当一段时间没有运行另一个作业时，如何配置Quartz.net来运行一个作业

Question

Assume I have two Quartz.net jobs that

• downloads a CSV file with a delta of changes for a period (eg 24h) and then imports the data (called IncrementalImportJob )
• downloads a CSV file with a all the records and then imports the data (called FullImportJob )

The requirement is that IncrementalImportJob at a minimum once for the period (eg 24h). If that window is missed, or the job didn't complete successfully, then FullImportJob should run instead. The reason is that changes for that (missed) day would not be imported. This condition is rather exceptional.

The FullImportJob requires resources (time, CPU, database, memory) to import all the data, which may impact other systems. Further, the delta of changes are often minimal or non-existent. So the goal is to favour running the IncrementalImportJob when possible.

How does one configure quartz.net to run FullImportJob if IncrementalImportJob hasn't completed successfully in a specific time period (say 24h)?

Searching the web for "quartz.net recovery" and "quartz.net misfire" doesn't reveal whether its supported or whether its even possible.

Answer 1

There is native misfire handling in quartz.net, however it only goes as far as specifying whether the job should fire immediately again, or after a period of time or a number of times after misfiring.

I think one option is to handle this internally from IncrementalImportJob.

try
{
    //download data
    //import data
}
catch (Exception e) //something went wrong
{
   //log the error
   UpdateFullImportJobTrigger(sched);
}

//Reschedule FullImportJob to run at a time of your choosing. 
public void UpdateFullImportJobTrigger(IScheduler sched)
{
   Trigger oldTrigger = sched.getTrigger(triggerKey("oldTrigger", "group1");
   TriggerBuilder tb = oldTrigger.getTriggerBuilder();

   //if you want it to run based on a schedule use this:
   Trigger newTrigger = tb.withSchedule(simpleSchedule()
  .withIntervalInSeconds(10)
  .withRepeatCount(10)
  .build();

   sched.rescheduleJob(oldTrigger.getKey(), newTrigger);

   //or use simple trigger if you want it to run immediately and only once so that 
   //it runs again on schedule the next time.
}

This is one way of doing it. Another would be abstracting this logic to a maintenance job that checks the logs every so often and if it finds a failure message from IncrementalImportJob, it fires FullImportJob. However, this depends to some extent on your logging system (most people use NLog or log4net).

If on the other hand, your concern is that the job never ran in the first place because, for instance, the app/database/server was down, you could schedule FullImportJob to fire a few hours later and check if IncrementalImportJob has fired as follows:

//this is done from FullImportJob
//how you retrieve triggerKey will depend on whether
//you are using RAMJobStore or ADO.NET JobStore
public void Execute(IJobExecutionContext context)
{
    ITrigger incImportJobTrigger = context.Scheduler.GetTrigger(triggerKey);

    //if the job has been rescheduled with a new time quartz will set this to null
    if (!incImportJobTrigger.GetPreviousFireTimeUtc().HasValue) return;

    DateTimeOffset utcTime = incImportJobTrigger.GetPreviousFireTimeUtc().Value;
    DateTime previousTireTime = utcTime.LocalDateTime;

    if (previousTireTime.Day == DateTime.Now.Day) return; 

    //IncrementalImportJob has not ran today, let's run FullImportJob 
}

Hope this helps.