There are two types of the scheduled jobs which OpenHub supports:

1. jobs which can run on random node and can be executed parallel (it's not condition to start jobs in the same time)
2. jobs which can run only once in the cluster, no matter on which node (note: we don't take into consideration the possibility that scheduled job has to run on specific node only) 

If there is only one OpenHub instance then doesn't matter which type of scheduled job is used.

API

• Quartz configuration API is in org.openhubframework.openhub.core.config.QuartzConfig package
• jobs and triggers are defined with the following annotations (package org.openhubframework.openhub.api.common.quartz)
  • QuartzJob - defines one quartz Job with simple trigger QuartzSimpleTrigger or cron trigger QuartzCronTrigger
    • defines execute type in the cluster (JobExecuteTypeInCluster):
      • CONCURRENT - job can be executed parralel on nodes
      • NOT_CONCURRENT - job can run only on one node
  • QuartzSimpleTrigger - this type of trigger is used to fire a job repeated at a specified interval
  • QuartzCronTrigger - this type of trigger is used to fire a job at given time, defined by Unix 'cron-like' schedule definitions.

Solution

• we use directly Quartz job scheduler, not Camel-quartz component 
• implementation classes are in org.openhubframework.openhub.core.common.quartz package
• basic implementation is in the class org.openhubframework.openhub.core.common.quartz.scheduler.DefaultScheduler that creates all defined scheduled jobs
  • information about concurrent jobs (=CONCURRENT) are stored in memory
  • information about not concurrent jobs (=NOT_CONCURRENT) are stored in database - quartz uses default database schema for storing scheduled jobs (for H2 DB defined in db/db/migration/h2/V1_0_2__schema_quartz.sql in our project)
    • see how quartz stores jobs
• scheduler is started by org.openhubframework.openhub.core.common.quartz.scheduler.QuartzSchedulerLifecycle

Configuration examples

@OpenHubQuartzJob(name = "AsyncPostponedJob", executeTypeInCluster = JobExecuteTypeInCluster.NOT_CONCURRENT,
        simpleTriggers = @QuartzSimpleTrigger(repeatIntervalMillis = 30000))
public void invokePostponedJob() {}

@OpenHubQuartzJob(name = "MoreTriggerJob", executeTypeInCluster = JobExecuteTypeInCluster.CONCURRENT,
        cronTriggers = {
                @QuartzCronTrigger(cronExpression = "0 00 23 ? * *",
                        name = "FirstTriggerForJob",
                        group = "MoreTriggerGroup"),
                @QuartzCronTrigger(cronExpression = "0 00 10 ? * *",
                        misfireInstruction = CronTriggerMisfireInstruction.FIRE_ONCE_NOW,
                        name = "SecondTriggerForJob",
                        group = "MoreTriggerGroup")},
        simpleTriggers = {
                @QuartzSimpleTrigger(repeatIntervalMillis = 10000,
                        repeatCount = 20,
                        name = "ThirdTriggerForJob",
                        group = "MoreTriggerGroup"),
                @QuartzSimpleTrigger(repeatIntervalProperty = ASYNCH_PARTLY_FAILED_REPEAT_TIME_SEC,
                        intervalPropertyUnit = SimpleTriggerPropertyUnit.SECONDS,
                        misfireInstruction = SimpleTriggerMisfireInstruction.FIRE_NOW,
                        name = "FourthTriggerForJob",
                        group = "MoreTriggerGroup")
        })
public void invokeJob() {}