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If your Spring Batch job is not committing database updates, there could be several reasons. Here's a checklist of common issues to investigate:

✅ 1. Transaction Management

Spring Batch relies on transaction management to control commit and rollback behavior. If your transactions are not configured correctly, updates won’t be persisted.

• Each Step runs within its own transaction scope.
• If the transaction fails or is rolled back, no database changes will be committed.

✅ 2. Transaction Propagation and Isolation Levels

• If the batch job is part of a larger transaction context, ensure it’s not waiting on a parent transaction that never commits.
• Verify your propagation and isolation levels—they can affect transaction visibility and commit timing.

✅ 3. Chunk Size Matters

• Spring Batch commits transactions after processing each chunk.
• If your chunk size is too large or an exception occurs within the chunk, the entire chunk will be rolled back.
• Example:

java

.chunk(10) // commits every 10 items

✅ 4. Step Execution Status

If the step fails or is marked with an unsuccessful status, the transaction will be rolled back automatically.

• Monitor logs or implement listeners to track failures.
• Example:

java

public ExitStatus afterStep(StepExecution stepExecution) {
    return stepExecution.getExitStatus();
}

✅ 5. Hibernate Flush Mode

If using Hibernate:

• Check the flush mode. Default is AUTO, which flushes changes at commit.
• If it's set to FlushMode.MANUAL, you'll need to flush manually:

java

entityManager.flush();

✅ 6. Error Handling

• Unhandled exceptions during a job/step cause automatic rollback.
• Ensure you're not swallowing exceptions silently.
• Add proper logging to capture any underlying issue:

java

try {
    // business logic
} catch (Exception e) {
    log.error("Step failed: ", e);
    throw e; // important to rethrow!
}

✅ 7. Auto-Commit Settings

• If auto-commit is disabled in your datasource but Spring isn’t managing transactions correctly, updates won’t be committed.
• Typically Spring Batch manages commits explicitly, but it’s good to check.

✅ 8. Misconfigured Job or Step

• Ensure TransactionManager is properly wired:

java

.transactionManager(new DataSourceTransactionManager(dataSource))

• Check for misconfigured or missing attributes in your job/step definitions.

✅ 9. Database Connection Stability

• A flaky or misconfigured datasource can cause unexpected failures.
• Monitor database logs for dropped connections or timeouts.

🔍 Debugging Tips

• Logs: Always examine logs for signs of rollback or transaction errors.
• Listeners: Implement StepExecutionListener or ItemProcessListener to debug lifecycle behavior.
• TransactionManager: If in doubt, explicitly declare the correct PlatformTransactionManager.