What will happen if a SEDA queue is full ?

[smxnoob]

Hi,

I want to know how does a SEDA queue deal with incoming message when it is overloaded or full ?

Regards,

Servicemix Noob ?:|

[martinmurphy]

The SEDA queue is implemented using java.util.concurrent classes, in particular the ThreadPoolExecutor. Each component has a default intial thread pool of four and a queue size of 1024. The maximum size for the thread pool is unlimited, so by default you should never end up with an overloaded queue.

That said, FUSE ESB does over-ride the properties of the default config in conf/servicemix.xml

<sm:executorFactory>
  <bean class="org.apache.servicemix.executors.impl.ExecutorFactoryImpl">
    <property name="defaultConfig">
        <bean class="org.apache.servicemix.executors.impl.ExecutorConfig">
          <property name="corePoolSize" value="${servicemix.corePoolSize}"></property>
          <property name="maximumPoolSize" value="${servicemix.maximumPoolSize}"></property>
          <property name="queueSize" value="${servicemix.queueSize}"></property>
        </bean>
    </property>
  </bean>
</sm:executorFactory>

This picks up it's placeholder properties from the servicemix.properties file:

servicemix.corePoolSize    = 16
servicemix.maximumPoolSize = 32
servicemix.queueSize       = 256

So in a standard FUSE ESB installation the max thread pool is 32 and the queue is 256.

If a message fails to be enqueued in the thread pool a javax.jbi.messaging.MessagingException will be thrown. This then has to be handled by the calling producer that placed the message exchange on the NMR.

Hope that helps