Quartz: Can schedule be shutdown automatically after job execution? - quartz-scheduler

As default, quartz schedule is not shutdown after job execution. Can schedule be shutdown automatically after job execution?

Yes, Scheduler has only start method. However, you can control the repeat count, i.e how many times the scheduler should trigger.
Check the below snippet.
trigger = newTrigger()
.withIdentity("trigger3", "group1")
.startAt(myTimeToStartFiring) // if a start time is not given (if this line were omitted), "now" is implied
.withSchedule(simpleSchedule()
.withIntervalInSeconds(10)
.withRepeatCount(10)) // note that 10 repeats will give a total of 11 firings
.forJob(myJob) // identify job with handle to its JobDetail itself
.build();

Related

What is a good use case for a delay task in Uber Cadence?

I want to implement a delay task and found a cadence cron example, how to use cadence to implement a delay task?
Cron is for periodic execution of some functionality.
If you need to delay a task you can call sleep and the beginning of the workflow and then call an activity that executes the task.
Cadence supports both activity and workflow delaying.
Activity delay can be achieved with Workflow.Sleep API
Workflow delay can be achieved with DelayStart option. See https://github.com/uber-go/cadence-client/blob/e66e2d4da8def80e7a5730b824a2de7a28f5c050/internal/client.go#L415
For regular workflows, this will delay execution that many seconds, then start.
For cron workflows, this will delay ONLY the FIRST execution. For example you want to set up an hourly cron workflow but you want it to start running from next week on Monday at 9AM. You can pass delayStart seconds option to delay till that Monday between 8AM and 9AM so it will start at 9AM since it's the next schedule.

Run scheduler to execute jobs at an interval from the completion of the previous job

I need to create schedulers to execute jobs(class files) at specified intervals..For Now, I'm using Quartz Scheduler which triggers the jobs at defined intervals from the time of triggering of it.
For Eg: Consider I'm giving a cron expression to run for every one hour starting at morning 9.My first run will be at 9 and my second run will be at 10 and so on.
If my job is taking 20 minutes to execute then in that case this method is not that much efficient.
What I need to do is to schedule a job for every one hour from the completion time of the previously ran job
For Eg: Consider my job to run every one hour is triggered at 9 and for the first run it took 20 minutes to run, so for the next time the job should trigger only at 10:20 instead of 10 (ie., one hour from the completion of previous ran job)
I need to know whether there are any methods in Quartz Scheduling to achieve this or any other logic I need to do.
If anyone could help me out on this,it would be very helpful for me.
You can easily achieve this by job-chaining your job executions. There are various approaches you can choose from:
(1) Implement a Quartz JobListener and in its jobWasExecuted method, that is invoked by Quartz whenever a job finishes executing, re-fire your job.
(2) Look at the Quartz JobChainingJobListener that you can use to implement simple job chaining scenarios. Please note that the functionality of this listener is very limited as it does not allow you to insert delays between job executions, there is no support for conditions that must be met before target jobs are executed etc. But you can use it as a good starting point to implement (1).
(3) Use QuartzDesk (our commercial product) or any other product that allows you to create job chains while externalizing and managing all job dependencies outside of your application. A job chain can have multiple target jobs that can be executed immediately, with a fixed delay or at arbitrary time in the future produced by a JavaScript expression. It also allows you to implement somewhat more sophisticated works flows, such as firing a target job when multiple source jobs complete their execution etc. I am attaching screenshots showing you what a simple job chain that re-executes Job1 with a 1 minute delay upon Job1's completion (with any job execution status) looks like:

How to set Akka actors run only for specific time period?

I have a big task,which i break down into smaller task and analyse them. I have a basic model.
Master,worker and listener .
Master creates the tasks,give them to worker actors. Once an worker actor completes,it asks for another task from the master. Once all task is completed ,they inform the listener. They usually take around less than 2 minutes to complete 1000 tasks.
Now,Some time the time taken for some tasks might be more than others. I want to set timer for each task,and if a task takes more time,then worker task should be aborted by the master and the task has to be resubmitted later as new one. How to implement this? I can calculate the time taken by a worker task,but how Master actor keeps tab on time taken by all worker actors in real time?
One way of handling this would be for each worker, on receipt of a task to start on, sets a timeout before changing state to process the task, eg:
context.setReceiveTimeout(5 minutes) // for the '5 minutes' notation - import scala.concurrent.duration._
If the timeout is received, the worker can abort the task (or whatever other action you deem appropriate - eg. kill itself, or pass a notification message back to the master). Don't forget to cancel the timeout (set duration = Duration.Undefined) if the task is completed or the like.

Quartz Service - Simple Triggers

I have a Quartz Job that I want to fire every minute. The job itself contains logic to check to see if there is a process to run and if there is, this job could take 45 minutes to complete.
Using a Simple Trigger, will Quartz fire this job off every minute even if there is one already running? Or if the interval is set to 1 minute, does that mean that Quartz will wait 1 minute after the job is done before it fires the next job?
If the trigger is set to fire every minute, it will fire every minute (and a new job instance will be created and invoked).
Unless the related job is marked #DisallowConcurrentExecution.

How to call a CronTriggerBean stored in a JDBCJobStore?

I need some help. I am using Quartz Scheduling and have configured a CronTrigger to run each night at 10PM. I am using the JDBCJobStore to take advantage of the Clustering.
The job runs at 10PM every night but I want to be able to call the job programmatically to run it on the fly if needed but I still want to take advantage of the clustering(Ie. I don't want multiple people being able to run the job).
Is there a way to get the CronJob from the store and run it while still taking advantage of the clustering option? For example now, the 1st server that wakes up the job runs, when the other server in the cluster wakes up it doesn't run if the job is already started.
I am able to do this like this but it start as a separate job.... which is not what I want.
scheduler = StdSchedulerFactory.getDefaultScheduler();
scheduler.start();
/ Create the JobDetail
JobDetail jobDetail = new JobDetail("cronTrigger", Scheduler.DEFAULT_GROUP, MyCronJob.class);
// Create a trigger that fires once right away
Trigger trigger = TriggerUtils.makeImmediateTrigger(0, 0);
trigger.setName("FireOnceNowTrigger");
scheduler.scheduleJob(jobDetail, trigger);
Assuming you know the name of the job you have already stored ("storedJob"), does this work for you?
Trigger trigger = TriggerUtils.makeImmediateTrigger(0, 0);
trigger.setName("FireOnceNowTrigger");
trigger.setJobName("storedJob");
trigger.setJobGroup(Scheduler.DEFAULT_GROUP);
scheduler.scheduleJob(trigger);