Hugo Gu created FLINK-34996: ------------------------------- Summary: Deserializer can't be instantiated when connector-kafka installed into Flink Libs Key: FLINK-34996 URL: https://issues.apache.org/jira/browse/FLINK-34996 Project: Flink Issue Type: Bug Components: Connectors / Kafka Reporter: Hugo Gu Attachments: image-2024-04-03-17-34-00-120.png, image-2024-04-03-17-37-55-105.png
The current implementation of the KafkaValueOnlyDeserializerWrapper Class instantiates Deserializer from the ClassLoader of the KafkaValueOnlyDeserializerWrapper itself as following figure shows. !image-2024-04-03-17-34-00-120.png|width=799,height=293! In case of both following conditions are met: 1. The connector-kafka get installed into Libs of Flink (rather than in the User Jar) 2. The user jar defines a customized Deserializer for Kafka Record. The instantiation of the custom deserializer will fail due to NoClassFound exception because it is indeed not available in the system class loader. As following figure illustrates !image-2024-04-03-17-37-55-105.png|width=413,height=452! It can be fixed by using either UserCodeClassLoader or the ClassLoader of current Thread. -- This message was sent by Atlassian Jira (v8.20.10#820010)