQXAConnection.java:74)[org.apache.activemq:activemq-osgi:5.9.0.redhat-610379]
  at org.apache.activemq.ActiveMQXAConnection.createXASession(ActiveMQXAConnection.java:61)[org.apache.activemq:activemq-osgi:5.9.0.redhat-610379]
  at org.apache.activemq.jms.pool.GenericResourceManager$Recovery$1.getNamedXAResource(GenericResourceManager.java:155)[org.apache.activemq:activemq-osgi:5.9.0.redhat-610379]
... 4 more
Caused by: java.lang.SecurityException: User name [null] or password is invalid.
  at org.apache.activemq.security.JaasAuthenticationBroker.addConnection(JaasAuthenticationBroker.java:80)
  at org.apache.activemq.broker.MutableBrokerFilter.addConnection(MutableBrokerFilter.java:97)
  at org.apache.activemq.broker.TransportConnection.processAddConnection(TransportConnection.java:764)
  at org.apache.activemq.broker.jmx.ManagedTransportConnection.processAddConnection(ManagedTransportConnection.java:79)
  at org.apache.activemq.command.ConnectionInfo.visit(ConnectionInfo.java:139)
  at org.apache.activemq.broker.TransportConnection.service(TransportConnection.java:294)
  at org.apache.activemq.broker.TransportConnection$1.onCommand(TransportConnection.java:148)
  at org.apache.activemq.transport.MutexTransport.onCommand(MutexTransport.java:50)
  at org.apache.activemq.transport.WireFormatNegotiator.onCommand(WireFormatNegotiator.java:113)
  at org.apache.activemq.transport.AbstractInactivityMonitor.onCommand(AbstractInactivityMonitor.java:270)
  at org.apache.activemq.transport.TransportSupport.doConsume(TransportSupport.java:83)
  at org.apache.activemq.transport.tcp.TcpTransport.doRun(TcpTransport.java:214)[org.apache.activemq:activemq-osgi:5.9.0.redhat-610379]
  at org.apache.activemq.transport.tcp.TcpTransport.run(TcpTransport.java:196)[org.apache.activemq:activemq-osgi:5.9.0.redhat-610379]
  at java.lang.Thread.run(Thread.java:744)[:1.7.0_51]
Caused by: javax.security.auth.login.FailedLoginException: user name is null
  at io.fabric8.jaas.ZookeeperLoginModule.login(ZookeeperLoginModule.java:106)
  at org.apache.karaf.jaas.boot.ProxyLoginModule.login(ProxyLoginModule.java:83)[karaf-jaas-boot.jar:]
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)[:1.7.0_51]
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)[:1.7.0_51]
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)[:1.7.0_51]
  at java.lang.reflect.Method.invoke(Method.java:606)[:1.7.0_51]
  at javax.security.auth.login.LoginContext.invoke(LoginContext.java:775)
  at javax.security.auth.login.LoginContext.access$000(LoginContext.java:205)
  at javax.security.auth.login.LoginContext$5.run(LoginContext.java:697)
  at javax.security.auth.login.LoginContext$5.run(LoginContext.java:695)
  at java.security.AccessController.doPrivileged(Native Method)[:1.7.0_51]
  at javax.security.auth.login.LoginContext.invokePriv(LoginContext.java:694)
  at javax.security.auth.login.LoginContext.login(LoginContext.java:602)
  at org.apache.activemq.security.JaasAuthenticationBroker.addConnection(JaasAuthenticationBroker.java:73)
... 13 mor