[FLINK-30434] The non-null check for transactionalIdPrefix is unnecessary in the KafkaWriter constructor

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Not A Problem
• Affects Version/s: 1.16.0, 1.14.6, 1.15.3
• Component/s: Connectors / Kafka
• Assignee: Unassigned
• Reporter: Zhengqi Zhang
• Created: 16/Dec/22 10:26
• Updated: 16/Dec/22 13:26
• Resolved: 16/Dec/22 13:26

Description

The non-null check for transactionalIdPrefix is unnecessary in the KafkaWriter constructor, especially when EXACTLY_ONCE semantics are not used.

First, when EXACTLY_ONCE semantics are used, a non-null check has been performed for transactionalIdPrefix in KafkaSinkBuilder.

Secondly, although the default value "kafka-sink" has been assigned to transactionalIdPrefix in KafkaSinkBuilder, if the user uses the setTransactionalIdPrefix method to set it to null, the construction method of KafkaWriter will throw an exception, even if the user does not use EXACTLY_ONCE semantics at this time.

Obviously, we should allow transactionalIdPrefix to be null when EXACTLY_ONCE semantics are not used.