[KAFKA-13761] KafkaLog4jAppender deadlocks when idempotence is enabled

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 3.1.0, 3.0.0, 3.0.1
• Component/s: log
• Assignee: Unassigned
• Reporter: Yang Yu
• Created: 23/Mar/22 04:45
• Updated: 24/Mar/22 13:37

Description

KafkaLog4jAppender instantiates a KafkaProducer to append log entries to a Kafka topic. The producer.send operation may need to acquire locks during its execution. This can result in deadlocks when a log entry from the producer network thread is also at a log level that results in the entry being appended to a Kafka topic (KAFKA-6415).

https://github.com/apache/kafka/pull/11691 enables idempotence by default, and it introduced another place where the producer network thread can hit a deadlock. When calling TransactionManger#maybeAddPartition, the producer network thread will wait on the TransactionManager lock, and a deadlock can happen if TransactionManager also logs at INFO level. This is causing system test failures in log4j_appender_test.py

Similar to KAFKA-6415, a workaround will be setting log level to WARN for TransactionManager in VerifiableLog4jAppender.

 

Issue Links

• links to: GitHub Pull Request #11939