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https://issues.apache.org/jira/browse/KAFKA-4311?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15597385#comment-15597385
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Damian Guy commented on KAFKA-4311:
-----------------------------------
Frank, thanks for testing this for me. I just pushed another minor changing
fixing a potential reason this could happen. I'm not sure it is the reason it
is happening in your case as i'm unable to reproduce this specific issue. If
you wouldn't mind trying out https://github.com/dguy/kafka/tree/kafka-4311
again, it would be really appreciated.
I'm going to be out for the next week, but hopefully someone else will be able
to look into into it further.
Thanks for your help so far.
Regards,
Damian
> Multi layer cache eviction causes forwarding to incorrect ProcessorNode
> ------------------------------------------------------------------------
>
> Key: KAFKA-4311
> URL: https://issues.apache.org/jira/browse/KAFKA-4311
> Project: Kafka
> Issue Type: Bug
> Components: streams
> Affects Versions: 0.10.1.0
> Reporter: Damian Guy
> Assignee: Damian Guy
> Fix For: 0.10.1.1
>
>
> The two exceptions below were reported by Frank on the dev mailing list.
> After investigation, the root cause is multiple cache evictions happening in
> the same topology.
> Given a topology like the one below. If a record arriving in `tableOne`
> causes a cache eviction, it will trigger the `leftJoin` that will do a `get`
> from `reducer-store`. If the key is not currently cached in `reducer-store`,
> but is in the backing store, it will be put into the cache, and it may also
> trigger an eviction. If it does trigger an eviction and the eldest entry is
> dirty it will flush the dirty keys. It is at this point that the exception in
> the comment happens (ClassCastException). This occurs because the
> ProcessorContext is still set to the context of the `leftJoin` and the next
> child in the topology is `mapValues`.
> We need to set the correct `ProcessorNode`, on the context, in the
> `ForwardingCacheFlushListener` prior to calling `context.forward`. We also
> need to set remember to reset the `ProcessorNode` to the previous node once
> `context.forward` has completed.
> {code}
> final KTable<String, String> one = builder.table(Serdes.String(),
> Serdes.String(), tableOne, tableOne);
> final KTable<Long, String> two = builder.table(Serdes.Long(),
> Serdes.String(), tableTwo, tableTwo);
> final KTable<String, Long> reduce = two.groupBy(new
> KeyValueMapper<Long, String, KeyValue<String, Long>>() {
> @Override
> public KeyValue<String, Long> apply(final Long key, final String
> value) {
> return new KeyValue<>(value, key);
> }
> }, Serdes.String(), Serdes.Long())
> .reduce(new Reducer<Long>() {
> @Override
> public Long apply(final Long value1, final Long value2) {
> return value1 + value2;
> }
> }, new Reducer<Long>() {
> @Override
> public Long apply(final Long value1, final Long value2) {
> return value1 - value2;
> }
> }, "reducer-store");
> one.leftJoin(reduce, new ValueJoiner<String, Long, String>() {
> @Override
> public String apply(final String value1, final Long value2) {
> return value1 + ":" + value2;
> }
> })
> .mapValues(new ValueMapper<String, String>() {
> @Override
> public String apply(final String value) {
> return value;
> }
> });
> {code}
> This exception is actually a symptom of the exception reported below in the
> comment. After the first exception is thrown, the StreamThread triggers a
> shutdown that then throws this exception.
> [StreamThread-1] ERROR
> org.apache.kafka.streams.processor.internals.StreamThread - stream-thread
> [StreamThread-1] Failed to close state manager for StreamTask 0_0:
> org.apache.kafka.streams.errors.ProcessorStateException: task [0_0] Failed
> to close state store addr-organization
> at
> org.apache.kafka.streams.processor.internals.ProcessorStateManager.close(ProcessorStateManager.java:342)
> at
> org.apache.kafka.streams.processor.internals.AbstractTask.closeStateManager(AbstractTask.java:121)
> at
> org.apache.kafka.streams.processor.internals.StreamThread$2.apply(StreamThread.java:341)
> at
> org.apache.kafka.streams.processor.internals.StreamThread.performOnAllTasks(StreamThread.java:322)
> at
> org.apache.kafka.streams.processor.internals.StreamThread.closeAllStateManagers(StreamThread.java:338)
> at
> org.apache.kafka.streams.processor.internals.StreamThread.shutdownTasksAndState(StreamThread.java:299)
> at
> org.apache.kafka.streams.processor.internals.StreamThread.shutdown(StreamThread.java:262)
> at
> org.apache.kafka.streams.processor.internals.StreamThread.run(StreamThread.java:245)
> Caused by: java.lang.IllegalStateException: Key found in dirty key set, but
> entry is null
> at
> org.apache.kafka.streams.state.internals.NamedCache.flush(NamedCache.java:112)
> at
> org.apache.kafka.streams.state.internals.ThreadCache.flush(ThreadCache.java:100)
> at
> org.apache.kafka.streams.state.internals.CachingKeyValueStore.flush(CachingKeyValueStore.java:111)
> at
> org.apache.kafka.streams.state.internals.CachingKeyValueStore.close(CachingKeyValueStore.java:117)
> at
> org.apache.kafka.streams.processor.internals.ProcessorStateManager.close(ProcessorStateManager.java:340)
> ... 7 more
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