Handling job class removals/changes

[leonluc-dev]

I currently have a job added like this:

JobKey jobKey = new JobKey("MyTestJobKey", "TestGroup");
services.AddJob<MyTestJob>(jobKey, j => j
    .WithDescription("A test job")
);

This job is properly persisted in the MongoDB database. However, an issue arises when I need to change the class name of MyTestJob.
Once I change the class name (for example from MyTestJob to MyTestJob2) or remove the class altogether and re-run the scheduler, the scheduler factory fails with the following error:

Quartz.JobPersistenceException: Job class cannot be null.
 ---> System.ArgumentException: Job class cannot be null.
   at Quartz.Impl.JobDetailImpl.set_JobType(Type value)
   at Quartz.Impl.JobDetailImpl..ctor(JobKey key, Type jobType, String description, Boolean isDurable, Boolean requestsRecovery, JobDataMap jobDataMap, Nullable`1 disallowConcurrentExecution, Nullable`1 persistJobDataAfterExecution)
   at Quartz.JobBuilder.Build()
   at Quartz.Spi.MongoDbJobStore.Models.JobDetail.GetJobDetail()
   at Quartz.Spi.MongoDbJobStore.MongoDbJobStore.ReplaceTriggerInternal(TriggerKey triggerKey, IOperableTrigger newTrigger)
   at Quartz.Spi.MongoDbJobStore.MongoDbJobStore.ReplaceTrigger(TriggerKey triggerKey, IOperableTrigger newTrigger, CancellationToken token)
   --- End of inner exception stack trace ---
   at Quartz.Spi.MongoDbJobStore.MongoDbJobStore.ReplaceTrigger(TriggerKey triggerKey, IOperableTrigger newTrigger, CancellationToken token)
   at Quartz.Core.QuartzScheduler.RescheduleJob(TriggerKey triggerKey, ITrigger newTrigger, CancellationToken cancellationToken)
   at Quartz.Xml.XMLSchedulingDataProcessor.ScheduleJobs(IScheduler sched, CancellationToken cancellationToken)
   at Quartz.ServiceCollectionSchedulerFactory.InitializeScheduler(IScheduler scheduler, CancellationToken cancellationToken)
   at Quartz.ServiceCollectionSchedulerFactory.GetScheduler(CancellationToken cancellationToken)

This is expected, as the class name it's trying to restore no longer exists. But is there a way to gracefully handle this and remove or ignore any jobs that no longer have a valid class associated with them from the MongoDB store?

[leonluc-dev]

The above error relates to #48 , so I've merged the two issues and closed this one.