Krish Narukulla created FLINK-37102: ---------------------------------------
Summary: ClassNotFoundException for ParquetColumnarRowInputFormat Key: FLINK-37102 URL: https://issues.apache.org/jira/browse/FLINK-37102 Project: Flink Issue Type: Bug Environment: h4. *Steps to Reproduce* # Package a Flink job using the {{flink-parquet}} format dependency into a fat JAR. # Deploy the JAR to a Kubernetes-based Flink cluster (Flink version 1.18.1). # Submit the job via the Flink client. # The job fails during execution with a {{ClassNotFoundException}} for {{{}org.apache.flink.formats.parquet.ParquetColumnarRowInputFormat{}}}. h4. *Root Cause Analysis* The issue is likely caused by one or more of the following: # *Parquet Dependency is present in fat jar.* # *Shading/Packaging Issue:* If a dependency is shaded incorrectly or excluded during JAR packaging, it can lead to runtime class-loading errors. # *ClassLoader Scope:* Flink’s classloader may not be able to resolve the class due to dependency isolation policies when executing the job. Reporter: Krish Narukulla While running a Flink job on Flink 1.18.1 deployed on Kubernetes, we encountered a {{ClassNotFoundException}} for {{{}org.apache.flink.formats.parquet.ParquetColumnarRowInputFormat{}}}. The job’s dependencies were bundled into a fat JAR, which was deployed in a custom folder ({{{}/opt/flink/<custom-folder>/fat.jar{}}}) on the task managers. Below are the key details of the issue: *Environment:* * Flink Version: 1.18.1 * Deployment: Kubernetes * Dependencies: Packaged into a fat JAR located at {{/opt/flink/<custom-folder>/fat.jar}} *Error Stack Trace (Truncated):* {code:java} Caused by: java.lang.ClassNotFoundException: org.apache.flink.formats.parquet.ParquetColumnarRowInputFormat at jdk.internal.loader.BuiltinClassLoader.loadClass(Unknown Source) at jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) ... at org.apache.flink.runtime.executiongraph.ExecutionJobVertex.initialize(ExecutionJobVertex.java:225) ... {code} -- This message was sent by Atlassian Jira (v8.20.10#820010)