Jason Gustafson created KAFKA-13155: ---------------------------------------
Summary: ConcurrentModificationException in TransactionalMessageCopier Key: KAFKA-13155 URL: https://issues.apache.org/jira/browse/KAFKA-13155 Project: Kafka Issue Type: Bug Reporter: Jason Gustafson Caught this exception in a system test run: ``` [2021-08-02 07:51:54,528] ERROR Uncaught exception in thread 'transactional-message-copier-shutdown-hook': (org.apache.kafka.common.utils.KafkaThread) java.util.ConcurrentModificationException: KafkaConsumer is not safe for multi-threaded access at org.apache.kafka.clients.consumer.KafkaConsumer.acquire(KafkaConsumer.java:2447) at org.apache.kafka.clients.consumer.KafkaConsumer.close(KafkaConsumer.java:2330) at org.apache.kafka.clients.consumer.KafkaConsumer.close(KafkaConsumer.java:2308) at org.apache.kafka.tools.TransactionalMessageCopier.lambda$main$1(TransactionalMessageCopier.java:331) at java.lang.Thread.run(Thread.java:748) ``` The pattern for closing the consumer is not safe. -- This message was sent by Atlassian Jira (v8.3.4#803005)