[
https://issues.apache.org/jira/browse/FLINK-18464?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17368724#comment-17368724
]
Yun Tang commented on FLINK-18464:
----------------------------------
[~guxiangfly], namespace is allowed to change, which is used in WindowOperator
as window processing would have different windows.
If you want to take this ticket, and one of the solutions I could think of is
that checking whether previous stored state descriptor and namespace serializer
are the same as current registered one. By doing so, we could avoid changed
namespace serializer for a single state. However, the main concern is that
current {{AbstractKeyedStateBackend#getPartitionedState}} method also act as
caching states for performance and another check here might impact the
performance and we need to do some tests to verify.
> ClassCastException during namespace serialization for checkpoint (Heap and
> RocksDB)
> -----------------------------------------------------------------------------------
>
> Key: FLINK-18464
> URL: https://issues.apache.org/jira/browse/FLINK-18464
> Project: Flink
> Issue Type: Bug
> Components: Runtime / Checkpointing, Runtime / State Backends
> Affects Versions: 1.9.3, 1.13.1
> Reporter: Roman Khachatryan
> Priority: Major
> Labels: pull-request-available
> Attachments: image-2021-06-21-20-06-51-323.png,
> image-2021-06-21-20-07-30-281.png, image-2021-06-21-20-07-43-246.png,
> image-2021-06-21-20-33-39-295.png, image-2021-06-23-14-34-37-703.png,
> image-2021-06-24-16-41-54-425.png
>
>
> (see FLINK-23036 for error details with RocksDB)
>
> From
> [thread|http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/Checkpoint-failed-because-of-TimeWindow-cannot-be-cast-to-VoidNamespace-td36310.html]
> {quote}I'm using flink 1.9 on Mesos and I try to use my own trigger and
> evictor. The state is stored to memory.
> {quote}
>
>
> {code:java}
> input.setParallelism(processParallelism)
> .assignTimestampsAndWatermarks(new UETimeAssigner)
> .keyBy(_.key)
> .window(TumblingEventTimeWindows.of(Time.minutes(20)))
> .trigger(new MyTrigger)
> .evictor(new MyEvictor)
> .process(new MyFunction).setParallelism(aggregateParallelism)
> .addSink(kafkaSink).setParallelism(sinkParallelism)
> .name("kafka-record-sink"){code}
>
>
> {code:java}
> java.lang.Exception: Could not materialize checkpoint 1 for operator
> Window(TumblingEventTimeWindows(1200000), JoinTrigger, JoinEvictor,
> ScalaProcessWindowFunctionWrapper) -> Sink: kafka-record-sink (2/5).
> at
> org.apache.flink.streaming.runtime.tasks.StreamTask$AsyncCheckpointRunnable.handleExecutionException(StreamTask.java:1100)
> at
> org.apache.flink.streaming.runtime.tasks.StreamTask$AsyncCheckpointRunnable.run(StreamTask.java:1042)
> at
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
> at java.lang.Thread.run(Thread.java:748)
> Caused by: java.util.concurrent.ExecutionException:
> java.lang.ClassCastException:
> org.apache.flink.streaming.api.windowing.windows.TimeWindow cannot be cast to
> org.apache.flink.runtime.state.VoidNamespace
> at java.util.concurrent.FutureTask.report(FutureTask.java:122)
> at java.util.concurrent.FutureTask.get(FutureTask.java:192)
> at
> org.apache.flink.runtime.concurrent.FutureUtils.runIfNotDoneAndGet(FutureUtils.java:450)
> at
> org.apache.flink.streaming.api.operators.OperatorSnapshotFinalizer.<init>(OperatorSnapshotFinalizer.java:47)
> at
> org.apache.flink.streaming.runtime.tasks.StreamTask$AsyncCheckpointRunnable.run(StreamTask.java:1011)
>
> ... 3 more
> Caused by: java.lang.ClassCastException:
> org.apache.flink.streaming.api.windowing.windows.TimeWindow cannot be cast to
> org.apache.flink.runtime.state.VoidNamespace
> at
> org.apache.flink.runtime.state.VoidNamespaceSerializer.serialize(VoidNamespaceSerializer.java:32)
> at
> org.apache.flink.runtime.state.heap.CopyOnWriteStateMapSnapshot.writeState(CopyOnWriteStateMapSnapshot.java:114)
> at
> org.apache.flink.runtime.state.heap.AbstractStateTableSnapshot.writeStateInKeyGroup(AbstractStateTableSnapshot.java:121)
> at
> org.apache.flink.runtime.state.heap.CopyOnWriteStateTableSnapshot.writeStateInKeyGroup(CopyOnWriteStateTableSnapshot.java:37)
> at
> org.apache.flink.runtime.state.heap.HeapSnapshotStrategy$1.callInternal(HeapSnapshotStrategy.java:191)
> at
> org.apache.flink.runtime.state.heap.HeapSnapshotStrategy$1.callInternal(HeapSnapshotStrategy.java:158)
> at
> org.apache.flink.runtime.state.AsyncSnapshotCallable.call(AsyncSnapshotCallable.java:75)
> at java.util.concurrent.FutureTask.run(FutureTask.java:266)
> at
> org.apache.flink.runtime.concurrent.FutureUtils.runIfNotDoneAndGet(FutureUtils.java:447)
>
> ... 5 more
> {code}
>
>
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
