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https://issues.apache.org/jira/browse/FLINK-13910?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17000092#comment-17000092
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Dawid Wysakowicz commented on FLINK-13910:
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I agree with [~twalthr] and [~aljoscha].
Moreover I am not sure if the root cause for what you're describing (job
submission from 1.x.x to 1.x.y) is mismatch in serialVersionUid. Imo the
problem is that a wrong classloader is being used for reading that class. If it
is being submitted from the client, than the user classloader should be used
and there should be no mismatch in a serialVersionUid. Therefore I think in
this case serialVersionUid would just hide the problem.
I also do support the {{1L}} for serialVersionUIDs, as Timo said we should not
need to maintain compatibility of those classes between major versions.
> Many serializable classes have no explicit 'serialVersionUID'
> -------------------------------------------------------------
>
> Key: FLINK-13910
> URL: https://issues.apache.org/jira/browse/FLINK-13910
> Project: Flink
> Issue Type: Bug
> Components: API / Type Serialization System
> Reporter: Yun Tang
> Assignee: Yun Tang
> Priority: Critical
> Labels: pull-request-available
> Fix For: 1.9.2, 1.10.0
>
> Attachments: SerializableNoSerialVersionUIDField
>
> Time Spent: 20m
> Remaining Estimate: 0h
>
> Currently, many serializable classes in Flink have no explicit
> 'serialVersionUID'. As [official
> doc|https://flink.apache.org/contributing/code-style-and-quality-java.html#java-serialization]
> said, {{Serializable classes must define a Serial Version UID}}.
> No 'serialVersionUID' would cause compatibility problem. Take
> {{TwoPhaseCommitSinkFunction}} for example, since no explicit
> 'serialVersionUID' defined, after
> [FLINK-10455|https://github.com/apache/flink/commit/489be82a6d93057ed4a3f9bf38ef50d01d11d96b]
> introduced, its default 'serialVersionUID' has changed from
> "4584405056408828651" to "4064406918549730832". In other words, if we submit
> a job from Flink-1.6.3 local home to remote Flink-1.6.2 cluster with the
> usage of {{TwoPhaseCommitSinkFunction}}, we would get exception like:
> {code:java}
> org.apache.flink.streaming.runtime.tasks.StreamTaskException: Cannot
> instantiate user function.
> at
> org.apache.flink.streaming.api.graph.StreamConfig.getStreamOperator(StreamConfig.java:239)
> at
> org.apache.flink.streaming.runtime.tasks.OperatorChain.<init>(OperatorChain.java:104)
> at
> org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:267)
> at org.apache.flink.runtime.taskmanager.Task.run(Task.java:711)
> at java.lang.Thread.run(Thread.java:748)
> Caused by: java.io.InvalidClassException:
> org.apache.flink.streaming.api.functions.sink.TwoPhaseCommitSinkFunction;
> local class incompatible: stream classdesc serialVersionUID =
> 4584405056408828651, local class serialVersionUID = 4064406918549730832
> at java.io.ObjectStreamClass.initNonProxy(ObjectStreamClass.java:699)
> at
> java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1885)
> at
> java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1751)
> 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.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:537)
> at
> org.apache.flink.util.InstantiationUtil.deserializeObject(InstantiationUtil.java:524)
> at
> org.apache.flink.util.InstantiationUtil.deserializeObject(InstantiationUtil.java:512)
> at
> org.apache.flink.util.InstantiationUtil.readObjectFromConfig(InstantiationUtil.java:473)
> at
> org.apache.flink.streaming.api.graph.StreamConfig.getStreamOperator(StreamConfig.java:224)
> ... 4 more
> {code}
> Similar problems existed in
> {{org.apache.flink.streaming.api.operators.SimpleOperatorFactory}} which has
> different 'serialVersionUID' from release-1.9 and current master branch.
> IMO, we might have two options to fix this bug:
> # Add explicit serialVersionUID for those classes which is identical to
> latest Flink-1.9.0 release code.
> # Use similar mechanism like {{FailureTolerantObjectInputStream}} in
> {{InstantiationUtil}} to ignore serialVersionUID mismatch.
> I have collected all production classes without serialVersionUID from latest
> master branch in the attachment, which counts to 639 classes.
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