Is it safe using Spring Integration in web application from threading perspective ?

[kouhei.toki]

Hi,

I consider using Spring Integration in web application.

But, I am worrying that creating thread (like Poller) by application in web container harm ap server's resource management.

How Spring Integration manage thread ?
Is it safe using Spring Integration in web application from threading perspective ?

Thanks.

[Gary Russell]

Spring provides abstractions for that; see WorkManagerTaskExecutor and TimerManagerTaskScheduler...

http://static.springsource.org/sprin...cheduling.html

Simply use a TimerManagerTaskScheduler (for pollers) as described here...

http://static.springsource.org/sprin...-taskscheduler

...and use a WorkManagerTaskExecutor for any element that needs a TaskExecutor for asynchronous operations.

[kouhei.toki]

Thank you for reply !

I tryed to use WorkManagerTaskExecutor for JMS inbound message handling,
but I can't see my expected behavior.

I declare WorkManagerTaskExecutor and message-driven-channel-adapter below.

    <bean id="taskExecutor" class="org.springframework.scheduling.commonj.WorkManagerTaskExecutor">
      <property name="workManagerName" value="java:comp/env/wm/MyWorkManager" />
    </bean>
    <jms:message-driven-channel-adapter
        id="inboundAdapter" 
        channel="channel2" 
        destination-name="sampleQueue" 
        max-concurrent-consumers="30"/>

And, I set ap server's WorkManager max threads to 5 (I use myFoo commonJ with Tomcat).

So, my expected behavior is jms consumer concurrent thread limits by 5 (becase ap server's max thread is 5).
But, fact is conurrent 30 threads naming "org.springframework.jms.listener.DefaultMessageLi stenerContainer" arrive.

Is my expectation (concurrent thread limt by 5) wrong ?
Or my setting is insufficient ?

Thanks.

[Gary Russell]

You need to tell the adapter's message listener container to use your configured task executor; this is not directly available on the adapter using the namespace.

Declare a bean of type DefaultMessageListenerContainer, set the taskExecutor property (and the others such as concurrency), and provide it to the adapter using the 'container' attribute.

JavaDoc for DMLC.setTaskExecutor...

	/**
	 * Set the Spring {@code TaskExecutor} to use for running the listener threads.
	 * <p>Default is a {@link org.springframework.core.task.SimpleAsyncTaskExecutor},
	 * starting up a number of new threads, according to the specified number
	 * of concurrent consumers.
	 * <p>Specify an alternative {@code TaskExecutor} for integration with an existing
	 * thread pool. Note that this really only adds value if the threads are
	 * managed in a specific fashion, for example within a J2EE environment.
	 * A plain thread pool does not add much value, as this listener container
	 * will occupy a number of threads for its entire lifetime.
	 * @see #setConcurrentConsumers
	 * @see org.springframework.core.task.SimpleAsyncTaskExecutor
	 * @see org.springframework.scheduling.commonj.WorkManagerTaskExecutor
	 */
	public void setTaskExecutor(Executor taskExecutor) {
		this.taskExecutor = taskExecutor;
	}

[kouhei.toki]

I see, I changed my bean definition to...

    <bean id="sampleQueueListenerContainer" class="org.springframework.jms.listener.DefaultMessageListenerContainer">
        <property name="taskExecutor" ref="taskExecutor"/>
        <property name="connectionFactory" ref="connectionFactory"/>
        <property name="destinationName" value="sampleQueue"/>
    </bean>
    <jms:message-driven-channel-adapter
        id="inboundAdapter" 
        channel="channel2" 
        container="sampleQueueListenerContainer"/>

I tried, and it seems to use ap server's WorkManager.

Thank you for your kindness.