Hi dear engineers,
Resently I encountered another issue, after I submited a flink sql job, it throws an exception: Caused by: java.lang.ClassCastException: cannot assign instance of org.apache.commons.collections.map.LinkedMap to field org.apache.flink.streaming.connectors.kafka.FlinkKafkaConsumerBase.pendingOffsetsToCommit of type org.apache.commons.collections.map.LinkedMap in instance of org.apache.flink.streaming.connectors.kafka.FlinkKafkaConsumer at java.io.ObjectStreamClass$FieldReflector.setObjFieldValues(ObjectStreamClass.java:2233) ~[?:1.8.0_162] at java.io.ObjectStreamClass.setObjFieldValues(ObjectStreamClass.java:1405) ~[?:1.8.0_162] at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2284) ~[?:1.8.0_162] at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2202) ~[?:1.8.0_162] at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2060) ~[?:1.8.0_162] at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1567) ~[?:1.8.0_162] at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2278) ~[?:1.8.0_162] at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2202) ~[?:1.8.0_162] at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2060) ~[?:1.8.0_162] at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1567) ~[?:1.8.0_162] at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2278) ~[?:1.8.0_162] at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2202) ~[?:1.8.0_162] at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2060) ~[?:1.8.0_162] at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1567) ~[?:1.8.0_162] at java.io.ObjectInputStream.readObject(ObjectInputStream.java:427) ~[?:1.8.0_162] at org.apache.flink.util.InstantiationUtil.deserializeObject(InstantiationUtil.java:615) ~[flink-dist_2.11-1.13.2.jar:1.13.2] at org.apache.flink.util.InstantiationUtil.deserializeObject(InstantiationUtil.java:600) ~[flink-dist_2.11-1.13.2.jar:1.13.2] at org.apache.flink.util.InstantiationUtil.deserializeObject(InstantiationUtil.java:587) ~[flink-dist_2.11-1.13.2.jar:1.13.2] at org.apache.flink.util.InstantiationUtil.readObjectFromConfig(InstantiationUtil.java:541) ~[flink-dist_2.11-1.13.2.jar:1.13.2] at org.apache.flink.streaming.api.graph.StreamConfig.getStreamOperatorFactory(StreamConfig.java:322) ~[flink-dist_2.11-1.13.2.jar:1.13.2] at org.apache.flink.streaming.runtime.tasks.OperatorChain.<init>(OperatorChain.java:159) ~[flink-dist_2.11-1.13.2.jar:1.13.2] at org.apache.flink.streaming.runtime.tasks.StreamTask.executeRestore(StreamTask.java:548) ~[flink-dist_2.11-1.13.2.jar:1.13.2] at org.apache.flink.streaming.runtime.tasks.StreamTask.runWithCleanUpOnFail(StreamTask.java:647) ~[flink-dist_2.11-1.13.2.jar:1.13.2] at org.apache.flink.streaming.runtime.tasks.StreamTask.restore(StreamTask.java:537) ~[flink-dist_2.11-1.13.2.jar:1.13.2] at org.apache.flink.runtime.taskmanager.Task.doRun(Task.java:759) ~[flink-dist_2.11-1.13.2.jar:1.13.2] at org.apache.flink.runtime.taskmanager.Task.run(Task.java:566) ~[flink-dist_2.11-1.13.2.jar:1.13.2] at java.lang.Thread.run(Thread.java:748) ~[?:1.8.0_162] Then I searched the web, got one answer that can solve this issue: config "classloader.resolve-order: parent-first" in flink-conf.yaml Indeed, it works for this issue. But unfortunately, I'm not allowed to change the classloader.resolve-order to parent-first, it must be clild-first. As parent-first will brought me other classload related issues. Then I tried below configuration in flink-conf.yaml: classloader.parent-first-patterns.additional: org.apache.commons.collections It can solve that exception, but it's very wired this could cause other issues. So my question is, is there other ways to solve the exception above? Thanks so much for you help! Thanks && Regards, Hunk