Access JobParameters via JobInstance

[Walnussbaer]

Currently, I am trying to implement some logic that tries to find out which JobInstances should be restarted and which not.

This is how I do it at the moment:

private @NonNull Set<JobInstance> getIncompleteLegacyParameterValueJobInstances() {
    try {
        final var jobInstanceCount = jobExplorer.getJobInstanceCount(LegacyParameterValueJobConfig.JOB_NAME);
        final var pageSize = 5;
        final var pageCount = (long) Math.ceil((double) jobInstanceCount / pageSize);
        var explorerIndex = 0;
        final var jobInstances = new HashSet<JobInstance>();
        for (int pageIndex = 1; pageIndex <= pageCount; pageIndex++) {
            jobInstances.addAll(jobExplorer.getJobInstances(LegacyParameterValueJobConfig.JOB_NAME, explorerIndex, pageSize));
            explorerIndex += pageSize;
        }

        return jobInstances
            .stream()
            .filter(instance -> {
                final var latestExecution = jobExplorer.getLastJobExecution(instance);
                // TODO: get JobParameters and make this method return a custom value object with JobInstance and JobParameters

                // TODO: what about job executions with state UNKNOWN? Wait for spring batch 6 or do manual recovery?

                return (
                    latestExecution == null ||
                    (latestExecution.getExitStatus().equals(ExitStatus.FAILED) || latestExecution.getExitStatus().equals(ExitStatus.STOPPED))
                );
            })
            .collect(Collectors.toSet());
    } catch (NoSuchJobException noSuchJobException) {
        throw new IllegalStateException("No known job with name  " + LegacyParameterValueJobConfig.JOB_NAME, noSuchJobException);
    }
}

The first TODO already summarizes my problem/questions: Why can't I access the JobParamaters of some JobInstance?

As far as I know, a JobInstance is defined via a combination of Job + JobParamters .

Currently, to get the JobParameters of some JobInstance, I have to get at least one JobExecution of that JobInstance.
But all the JobExecutions should have exactly the same JobParameters right? At least if they are identifying.
And is there a better way to access JobParameters of some JobInstance that I don't see yet?
Thanks for any help! :)

[fmbenhassine]

But all the JobExecutions should have exactly the same JobParameters right? At least if they are identifying.

That's correct. All job executions of a given job instance have the same identifying job parameters, but can have different non-identifying parameters. That's why there is no job parameters attached to a given instance, you need to get at least one of the executions and extract identifying job parameters for it.

// TODO: what about job executions with state UNKNOWN? Wait for spring batch 6 or do manual recovery?

It is not possible to restart a job execution in an "UNKNOWN" status, even with Spring Batch 6 (see

spring-batch/spring-batch-core/src/main/java/org/springframework/batch/core/launch/support/SimpleJobOperator.java

Lines 427 to 435 in 7dec638

	if (jobStatus == BatchStatus.COMPLETED || jobStatus == BatchStatus.ABANDONED
	|| jobStatus == BatchStatus.UNKNOWN) {
	if (logger.isWarnEnabled()) {
	logger.warn(
	"JobExecution is already complete or abandoned or in an unknown state, and therefore cannot be recovered: "
	+ jobExecution);
	}
	return jobExecution;
	}

). These executions are not restartable and should be excluded from your utility method

---

Does that answer your questions?

[Walnussbaer]

That's correct. All job executions of a given job instance have the same identifying job parameters, but can have different non-identifying parameters. That's why there is no job parameters attached to a given instance, you need to get at least one of the executions and extract identifying job parameters for it.

Okay, thank you, that makes sense to me!

About the jobs with UNKNOWN status:
In my TODO, I am refering to this planned feature in Spring Batch 6: https://docs.spring.io/spring-batch/reference/6.0/whatsnew.html#ability-to-recover-failed-job-executions

But I just thought about this and I think I get your point, my utility method should not tangle with job recovery, so it should not return jobs with UNKNOWN state. The recovery part should take place somewhere else in my app.

Thank you so much for your quick response, really appreciate it!