Luke Stephenson created KAFKA-8143:
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Summary: Kafka-Streams GlobalStore cannot be read after
application restart
Key: KAFKA-8143
URL: https://issues.apache.org/jira/browse/KAFKA-8143
Project: Kafka
Issue Type: Bug
Components: streams
Affects Versions: 2.1.1
Reporter: Luke Stephenson
I've created a small example application which has a trivial `Processor` which
takes messages and stores the length of the String value rather than the value
itself.
That is, the following setup:
{code:java}
Topic[String, String]
Processor[String, String]
KeyValueStore[String, Long] // Note the Store persists Long values
{code}
The example application also has a Thread which periodically displays all
values in the KeyValueStore.
While the application is run, I can publish values to the topic with:
{code:java}
root@kafka:/opt/kafka# bin/kafka-console-producer.sh --property
"parse.key=true" --property "key.separator=:" --broker-list localhost:9092
--topic test.topic
>1:hello
>2:abc{code}
And the background Thread will report the values persisted to the key value
store.
If the application is restarted, when attempting to read from the KeyValueStore
it will fail. It attempts to recover the state from the persistent RocksDB
store which fails with:
{code:java}
org.apache.kafka.common.errors.SerializationException: Size of data received by
LongDeserializer is not 8{code}
(Note there is no stack trace as SerializationException has disabled it.)
Debugging appears to reveal that the original data from the Topic is being
restored rather than what was modified by the processor.
I've created a minimal example to show the issue at
[https://github.com/lukestephenson/kafka-streams-example]
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