Fix exception handling in the data loader importing to handle the unkown exceptions properly

[thongdk8]

Description

This PR addresses the issue of unexpected exceptions (non-TransactionException) are not properly caught when importing data in transaction mode with misconfigured transaction managers, causing the import process to fail ungracefully.

For example, in the STORAGE mode of importing:

• Using single-crud-operation transaction manager throws UnsupportedOperationException when starting a transaction
• Start transaction while connecting to a cluster configured with single-crud-operation results in grpc.StatusRuntimeException: UNIMPLEMENTED on the client side (using scalardb-cluster-data-loader)

These exceptions bypass the existing TransactionException handler, leaving transactions unaborted and errors unlogged with proper context.

Related issues and/or PRs

N/A

Changes made

• Added a generic catch (Exception e) block in ImportProcessor.processTransactionBatch() to handle unexpected exceptions
• Enhanced error logging to include batch ID and data chunk ID for better debugging
• Ensured transactions are properly aborted even when unexpected exceptions occur
• Error messages now include exception class name and message in format: "Unexpected error: <ExceptionClass> - <message>"
• Added unit test process_withUnexpectedExceptionInTransaction_shouldHandleGracefully() to verify the new exception handling

Checklist

• I have commented my code, particularly in hard-to-understand areas.
• I have updated the documentation to reflect the changes.
• I have considered whether similar issues could occur in other products, components, or modules if this PR is for bug fixes.
• Any remaining open issues linked to this PR are documented and up-to-date (Jira, GitHub, etc.).
• Tests (unit, integration, etc.) have been added for the changes.
• My changes generate no new warnings.
• Any dependent changes in other PRs have been merged and published.

Additional notes (optional)

NA

Release notes

Fixed data-loader to properly handle unexpected exceptions during transaction processing for importing, ensuring transactions are aborted and errors are logged with proper context.

[thongdk8]

/gemini review

[gemini-code-assist]

Code Review

This pull request effectively addresses a critical issue in the data loader's exception handling by catching unexpected exceptions during transaction processing, ensuring transactions are properly aborted, and improving error logging. The changes are logical and the inclusion of a unit test to verify the new behavior is commendable. I have a few suggestions to further enhance the code's robustness and maintainability.

[Copilot]

Pull Request Overview

This PR enhances exception handling in the data loader's transaction processing to properly catch and handle unexpected exceptions (non-TransactionException) that can occur with misconfigured transaction managers. The changes ensure transactions are properly aborted and errors are logged with appropriate context even when unexpected exceptions occur.

Key Changes:

• Added a generic catch (Exception e) block to handle unexpected exceptions during transaction processing
• Enhanced error logging to include batch ID and data chunk ID for better debugging context
• Added unit test to verify graceful handling of unexpected exceptions

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
data-loader/core/src/main/java/com/scalar/db/dataloader/core/dataimport/processor/ImportProcessor.java	Added generic exception handler with enhanced logging and proper transaction abort logic for unexpected exceptions
data-loader/core/src/test/java/com/scalar/db/dataloader/core/dataimport/processor/ImportProcessorTest.java	Added unit test process_withUnexpectedExceptionInTransaction_shouldHandleGracefully() to verify proper handling of unexpected exceptions in transaction mode

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[brfrn169]

LGTM! Thank you!

[ypeckstadt]

LGTM. Thank you.

[inv-jishnu]

LGTM!
Thank you!

[Torch3333]

LGTM, thank you!

[komamitsu]

LGTM, thank you!

[feeblefakie]

LGTM! Thank you!