Quartz scheduled job not firing - possible unhandled exception?

Question

I have a web application with scheduled jobs using the Quartz library. Recently I encountered cases where a job didn't seem like it was being fired. I did some reading and apparently if the job throws an exception, the Quartz scheduler will attempt to execute the job again. Is this true?

In any case, I did some troubleshooting based on the assumption that the above statement is true. So let's say I have the following code snippet:

try {
   method.invoke(object, params);
}
catch (ExceptionA ea) {
   ea.printStackTrace();
}
catch (ExceptionB eb) {
   eb.printStackTrace();
}
// and so on so forth, catching a bunch of specific Exceptions

The important point here to note is that Exception itself is not being caught.

So let's say the method being invoked throws an exception which is not handled.

public void methodBeingInvoked() throws UnhandledException {

What happens here?

Kieren Dixon Kieren Dixon · Accepted Answer · 2011-11-14T01:19:42

Any Throwable thrown from a Job will be caught by Quartz and wrapped in a JobExecutionException, and not refired. See the source code for JobRunShell#run

There is some documentation on the Quartz website which contradicts this, but after looking at Quartz 1.8.x/2.0.x/2.1.x source code, the documentation is wrong for all versions.

A Job's execute method should contain a try-catch block that handles all possible exceptions.

If a job throws an exception, Quartz will typically immediately re-execute it (and it will likely throw the same exception again). It's better if the job catches all exception it may encounter, handle them, and reschedule itself, or other jobs. to work around the issue.

Quartz scheduled job not firing - possible unhandled exception?

1 Answers