Why does spring task scheduler wait for previous task to finish?

Question

I have the following task scheduler setup:

<bean id="Task" class="foo.bar.Task" />

<bean id="TaskScheduler"
  class="org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler">
    <property name="waitForTasksToCompleteOnShutdown" value="true" />
    <property name="poolSize" value="1000" />
</bean>

<task:scheduled-tasks scheduler="TaskScheduler">
  <task:scheduled ref="Task" method="run" cron="*/5 * * * * *" />
</task:scheduled-tasks>

The Task just prints a line and sleeps for 10 seconds. With this setup, my expectation was that the task would run every 5 seconds, regardless of whether the previous task had finished it's execution (ie stopped sleeping). But that's not the case, the task runs once ever 15 seconds (the sleep time and then the next time the cron is hit).

How can I configure this so that the task runs every 5 seconds regardless of whether the previous execution finished?

Answer 1

In you run method put @Async anotation and see

   @Async
   public void run{

   }

or you can

Try out this

<bean id="schedulerTask"
       class="org.springframework.scheduling.timer.MethodInvokingTimerTaskFactoryBean">
    <property name="mytaskClass" ref="mytaskClass" />
    <property name="targetMethod" value="fooMethod" />
</bean>

<bean id="mytaskClass" class="foo.bar.Task" />

<bean id="timerTask" class="org.springframework.scheduling.timer.ScheduledTimerTask">
    <property name="timerTask" ref="schedulerTask" />
    <property name="delay" value="10" />
    <property name="period" value="5000" />
</bean>

<bean class="org.springframework.scheduling.timer.TimerFactoryBean">
    <property name="scheduledTimerTasks">
        <list>
            <ref local="timerTask" />
        </list>
    </property>
</bean>

Then Your class

 package foo.bar;

 public class Task{

  public void fooMethod(){
  // do task
 }

}

Added as per the request

   <!-- Thread pool related configurations  -->
   <bean name="workerThread" class="foo.WorkerThread"/>

  <bean name="managerThread" class="foo.ManagerThread" >
     <constructor-arg type="org.springframework.core.task.TaskExecutor" ref="taskExecutor" />
     <constructor-arg type="foo.process.WorkerThread" ref="workerThread"/>
   </bean>

   <bean id="taskExecutor" class="org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor" >
 <property name="corePoolSize" value="5" />
 <property name="maxPoolSize" value="30" />
 <property name="queueCapacity" value="100" />
</bean>
<!-- End Thread pool related configurations  -->

ManagerThread.java

public class ManagerThread {

private  TaskExecutor taskExecutor=null;
private  WorkerThread workerThread=null;


/**
 * @param taskExecutor
 * @param workerThread
 */
public ManagerThread(final TaskExecutor taskExecutor,final WorkerThread workerThread) {

    this.taskExecutor = taskExecutor;
    this.workerThread = workerThread;
}  


/**
 * Create a new thread and execte the requests
 * @param parameter
 */
 public synchronized void  fire(final Object parameter) {
    taskExecutor.execute( new Runnable() {
         public void run() {
             workerThread.execute( parameter );
         }
    });
  }

WorkerThread.java

@Component
public class WorkerThread {




public void execute(final Object request) {

     // do the job
    }

}

You could customize this as per your requirement