Issue with number of threads while using SimpleAsyncTaskExecutor

[kissen]

Hi,

We are currently using the SimpleAsyncTaskExecutor within our batch application whereby the concurrencyLimit is configurable using a job parameter as shown below:

<bean id="taskExecutor" class="org.springframework.core.task.SimpleAsyncTaskExecutor" scope="step">  
    	<!-->property name="concurrencyLimit" value="10"/--> 
    	<property name="concurrencyLimit" value="#{jobParameters[numberOfTreads]}"/>   
    </bean>

We have noticed odd thing while profiling the application in the sense that more that one thread has been seen running (up to 4 threads with limit set to 0)

Any explanation on this?

Thanks

[Dave Syer]

Any explanation on this?

A quick look at the source code for SimpleAsyncTaskExecutor confirms that concurrencyLimit=0 switches off the concurrency limit because isThrottleActive() checks for >0 (-1 is the default). I'm not sure what you expect to happen if you set the limit to 0 - it doesn't make a lot of sense, so you are lucky it does anything at all.