Inaccurate error message when using ResourcelessJobRepository with a partitioned step

[monnetchr]

Bug description
The ResourcelessJobRepository cannot be used with a Partitioner:

[main] ERROR org.springframework.batch.core.step.AbstractStep - Encountered an error executing step step in job partitionJob
org.springframework.batch.core.JobExecutionException: Cannot restart step from STARTING status.  The old execution may still be executing, so you may need to verify manually that this is the case.

Steps to reproduce
Simply change spring-batch-samples/src/main/resources/simple-job-launcher-context.xml to use ResourcelessJobRepository and then run spring-batch-samples/src/test/java/org/springframework/batch/samples/partition/file/PartitionFileJobFunctionalTests.java

[fmbenhassine]

The resourceless job repository does not support features involving the execution context (including partitioned steps). This is mentioned in the javadocs of the class: https://docs.spring.io/spring-batch/docs/current/api/org/springframework/batch/core/repository/support/ResourcelessJobRepository.html and in the reference docs here: https://docs.spring.io/spring-batch/reference/whatsnew.html#new-resourceless-job-repository

You need to configure another job repository implementation that supports batch-metadata. I am closing this issue now as I believe it answers your concern, but please add a comment if you need more support on this. Thank you.

[fmbenhassine]

I must admit the error message is confusing, there is no restart in that sample yet the message is mentioning restart. I will re-open this issue and change it into an enhancement.

[kwondh5217]

Hi @fmbenhassine, I would like to contribute to this issue.

To improve clarity, would it make sense to explicitly prevent the use of ResourcelessJobRepository with partitioned steps by throwing an exception?

Proposed change:

@Override
public Set<StepExecution> split(StepExecution stepExecution, int gridSize) throws JobExecutionException {
    if (jobRepository instanceof ResourcelessJobRepository) {
        throw new JobExecutionException("ResourcelessJobRepository cannot be used with partitioned steps "
                                        + "as it does not support execution context.");
    }
    ...

[fmbenhassine]

This was fixed as part of 90d8959.

Steps to reproduce
Simply change spring-batch-samples/src/main/resources/simple-job-launcher-context.xml to use ResourcelessJobRepository and then run spring-batch-samples/src/test/java/org/springframework/batch/samples/partition/file/PartitionFileJobFunctionalTests.java

I tried that sample with 6.0.0-RC2 and now it prints:

12:27:34.354 [main] INFO  o.s.b.c.c.x.CoreNamespaceHandler - DEPRECATION NOTE: The batch XML namespace is deprecated as of Spring Batch 6.0 and will be removed in version 7.0.
12:27:34.566 [main] INFO  o.s.b.c.s.i.ChunkOrientedTasklet - DEPRECATION NOTE: The legacy implementation of the chunk-oriented processing model is deprecated as of Spring Batch 6.0 and will be removed in version 7.0.
12:27:35.250 [main] INFO  o.s.b.c.l.s.TaskExecutorJobLauncher - Job: [FlowJob: [name=partitionJob]] launched with the following parameters: [{JobParameter{name='random', value=1393027390114809605, type=class java.lang.Long, identifying=true}}]
12:27:35.254 [main] INFO  o.s.b.c.j.SimpleStepHandler - Executing step: [step]
12:27:35.286 [SimpleAsyncTaskExecutor-2] INFO  o.s.b.c.s.AbstractStep - Step: [step1:partition1] executed in 28ms
12:27:35.286 [SimpleAsyncTaskExecutor-1] INFO  o.s.b.c.s.AbstractStep - Step: [step1:partition0] executed in 28ms
12:27:35.287 [main] INFO  o.s.b.c.s.AbstractStep - Step: [step] executed in 32ms
12:27:35.288 [main] INFO  o.s.b.c.l.s.TaskExecutorJobLauncher - Job: [FlowJob: [name=partitionJob]] completed with the following parameters: [{JobParameter{name='random', value=1393027390114809605, type=class java.lang.Long, identifying=true}}] and the following status: [COMPLETED] in 34ms

which does not log the confusing error message anymore.