redstream » Quartz http://www.redstream.nl Pragmatic Integrators Fri, 27 Jan 2012 19:31:59 +0000 en hourly 1 Weird Quartz scheduler behaviour http://www.redstream.nl/2007/07/25/weird-quartz-scheduler-behaviour/ http://www.redstream.nl/2007/07/25/weird-quartz-scheduler-behaviour/#comments Wed, 25 Jul 2007 05:54:44 +0000 Pascal Alma http://www.pascalalma.net/?p=55 Continue reading →]]>

As I posted before here I am using Quartz scheduler to schedule some batch jobs. It seemed to work fine but now while we were testing our application it appeared Quartz was showing some weird behaviour. I have scheduled 3 jobs, each with it’s own trigger in one scheduler. However, 2 of the jobs are only triggered if the trigger of other remaining job has been fired before.
Of course I checked my configuration multiple times but I couldn’t find something wrong with it. After lots of testing and debugging I solved the issue by replacing the rescheduleJob() command with a simple deleteJob() and scheduleJob().

Here is the relevant original piece of code:

1
2
3
4
5

if (job == null) {
    nextRun = scheduler.scheduleJob(trigger.getJobDetail(), trigger);
} else {
    nextRun = scheduler.rescheduleJob(trigger.getFullName(), trigger.getGroup(), trigger);
}

After replacing this code with the next piece it worked fine again, although I cannot explain why….

1
2
3
4
5
6

if (job == null) {
    nextRun = scheduler.scheduleJob(trigger.getJobDetail(), trigger);
} else {
    scheduler.deleteJob(trigger.getJobDetail().getName(), trigger.getJobDetail().getGroup());
    nextRun = scheduler.scheduleJob(trigger.getJobDetail(), trigger);
}
]]> http://www.redstream.nl/2007/07/25/weird-quartz-scheduler-behaviour/feed/ 0 Scheduling with Spring and Quartz http://www.redstream.nl/2007/04/26/scheduling-with-spring-and-quartz/ http://www.redstream.nl/2007/04/26/scheduling-with-spring-and-quartz/#comments Thu, 26 Apr 2007 06:20:56 +0000 Pascal Alma http://www.pascalalma.net/?p=31 Continue reading →]]>

Just a small post about something I noticed in Quartz. I wanted to offer the user a screen with functionality so they could (re)schedule a batch job which then would do all kinds of batch stuf. To schedule the job in my application I used the following Java code:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32

public void resetScheduleJob() throws CustomSystemException {
 
      StdScheduler scheduler = (StdScheduler)MyQueueContext.getContext().getBean("scheduler");
 
      CronTriggerBean trigger = (CronTriggerBean)MyQueueContext.getContext().getBean("batchProducerTrigger");
 
      try {
           trigger.setCronExpression(getCronExpression());
 
           scheduler.scheduleJob(trigger.getJobDetail(), trigger);
 
      } catch (ParseException pe) {
         throw new CustomSystemException (pe);
      } catch (SchedulerException se) {
         throw new CustomSystemException (se);
      }
      LOG.info("Next run will be at: " + trigger.getNextFireTime());
   }
}
private String getCronExpression() {
 
      // Small trick to get the hours of the day correct.
      String hours = null;
      if (startTime > endTime) {
         hours = endTime + "-23,0-" + startTime;
      } else if (startTime < endTime) {
         hours = startTime + "-" + endTime;
      } else {
         hours = "0";
      }
      return "0 0/" + interval + " " + hours + " ? * " + days;
   }


So this code runs fine the first time when it is called. But when you call it the second time (after the job exists) you will get:

org.quartz.ObjectAlreadyExistsException: Unable to store Job with name: 'batchProducerJob' and group: 'DEFAULT', because one already exists with this identification.

So I rewrote my code to:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19

 public void resetScheduleJob() throws CustomSystemException {
      StdScheduler scheduler = (StdScheduler)MyQueueContext.getContext().getBean("scheduler");
 
      CronTriggerBean trigger = (CronTriggerBean)MyQueueContext.getContext().getBean("batchProducerTrigger");
 
      try {
         trigger.setCronExpression(getCronExpression());
 
         scheduler.rescheduleJob(job.getName(), job.getGroup(), trigger);
 
         scheduler.start();
 
      } catch (ParseException pe) {
         throw new CustomSystemException (pe);
      } catch (SchedulerException se) {
         throw new CustomSystemException (se);
      }
      LOG.info("Next run will be at: " + trigger.getNextFireTime());
   }

Now this code won’t fail if you call it several times….. Actually, it doesn’t do anything! I would expect an exception if the scheduler must have an existing job before it can reschedule one. But nothing there, I only found out that my job wasn’t started at all. So the trick is to check if there is a job with the same name, and if one is found, do the reschedule, otherwise the ‘normal’ schedule. Since I wasn’t expecting this behaviour I thought may be there are more persons running into this so here is the solution:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26

public void resetScheduleJob() throws CustomSystemException {
      StdScheduler scheduler = (StdScheduler)MyQueueContext.getContext().getBean("scheduler");
 
      CronTriggerBean trigger = (CronTriggerBean)MyQueueContext.getContext().getBean("batchProducerTrigger");
 
      try {
         trigger.setCronExpression(getCronExpression());
 
         JobDetail job = scheduler.getJobDetail(trigger.getJobDetail().getName(), trigger.getJobDetail().getGroup());
         LOG.debug("Job found = " + job);
 
         if (job == null) {
           scheduler.scheduleJob(trigger.getJobDetail(), trigger);
         } else {
            scheduler.rescheduleJob(job.getName(), job.getGroup(), trigger);
         }
 
         scheduler.start();
 
      } catch (ParseException pe) {
         throw new CustomSystemException (pe);
      } catch (SchedulerException se) {
         throw new CustomSystemException (se);
      }
      LOG.info("Next run will be at: " + trigger.getNextFireTime());
   }

And to make this example complete here is my Spring configuration:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans SYSTEM "../dtd/spring-beans.dtd">
<beans>
	<bean id="batchProducerJob" class="org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean">
	  <property name="targetObject" ref="batchProducer" />
	  <property name="targetMethod" value="start" />
	</bean>
	<bean id="batchProducerTrigger" class="org.springframework.scheduling.quartz.CronTriggerBean">
	    <property name="jobDetail" ref="batchProducerJob" />
        </bean>
	<bean id="scheduler" class="org.springframework.scheduling.quartz.SchedulerFactoryBean">
           <!-- intentionally left empty -->
	</bean>
        <bean id="batchProducerScheduler" class="net.pascalalma.batch.schedulers.BatchProducerScheduler">
	    <property name="startTime" value="${batch.produce.starthour}" />
	    <property name="endTime" value="${batch.produce.endhour}" />
	    <property name="interval" value="${batch.produce.interval}" />
	    <property name="days" value="${batch.produce.days}" />
       </bean>
</beans>
]]> http://www.redstream.nl/2007/04/26/scheduling-with-spring-and-quartz/feed/ 9