[KAFKA-8523] InsertField transformation fails when encountering tombstone event

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.0.3, 1.1.2, 2.0.2, 2.1.2, 2.2.2, 2.4.0, 2.3.1
• Component/s: connect
• Assignee: Unassigned
• Reporter: Gunnar Morling
• Reviewer: Randall Hauch
• Created: 11/Jun/19 08:53
• Updated: 25/Mar/20 19:27
• Resolved: 03/Oct/19 19:24

Description

When applying the InsertField transformation to a tombstone event, an exception is raised:

org.apache.kafka.connect.errors.DataException: Only Map objects supported in absence of schema for [field insertion], found: null
	at org.apache.kafka.connect.transforms.util.Requirements.requireMap(Requirements.java:38)
	at org.apache.kafka.connect.transforms.InsertField.applySchemaless(InsertField.java:138)
	at org.apache.kafka.connect.transforms.InsertField.apply(InsertField.java:131)
	at org.apache.kafka.connect.transforms.InsertFieldTest.tombstone(InsertFieldTest.java:128)

AFAICS, the transform can still be made working in in this case by simply building up a new value map from scratch.

Update as per the discussion in the comments: tombstones should be left as-is by this SMT, as any insertion would defeat their purpose of enabling log compaction.

Issue Links

• is fixed by: KAFKA-9707 InsertField.Key transformation should apply to tombstone records
• relates to: KAFKA-7052 ExtractField SMT throws NPE - needs clearer error message
• links to: GitHub Pull Request #6914