Re: Loading FlinkKafkaProducer fails with LinkError

Posted by Arvid Heise-3 on
URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/Loading-FlinkKafkaProducer-fails-with-LinkError-tp37611p37671.html

Hi Yuval,

How do you execute Flink? Can you show us the log entry with the classpath?

I'm guessing that you have Kafka bundled in your uber-jar and additionally also have the connector in flink-dist/lib. If so, you simply need to remove it in one place. In general, if you use flink-dist, you'd not bundle any Flink dependencies in your uber-jar (use provided scope for them).

If you have everything bundled in one uber-jar and execute it somehow without flink-dist, then I don't immediately see a solution. Then the log with the classpath would help.

Best,

Arvid

On Sun, Aug 23, 2020 at 1:37 PM Yuval Itzchakov <[hidden email]> wrote:

Hi,

I'm trying to load a FlinkKafkaProducer sink alongside another custom sink. While trying to restore

a running Flink app from the previous state, I get the error message below.

I am running Flink 1.9.0 with the following SBT dependency added:

"org.apache.flink" %% "flink-connector-kafka" % 1.9.0

And the app is deployed via a standard uber jar with all the dependencies. W

Would appreciate the help

java.lang.LinkageError: loader constraint violation: loader (instance of org/apache/flink/util/ChildFirstClassLoader) previously initiated loading for a different type with name "org/apache/kafka/clients/producer/ProducerRecord"

    at java.lang.ClassLoader.defineClass1(Native Method)

    at java.lang.ClassLoader.defineClass(ClassLoader.java:763)

    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)

    at java.net.URLClassLoader.defineClass(URLClassLoader.java:468)

    at java.net.URLClassLoader.access$100(URLClassLoader.java:74)

    at java.net.URLClassLoader$1.run(URLClassLoader.java:369)

    at java.net.URLClassLoader$1.run(URLClassLoader.java:363)

    at java.security.AccessController.doPrivileged(Native Method)

    at java.net.URLClassLoader.findClass(URLClassLoader.java:362)

    at org.apache.flink.util.ChildFirstClassLoader.loadClass(ChildFirstClassLoader.java:66)

    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)

    at java.lang.Class.getDeclaredMethods0(Native Method)

    at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)

    at java.lang.Class.getDeclaredMethod(Class.java:2128)

    at java.io.ObjectStreamClass.getPrivateMethod(ObjectStreamClass.java:1629)

    at java.io.ObjectStreamClass.access$1700(ObjectStreamClass.java:79)

    at java.io.ObjectStreamClass$3.run(ObjectStreamClass.java:520)

    at java.io.ObjectStreamClass$3.run(ObjectStreamClass.java:494)

    at java.security.AccessController.doPrivileged(Native Method)

    at java.io.ObjectStreamClass.<init>(ObjectStreamClass.java:494)

    at java.io.ObjectStreamClass.lookup(ObjectStreamClass.java:391)

    at java.io.ObjectStreamClass.initNonProxy(ObjectStreamClass.java:681)

    at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1885)

    at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1751)

    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2042)

    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1573)

    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2287)

    at java.io.ObjectInputStream.defaultReadObject(ObjectInputStream.java:561)

    at org.apache.flink.streaming.connectors.kafka.FlinkKafkaProducer.readObject(FlinkKafkaProducer.java:1202)

    at sun.reflect.GeneratedMethodAccessor358.invoke(Unknown Source)

    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

    at java.lang.reflect.Method.invoke(Method.java:498)

    at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:1170)

    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2178)

    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2069)

    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1573)

    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2287)

    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2211)

    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2069)

    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1573)

    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2287)

    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2211)

    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2069)

    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1573)

    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:431)

    at org.apache.flink.util.InstantiationUtil.deserializeObject(InstantiationUtil.java:576)

    at org.apache.flink.util.InstantiationUtil.deserializeObject(InstantiationUtil.java:562)

    at org.apache.flink.util.InstantiationUtil.deserializeObject(InstantiationUtil.java:550)

    at org.apache.flink.util.InstantiationUtil.readObjectFromConfig(InstantiationUtil.java:511)

    at org.apache.flink.streaming.api.graph.StreamConfig.getStreamOperatorFactory(StreamConfig.java:235)

    at org.apache.flink.streaming.runtime.tasks.OperatorChain.createChainedOperator(OperatorChain.java:427)

    at org.apache.flink.streaming.runtime.tasks.OperatorChain.createOutputCollector(OperatorChain.java:354)

    at org.apache.flink.streaming.runtime.tasks.OperatorChain.createChainedOperator(OperatorChain.java:418)

    at org.apache.flink.streaming.runtime.tasks.OperatorChain.createOutputCollector(OperatorChain.java:354)

    at org.apache.flink.streaming.runtime.tasks.OperatorChain.createChainedOperator(OperatorChain.java:418)

    at org.apache.flink.streaming.runtime.tasks.OperatorChain.createOutputCollector(OperatorChain.java:354)

    at org.apache.flink.streaming.runtime.tasks.OperatorChain.createChainedOperator(OperatorChain.java:418)

    at org.apache.flink.streaming.runtime.tasks.OperatorChain.createOutputCollector(OperatorChain.java:354)

    at org.apache.flink.streaming.runtime.tasks.OperatorChain.createChainedOperator(OperatorChain.java:418)

    at org.apache.flink.streaming.runtime.tasks.OperatorChain.createOutputCollector(OperatorChain.java:354)

    at org.apache.flink.streaming.runtime.tasks.OperatorChain.createChainedOperator(OperatorChain.java:418)

    at org.apache.flink.streaming.runtime.tasks.OperatorChain.createOutputCollector(OperatorChain.java:354)

    at org.apache.flink.streaming.runtime.tasks.OperatorChain.createChainedOperator(OperatorChain.java:418)

    at org.apache.flink.streaming.runtime.tasks.OperatorChain.createOutputCollector(OperatorChain.java:354)

    at org.apache.flink.streaming.runtime.tasks.OperatorChain.createChainedOperator(OperatorChain.java:418)

    at org.apache.flink.streaming.runtime.tasks.OperatorChain.createOutputCollector(OperatorChain.java:354)

    at org.apache.flink.streaming.runtime.tasks.OperatorChain.<init>(OperatorChain.java:144)

    at org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:370)

    at org.apache.flink.runtime.taskmanager.Task.doRun(Task.java:705)

    at org.apache.flink.runtime.taskmanager.Task.run(Task.java:530)

    at java.lang.Thread.run(Thread.java:748)

--

Best Regards,
Yuval Itzchakov.

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