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<section xmlns="http://docbook.org/ns/docbook" version="5.0" xml:id="Java-Broker-Runtime-Close-Connection-When-No-Route">
  <title>Closing client connections on unroutable mandatory messages</title>

  <section xml:id="Java-Broker-Runtime-Close-Connection-When-No-Route-Summary">
  <title>Summary</title>
    <para>
        Due to asynchronous nature of AMQP 0-8/0-9/0-9-1 protocols sending a message with a routing key for which no queue binding exist results
        in either message being bounced back (if it is mandatory or immediate) or discarded on broker side otherwise.
    </para>
    <para>
        When a 'mandatory' message is returned back, the Apache Qpid JMS client for AMQP 0-9-1/0-10 conveys this by delivering
        an <emphasis>AMQNoRouteException</emphasis> through the configured ExceptionListener on the Connection.
        This does not cause channel or connection closure, however it requires a special exception handling
        on client side in order to deal with <emphasis>AMQNoRouteExceptions</emphasis>.
        This could potentially be a problem when using various messaging frameworks (e.g. Mule)
        as they usually close the connection on receiving any JMSException.
    </para>
    <para>
        In order to simplify application handling of scenarios where 'mandatory' messages
        are being sent to queues which do not actually exist, the Apache Qpid Broker for Java can be configured such that
        it will respond to this situation by closing the connection
        rather than returning the unroutable message to the client as it normally should.
        From the application perspective, this will result in failure of synchronous operations in progress such as a session commit() call.
    </para>
    <note>
        <para>This feature affects only transacted sessions.</para>
        <para>
            The Apache Qpid JMS client for AMQP 0-9-1/0-10 sends 'mandatory' messages when using Queue destinations
            and 'non-mandatory' messages when using Topic destinations.
        </para>
    </note>
  </section>
  <section xml:id="Java-Broker-Runtime-Close-Connection-When-No-Route-Configuration">
    <title>Configuring <emphasis>closeWhenNoRoute</emphasis></title>
    <para>
        The Broker attribute <emphasis>closeWhenNoRoute</emphasis> can be set to specify this feature on broker side.
        By default, it is turned on. Setting <emphasis>closeWhenNoRoute</emphasis> to <emphasis>false</emphasis> switches it off.
    </para>
    <para>
        Setting the <emphasis>closeWhenNoRoute</emphasis> in the JMS client connection URL can override the broker configuration
        on a connection specific basis, for example :
    </para>
    <example>
        <title>Disable feature to close connection on unroutable messages with client URL</title>
        <screen>
amqp://guest:guest@clientid/?brokerlist='tcp://localhost:5672'&amp;closeWhenNoRoute='false'</screen>
    </example>
    <para>
       If no value is specified on the client the broker setting will be used. If client setting is specified then it will take precedence
       over the broker-wide configuration. If the client specifies and broker does not support this feature the warning will be logged.
    </para>
    </section>
</section>