Apache kafka 弹簧嵌入式卡夫卡&x2B；模拟架构注册表：未注册状态存储更改日志架构

我正在为我们的kafka系统构建一个集成测试，使用的是MockSchemaRegistrCyclient。我正在为我们的一个流拓扑构建一个测试，它是使用Streams API（KStreamBuilder）构建的。这个特定拓扑有一个KStream（stream1）传入一个KTable（表1）

当我将来自table1的KTableProcessor的输入馈送到stream1时，我遇到了一个错误：

Exception in thread "mortgage-kafka-consumers-it-c1dd9185-ce16-415c-ad82-293c1281c897-StreamThread-1" org.apache.kafka.streams.errors.StreamsException: Exception caught in process. taskId=0_0, processor=KSTREAM-SOURCE-0000000001, topic=streaming.mortgage.application_party, partition=0, offset=0
    at org.apache.kafka.streams.processor.internals.StreamTask.process(StreamTask.java:202)
    at org.apache.kafka.streams.processor.internals.AssignedTasks$2.apply(AssignedTasks.java:342)
    at org.apache.kafka.streams.processor.internals.AssignedTasks.applyToRunningTasks(AssignedTasks.java:415)
    at org.apache.kafka.streams.processor.internals.AssignedTasks.process(AssignedTasks.java:334)
    at org.apache.kafka.streams.processor.internals.StreamThread.processAndPunctuate(StreamThread.java:624)
    at org.apache.kafka.streams.processor.internals.StreamThread.runOnce(StreamThread.java:513)
    at org.apache.kafka.streams.processor.internals.StreamThread.runLoop(StreamThread.java:480)
    at org.apache.kafka.streams.processor.internals.StreamThread.run(StreamThread.java:457)
Caused by: org.apache.kafka.common.errors.SerializationException: Error deserializing Avro message for id 6
**Caused by: java.io.IOException: Cannot get schema from schema registry!**
    at io.confluent.kafka.schemaregistry.client.MockSchemaRegistryClient.getSchemaBySubjectAndIdFromRegistry(MockSchemaRegistryClient.java:106)
    at io.confluent.kafka.schemaregistry.client.MockSchemaRegistryClient.getBySubjectAndID(MockSchemaRegistryClient.java:149)
    at io.confluent.kafka.serializers.AbstractKafkaAvroDeserializer.deserialize(AbstractKafkaAvroDeserializer.java:121)
    at io.confluent.kafka.serializers.AbstractKafkaAvroDeserializer.deserialize(AbstractKafkaAvroDeserializer.java:92)
    at io.confluent.kafka.serializers.KafkaAvroDeserializer.deserialize(KafkaAvroDeserializer.java:54)
    at com.sofi.kafka.serialization.AvroDeserializer.deserialize(AvroDeserializer.java:35)
    at org.apache.kafka.streams.state.StateSerdes.valueFrom(StateSerdes.java:163)
    at org.apache.kafka.streams.state.internals.CachingKeyValueStore.get(CachingKeyValueStore.java:151)
    at org.apache.kafka.streams.state.internals.CachingKeyValueStore.get(CachingKeyValueStore.java:135)
    at org.apache.kafka.streams.kstream.internals.KTableSource$KTableSourceProcessor.process(KTableSource.java:62)
    at org.apache.kafka.streams.processor.internals.ProcessorNode$1.run(ProcessorNode.java:45)
    at org.apache.kafka.streams.processor.internals.StreamsMetricsImpl.measureLatencyNs(StreamsMetricsImpl.java:201)
    at org.apache.kafka.streams.processor.internals.ProcessorNode.process(ProcessorNode.java:131)
    at org.apache.kafka.streams.processor.internals.ProcessorContextImpl.forward(ProcessorContextImpl.java:82)
    at org.apache.kafka.streams.processor.internals.SourceNode.process(SourceNode.java:80)
    at org.apache.kafka.streams.processor.internals.StreamTask.process(StreamTask.java:188)
    at org.apache.kafka.streams.processor.internals.AssignedTasks$2.apply(AssignedTasks.java:342)
    at org.apache.kafka.streams.processor.internals.AssignedTasks.applyToRunningTasks(AssignedTasks.java:415)
    at org.apache.kafka.streams.processor.internals.AssignedTasks.process(AssignedTasks.java:334)
    at org.apache.kafka.streams.processor.internals.StreamThread.processAndPunctuate(StreamThread.java:624)
    at org.apache.kafka.streams.processor.internals.StreamThread.runOnce(StreamThread.java:513)
    at org.apache.kafka.streams.processor.internals.StreamThread.runLoop(StreamThread.java:480)
    at org.apache.kafka.streams.processor.internals.StreamThread.run(StreamThread.java:457)

The KTableProcessor is attempting to deserialize an entry from the RocksDB state store, however the schema does not exist in the mock schema registry. The topic whose schema is being requested is: **appname-KTABLE-SOURCE-STATE-STORE-0000000000-changelog**

As the exception states, the schema has not been registered. However, the topic **appname-KTABLE-SOURCE-STATE-STORE-0000000000-changelog-key** does have a registered schema (registered when the entry's key is serialized for the query). 

Since this is an internal topic, I don't expect to have to register this schema myself, however I'm failing because of the schema's absence in the registry. Is there a way to have changelog schemas registered prior to data ingestion? Is there a way to disable state store changelogging with the KStreamBuilder?

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提前谢谢

解决了这个问题，我现在将不好意思地重新叙述：当将KTable（通过Streams API）与嵌入式kafka代理一起使用时，您将需要为KafkaStreams对象配置一个状态存储目录，该目录对于嵌入式kafka代理的每次运行都是唯一的（在我的例子中，是测试的每次运行）

您可以通过

StreamsConfig.State\u DIR\u CONFIG

配置来控制状态存储目录。我通过在默认的状态存储目录中附加一个时间戳使其唯一

properties.put(StreamsConfig.STATE_DIR_CONFIG, "/tmp/kraken-streams/" + LocalDateTime.now().toString());

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问题是每次初始化嵌入式kafka代理时，同一位置都存在一个旧的状态存储。当第一条记录被输入到KTable的主题中时，状态存储能够返回以前的值。这导致尝试反序列化尚未（就架构注册表实例而言）序列化的状态存储记录。架构仅在序列化时注册，因此由于缺少已注册架构，因此尝试反序列化失败

我按照你的建议做了，但是我还是得到了同样的例外。我检查了我的STATE\u DIR\u CONFIG，它是动态工作的（带有时间戳）。我甚至删除了以前的所有状态，但这对我没有帮助。这在windows上不起作用<代码>/tmp在那里不存在