Configure throttle-limit as a parameter?

[bwawok]

Is there a good way to configure a <batch:tasklet>'s throttle-limit property as a run time job parameter? We are currently testing a job on different hardware, and we would like to try different settings for throttle-limit for each job, without having to rebuild our code.

The {jobParameters[] } syntax does not seem to work, but it could very well be my ignorance of how late binding is going on in Spring Batch...

[mminella]

My hunch (and this is getting into Spring Core stuff that I'm not 100% on how it works) is that that wouldn't be possible using the standard Spring Batch tags. What I think you would have to try (and I'm not even sure if this is still supported) is try to configure your tasklet the way Spring Batch 1.x did (as a bean instead with the <tasklet> tag). I'm not even sure that that will work, but it might work around the issue. Otherwise, I would think you should be able to inject it as a property file that you could package outside of your artifact.

[akorotenko]

I've also faced with this problem.
We are writing jobs configurator, so I prefer to set a lot of parameters by myself.

You can define StepFactoryBean

	<bean id="factoryBean" class="org.springframework.batch.core.step.item.FaultTolerantStepFactoryBean">
		<property name="transactionManager" ref="transactionManager" />
		<property name="jobRepository" ref="jobRepository" />
		<property name="startLimit" value="100" />
		<property name="commitInterval" value="10" />
		<property name="skipLimit" value="400" />
                <property name="taskExecutor" ref="asyncTaskExecutor" />
		<property name="listeners">
			<list>
				<ref bean="skipListener" />
				<ref bean="stepExecutionListener" />
			</list>
		</property>
		<property name="skippableExceptionClasses">
			<map>
	
					<entry key-ref="runtimeException" value="true" />
<!-- 				<entry key-ref="pathNotFoundException" value="true" /> -->
<!-- 				<entry key-ref="documentGenerationException" value="true" /> -->
			</map>
		</property>
	</bean>

then inject it... and all others beans what you need

......................................................
......................................................               
                factoryBean.setSkipLimit(jobDefinition.getSkipLimit());
		
		factoryBean.setCommitInterval(jobDefinition.getCommitInterval());
		factoryBean.setThrottleLimit(jobDefinition.getThrottleLimit());
		
		TaskletStep taskletStep = (TaskletStep) factoryBean.getObject();
		taskletStep.setName("Tasklet Step");
		
		job.addStep(taskletStep);

......................................................
......................................................

               jobLauncher.run(job, jobParametersBuilder.toJobParameters());

It's quite flexible approach. For instance you can also set taskExecutor programmatically and manipulate maxPoolSize, queueCapacity etc on-a-fly

IMHO, of course

[Ahado]

There is a simpler solution to this problem. The throttling is actually performed by the task Executor for the step - for concurrent processing this is normally a SimpleAsyncTaskExecutor. This is generally defined as a named bean in the config. Simply load this bean and set the concurrencyLimit explicitly.

Note that there is a warning in the class that changing unlimited (-1, default) to a concrete value at runtime messes up the concurrency counts. So put a concrete limit on the bean def in the config.