How to move job execution to a different instance based on custom criteria?

[devurandom]

I read #344 and am interested in a similar feature, or in a hint how to implement something like this with existing capabilities.

Context: Certain Quartz instances support certain jobs (they might implement the job class, but not a certain feature of it, or be currently not able to execute it).

What I am looking for: A way to prevent an instance from acquiring a job based on the result of a callback function ¹, or alternatively a way for instances to reject execution of jobs based on a callback ², so that another instance can try to acquire the job. These callbacks need to be executed on the instance where the job would be executed.

How would I do that within the features Quartz offers currently?

I believe this is different from org.quartz.TriggerListener#vetoJobExecution, since if that returns true the job will not be executed at all, while I want it to be executed by a different instance.

Footnotes

1. This callback would probably be called at around the time when org.quartz.core.QuartzSchedulerThread#run calls org.quartz.spi.JobStore#acquireNextTriggers? ↩

2. This callback would probably be called before org.quartz.core.QuartzSchedulerThread#run creates the org.quartz.core.JobRunShell? ↩