[Java][Debezium] Fix NPE in debeziumRecordInstant for DELETE events

[liferoad]

What changed

• Updated KafkaConnectUtils.debeziumRecordInstant(SourceRecord) to avoid dereferencing valueSchema() when it is null.
• Preserved existing ts_ms extraction path for normal struct-valued Debezium records.
• Added fallback to sourceOffset.ts_usec (microseconds) for DELETE events and converted to epoch millis.
• Added/updated unit tests in KafkaConnectSchemaTest for:
  • null valueSchema + ts_usec fallback success
  • missing timestamp sources throws IllegalArgumentException

Why

Fixes a NullPointerException reported for Debezium DELETE operations where value and valueSchema are null but timestamp exists in source offset metadata.

Fixes #37738

[gemini-code-assist]

Summary of Changes

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This pull request addresses a NullPointerException that occurred during Debezium DELETE operations when value and valueSchema were null, but timestamp information was available in the source offset metadata. The changes enhance the timestamp extraction logic to gracefully handle these edge cases, ensuring that Debezium records, particularly DELETE events, are processed correctly without errors, thereby improving the stability and reliability of the Debezium connector.

Highlights

• Timestamp Extraction Logic: The debeziumRecordInstant method was updated to safely handle cases where valueSchema is null, specifically for Debezium DELETE events.
• Fallback for DELETE Events: A new fallback mechanism was introduced to extract timestamps from sourceOffset.ts_usec (microseconds) when the primary ts_ms field in the record value is unavailable.
• Preserved Existing Behavior: The original logic for extracting ts_ms from struct-valued Debezium records remains intact for non-DELETE events.
• Enhanced Unit Tests: New unit tests were added to cover scenarios involving null valueSchema with ts_usec fallback and cases where no valid timestamp source is present, ensuring robust error handling.

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Changelog

• sdks/java/io/debezium/src/main/java/org/apache/beam/io/debezium/KafkaConnectUtils.java
  • Modified the debeziumRecordInstant method to first check for a non-null valueSchema and ts_ms field in the record value.
  • Added a secondary check to extract the timestamp from record.sourceOffset().get("ts_usec") if the primary method fails, converting microseconds to milliseconds.
  • Updated the IllegalArgumentException message to reflect both possible timestamp sources.
• sdks/java/io/debezium/src/test/java/org/apache/beam/io/debezium/KafkaConnectSchemaTest.java
  • Updated the assertion message in testTimestampRequired to match the new exception message.
  • Added testDebeziumRecordInstantNullValueSchema to verify correct timestamp extraction from ts_usec when valueSchema is null.
  • Added testDebeziumRecordInstantMissingTimestamp to confirm that an IllegalArgumentException is thrown when neither ts_ms nor ts_usec is available.

Activity

• No human activity has been recorded for this pull request yet.

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[github-actions]

Assigning reviewers:

R: @Abacn for label java.

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[Abacn]

nit: import the name. Not sure why it used fully qualified name at the first place.

[Abacn]

Thanks!

Tested locally, delete event now propagated successfully.

[Abacn]

As a follow up:

beam/sdks/java/io/debezium/src/main/java/org/apache/beam/io/debezium/SourceRecordJson.java

Line 80 in ea473d2

this.event = new Event(null, null, null);

We may consider including potentially useful information (e.g. key, kafka partition) in this case. After this fix, the tombstone event is recorded as an empty element here.

For now the current form is sufficient to resolve the NPE bug.