Scheduler needs to run only once but actually runs more then once on AEM 6.5?

[anasustic]

I have configured a scheduler in AEM6.5 and the idea is that it runs ONCE a night at 2AM

@Designate(ocd = TagVerificationScheduledTask.Config.class)
@Component(service = {Runnable.class})
public class TagVerificationScheduledTask implements Runnable {

    @ObjectClassDefinition(name = "scheduled task that verifies tags in blog articles",
            description = "A scheduled task that verifies tags in blog articles")
    public @interface Config {

        @AttributeDefinition(name = "Cron-job expression. Default: run every night at 2:00 AM.")
        String scheduler_expression() default "0 0 2 * * ?";

 The job runs on all three instances (one author and two publishers) and I want it to run on only one instance i.E. author.
How can I configure that?

O tried @Property(name="scheduler.runOn", value="SINGLE"); but it does not work. I also tried  @AttributeDefinition(name = "Run On") String scheduler_runOn() default "SINGLE"; but that also did not work.

[Mahedi_Sabuj]

Hi @anasustic,

I guess that you have multiple author and publish instances where the scheduler is running, possibly three instances in your case. This is why the email is sent three times at 2 AM.

[anasustic]

Hi @Mahedi_Sabuj 

Thanks a lot for your reply.

I have one Author and two Publish instances. 

Is there a way to configure the job to run only once and only on one instance?

[Mahedi_Sabuj]

It mostly depends on your use case. You can add the OSGi configuration for the scheduler only for the author run mode, ensuring it executes just once.

[divanshug]

Hi @Mahedi_Sabuj 

Please check the discussion here

https://experienceleaguecommunities.adobe.com/t5/adobe-experience-manager/aem-cloud-is-scheduler-run...

Regards,

Divanshu

[anasustic]

Hi @divanshug 

Thanks a lot for your reply. I am not sure how to configure it to run only on one node (i.E. author instance) using the documentation you provided:

@Property(name="scheduler.runOn", value="LEADER");

or

@Property(name="scheduler.runOn", value="SINGLE");

[Jörg_Hoh · Accepted solution]

The scheduler runs independently on each AEM instance; they don't know of each other (except for the replication, but that's a different story). That means every instance thinks of itself as a SINGLE instance, which at the same time is also a Cluster LEADER.

That means in your setup you implement this at best on the author only (make this service only running on author using OSGI configuration, see https://cqdump.joerghoh.de/2019/10/14/how-to-use-runmodes-correctly/)

[anasustic]

Thank you very much @Jörg_Hoh